1948 KB5 Railway Express


The place to put your K or KB "Build Off" story.

Rusty Driver
Rusty Driver

Posts: 195

Joined: Mon Sep 04, 2017 6:22 pm

Post Sun Feb 28, 2021 8:07 pm

Re: 1948 KB5 Railway Express

Part 2 - KB5 Rear Brake Drums

I needed a tool to install the bearing races. Bearing races are all the same on the KB5 - so one tool will do them all. The problem here is that the races are sunk down inside the brake drum's hub and with an automobile, I use a flat plate on top of the race and drive it in as they are not sunk down into the hub hole. These races are too big to just use something to hammer the edges, and at this size, you can't get them started without them flipping up on the side you are trying to drive in. A local shop could press them in, but I felt I could do this myself by making a tool to do it.

Pic #1 - Got some scrap pieces at work. I used a small section of a trailer spring on top of a bottom plate. The top piece measures 4 5/16" across and I contoured the ends to match the outside of the bearing race. It is 3" wide and 7/8" thick.

Pic #2 - The bottom plate is 1/4" flat steel and measures 4" diameter so it will fit inside the race. It must fit tight into the race opening as you don't want it shifting around. The plate must have a taper ground in it to follow the taper of the race so as not to cut/damage the race. I tapered the plate and test fit until the top of the plate was flush with the top of the bearing race.

I sandblasted both parts to get a clean and roughed up surface. I used JB Weld to bond the spring piece to the plate using a clamp to get the 2 pieces tight, BUT you want to use an old race so as to center the bottom plate onto the spring piece - which should be about a 3/16" overhang on each side. The JB Weld will squeeze out and you will have to clean it up after it cures.

Pic #3 - Unclamp and clean-up the parts and the bearing race should fit squarely and snug on the bottom plate. You can see how the spring piece overhangs the race edge and this is what will be driving the race into the hub. Test fit the tool into the drum's hub, front & back, as I had to grind a little more clearance on the spring piece's ends to allow the tool to drop in without hitting the inside edges of the hub.

The tool is now ready to install the bearing races.
Attachments
01  Bearing Race Tool.JPG
02  Bearing Race Tool.JPG
03  Bearing Race Tool.JPG

Rusty Driver
Rusty Driver

Posts: 195

Joined: Mon Sep 04, 2017 6:22 pm

Post Sun Feb 28, 2021 8:16 pm

Re: 1948 KB5 Railway Express

Part 3 - KB5 Rear Brake Drums

Pic #1 & #2 - I cleaned up the inside of the drum by hitting it with my sandblaster to knock off any loose rust and cleaned up the braking surface as well and blew this off with my air gun. I thoroughly cleaned up all the remaining grease in the inner hub using Brake Clean, rags, and air to blow it out & dry. I used high temperature silver to spray paint the inside area.

Pic #3 - From left to right, my home made tool to knock in the bearing races, the inner bearing & race (Timken #395S & 394A), inner steel retaining shim, felt seals, and outer steel retaining shim, and the spring wire snap ring that holds the seal "sandwich" in place within the drum.

Pic #4 - #6 - I inserted the bearing race down into the hub. Then set my race tool on top of it. It locks inside the bearing race and is shaped & clearanced to fit down inside the hub. Next I used a hardened steel pin I got from my workplace, a locking "pull pin" used at the rear axle/tandems on a big truck trailer, and the big hammer to hit the bearing tool and knock the race down into the hub. Took a little force to knock these in, not as easy as doing it on my cars. I made sure the race was being driven in squarely by observing the top of the race tool. If it looks like it is higher in one area (tilted), I would move the pin over to the higher side to favor it when I hit the pin with the hammer. I also moved the race tool around to different positions on the race to get it to sink evenly into the machined hub. DON'T allow the race to go in at an angle which is easier to do when first seating th race, it must be driven in evenly, so take your time and check after each hammer hit and adjust your hits accordingly. If the race appears to have gotten a large uneven slant to it as it is being driven in, knock it back out and start again, don't force it straight by beating hard on the side that is higher to bring it down even again. CAREFUL, as you can only get the tool so far down as it will hit the edge of the hub when the race insert comes level to the machined hub - the race sits deeper within the hub than the tool can knock it down (same as any automobile). So when you hit this point stop. You can see the differences in height of the tool in Pic #4 and the bearing seated down in the hub in Pic #6.

Pic #7 - To get the race completely seated, I do what I do with my cars. I use an old race to knock the new race all the way in. The race has a taper to match the bearing taper, so it has a wide width and narrow width. You want to use the narrow width to be placed on the new race so as to drive it in. The wider section is rolled on the edges and won't seat squarely on the new race and could damage it. The problem will be once you drive the new race in to seat it, you cannot get the old race out because of the tight fit into the hub and you don't have a lip to grab seeing both races are identical in size at the narrower width. First I notch a step, or lip, into the old race. I use my die grinder and cut-off disc to grind a notch into the wider width of the race. I grind it deep enough to be able to catch the end of a flat bladed screw driver, as shown. Then when I am ready to remove the old race from the hub, I can grab the race with my screw driver blade and knock it back out of the hub with a few light hammer taps.

Pic #8 & #9 - Here the old race is installed and you can see the back, the wider width, of the race with its numbers on it. The narrower width is face down on top of the new race. It should lay right on top evenly with the two surfaces butted together. Mine seemed to self locate just a tad, so it stayed in place. But if it slides easily, you could use something like masking tape and tape the 2 together where they butt on the inside of the race to hold them in place. Then I put my race tool on top of the old race and gave it a tap to seat it. Take the tool off to ensure the old race did not slip off. Repeat as needed. The race should be driven until the new race seats into the machined hole of the hub. You can usually tell when it is fully seated, it will have a "solid" sound when you hit the tool with the hammer. Then visually look to see that the new race is fully seated and no gap/space is seen, or felt, between the race and the machined ledge in the hub. Once it looks good, use the flat bladed screw driver and catch the notch in the old race you made earlier and drive the old race out of the hub. The inner race is now ready for the bearing and seals.

Pic #10 & #11 - Next up is the smaller outer bearing, Timken #390 & #394A. Both the inner and outer bearings use the same race, so the race tool and old notched race can be used for both applications. The outer race is done just like the inner. Knock it in with the race tool until it stops, then use the old race with the notch and drive it in until it bottoms. Then remove the old race and it is ready for its bearing. You can see how far down the tool will go in Pic #14 and how tight the tool is within the hub.

Pic #12 - Now that both the inner and outer races are installed, you can install the bearings doing the inner bearing and felt seals first. I pack my wheel bearings with grease the way I was shown, by hand, no special bearing packing tool. So a pair of gloves protects my hands, grab a wad of grease from the can, I used Lucas brand Red "N" Tacky Grease, and then work the bearing into the wad of grease watching to see the grease ooze out from the race and around the bearings. I pack the bearing from one side, the flip it over and pack from the other side. If you can grab the inner race and rotate it, it can work some grease into the bearings - but the grease was too heavy and bearings big, so I was not able to do this as I would have with a smaller car wheel bearing. In any case, I gave then a good going over and the bearings were thoroughly filled with grease. I also put a layer of grease on the outside of the bearing before inserting the bearing into its race in the hub. The felts have to be oil soaked before installation. The factory manual says to dip them in light oil, I used 10W-30.

Pic #13 & #14 - Problem fit. With the drum completed and ready to install, I made an attempt to put it on. The drum won't fit over the new brake shoes as there is not enough clearance. I made sure the brake shoe adjusting cams were at their low spots, and they were. I then usd a thin feeler gaug to make sure there were no "hi/low" gaps between the shoe and drum - which there were not. So the fix, and a common procedure with the older vehicles, is called "arcing" the brake shoes. A grinding machine specific for brake lining "arcing" uses a sanding drum/disc to remove material from the brake lining to match the arc/curve of the brake drum after it has been turned and to get the needed clearances between drum & lining. I don't want to turn the drums and remove any metal, and I don't want to $$send the drum/shoes out to have this done. So I am going to fabricate another "home made" tool that will enable me to take some material off the brake lining to get the drum to fit over the brake shoes. I will most likely have to do the passenger side as well. So that will be my next installment in this story.
Attachments
01  Drum blasted.JPG
02  Drum Painted.JPG
03  Tool & Inner Bearing.JPG
04  Race Tool.JPG
05  Pin & Hammer.JPG
06  Bearing Knocked In.JPG
07  Old Race Notched.JPG
08  Old Race Installed.JPG
09  Driving New Race In.JPG
10  Outer Race Seated.JPG
11  Outer Race Installed.JPG
12  Inner Bearing & Seals In.JPG
13  No Go.JPG
14  No Clearance.JPG

Rusty Driver
Rusty Driver

Posts: 195

Joined: Mon Sep 04, 2017 6:22 pm

Post Sun Apr 11, 2021 7:53 pm

Re: 1948 KB5 Railway Express

REAR BRAKE SHOES - BRAKE LINING GRINDER

Finally getting some good weekend weather to get back onto the rear brakes.

I made a tool to grind down the brake linings of the KB5 brake shoes after I found that the brake drum would not go over the newly installed shoes. Did a little research and found that grinding down brake linings to fit the drums was commonly done on the older vehicles and right on up through the 1970's by some brake shops - the difference is that they used a machine specifically for this purpose and I was going to free-style it by hand. I talked with a work associate who worked in a truck/trailer shop and he said he used to grind down lining by hand using a belt or circular sander - and he never had any issues.

Pic #01 - So I built my brake lining grinder using a large flat piece of finished wood and piece of sheet aluminum I got from work. I screwed the aluminum to the wood to provide a smooth surface to roll the brake shoes over. Then I used a 1/8" flat steel plate I had to lift the belt sander up off the aluminum seeing I was laying the belt sander on its side. I used screws to hold it in place.

Pic #02 - The belt sander laid on its side on top of the steel plate to allow the sanding belt to turn freely. I used an 80 grit paper on the belt sander.

Pic #03 - To secure the belt sander, I used a short length of 2x4 and 5/16" threaded rods. I placed the 2x4 on top of the belt sander and drilled my holes on each end and passed a threaded rod through to the bottom board and marked where it hit. I then drilled a hole, cut my threaded rod to size, installed the threaded rod and secured with washers/nuts. Then did the other side to match. Tightened the rods down snug to draw the 2x4 tight over the belt sander like a clamp. This kept the belt sander from moving while I worked the brake linings against it. I also used my square to make sure the sanding belt was at a 90 degree angle to the board so as to get an even sanding of the brake lining.

Pic #04 & #05 - Here you can see how the brake shoe/lining sits against the belt sander and is ready to be sanded down.

Pic #06 - I spray painted the brake lining edge with a light dusting of silver paint and let dry. Then I used a compass which normally holds a pencil, and removed the pencil and fitted a Sharpie to it - nothing fancy, just had to secure it with some scotch tape. With the paint dry, I used my electronic micrometer to measure a width between the compass steel point and Sharpie end. Then I put the compass point on the backside of the steel shoe so as to use as a guide, and dragged the Sharpie along the edge of the lining to produce a nice black & even line I could follow in grinding down the lining. I think the Sharpie line itself was about 1/4" in width, but this was for a guide and not how much I was going to grind down.

Next I used my micrometer to measure the thickness of the brake lining/shoe to use as my beginning reference number, which was .635" thick. My plan was to grind down approximately .015" at a time and then test fit the shoes/drum to see if I needed to grind more. I did not want to "waste" brake lining material by grinding away more than needed. This method was timely and ended up taking several hours to get it right.
I had to remove both shoes from the backing plate on the axle, then grind one shoe at a time. I used an even pressure and slow smooth arcing motion up against the running sanding belt of the sander. The Sharpie line acted as a good guide as I watched the line's thickness while grinding. After a couple passes, I would measure with the micrometer which I locked down at a distance of .620", or the .015" I wanted to remove. By doing this, I was able to pass the caliper jaws over the lining and use the open distance of the jaws as a "go/no-go" gauge. If I had not ground down enough lining, I could not get the caliper jaws over the brake shoe/lining. If I could, I was where I wanted to be. This also was a good indicator for any high spots I may have had where the lining needed just a little more grinding and I would simply pass the lining over the sanding belt in a small tight arc to get just that area down. When I got it fairly good, I made 1 more easy full arc of the shoe/lining to get the lining evened out - worked well. I also had to flip the shoe upside down as the small space that was between the belt and the board due to the 1/8" steel plate left a ridge on the lining that had to be sanded down even with the rest of the lining - so flipping and grinding took care of the small ridge in fast order.

Once ground down, I had to now install the brake shoes on the backing plate. I only set the shoes on the anchor pins and used the top spring on the forward shoe to hold tight the brake shoe up into the wheel cylinder cup. The rearward shoe was held in place by the top anchor and the star wheel adjuster. Once in place, I had to lift the brake drum up and onto/over the brake shoes to check for fit. The goal was to be able to slide the drum completely onto/over the shoes, and be able to rotate the drum on its bearings with a slight drag.

My first fit did not do it, so off came the drum, and then the removal of both shoes again. I took both shoes down another .015" and tried another fit. Still no go. I did this 2 more times removing .015" and then another .020". The brake drum finally slid over the shoes with a slight drag at a measured thickness of .550" or a total of .085" that the brake lining had to be ground down. The grinding of the lining was a touch more than the Sharpie line I had drawn along the shoe lining edge.
Attachments
01  Grinding Fixture.JPG
02  Grinding Fixture.JPG
03  Grinding Fixture.JPG
04  Grinding Fixture.JPG
05  Grinding Fixture.JPG
06  Micrometer & Sharpie Compass.JPG

Rusty Driver
Rusty Driver

Posts: 195

Joined: Mon Sep 04, 2017 6:22 pm

Post Sun Apr 11, 2021 8:01 pm

Re: 1948 KB5 Railway Express

KB5 DRIVER'S SIDE REAR BRAKES, DRUM, and AXLE INSTALLATION

With the brake drum fitting, I removed it again so that I could re-attach the brake linings with all their hardware and hold down springs. Broke a thin U-clip that slips into the machined slot in the adjuster cam and secures the washer that keeps the shoe in place. I fabricated a new one using a large fender washer, opening up the hole with a step drill, grinding the inner hole thinner to slip into the machined groove, and cut off a section of the lower washer so it would fit over the groove and I could pinch it closed & tight into its groove - worked out well, but took a little extra time to do. Could have probably found one online, but that's more waiting time.

Thinking this was going to be my last time to lift up that cast iron brake drum for the day, I put it on, but it would not fully seat on the axle. I gave it a couple light taps with a heavy rubber mallet, but no good. There was about a 1" gap between the drum and backing plate. I got replacement Timken bearings and thought "oh crap, made in China" and that they were close, but not close enough. Pulled the drum off again. I grabbed an old bearing and put it on the machined collar of the spindle. Same thing, only went so far and locked up. I felt better and now figured the inner bearing race was designed to be a tight interference fit over the machined section of the axle - more so than I am used to on a car. Removed the bearing and again, hoisted the brake drum onto axle - same problem, could not seat it.

Pic #07 - I used 2 large C-clamps opposite each other and drew the drum in tight by tightening each clamp a few turns. This did the trick and slowly seated the bearing onto its race.

Pic #08 - I was then able to install the large nuts that held the brake drum onto the axle. There is the inner nut, a lock washer, then the outer nut with the felt seal that fits up against the inside/outer 8-hole flange of axle shaft. I made new axle shaft seals using Felpro gasket #3046 which is a sheet 36" x 12" x 1/32" thick. The axle shaft gasket measures 5 3/4" OD x 4" ID with 8 holes for the studs/nuts that secure it to the drum. I used my hole cutter which I had used to make my felt seals, used an old gasket to mark the 8 bolt holes, and used a paper punch to cut out the 8 smaller holes.

Pic #09 & #10 - Here is the factory KB5 axle shaft. You can see the part numbers on the end and the small "IH" stamping. Cleaned it up and made it ready for installation.

Pic #11 - Installing the inner lock nut onto the axle spindle. This holds the drum on, followed by a lock washer that keeps the nut from back out. The problem I encountered was, how tight do you tighten the nut? I could not find any torque number in the shop manual, so I did it like I do my cars. I tighten the nut up snug to ensure the bearings seated all the way on the axle tube. Then I loosened, and repeated one more time. Loosened it again and then tried to spin the drum by hand. No good. I had to use a crow bar using the threaded lugs to worm my crow bar under and rotate. Very tight in turning. So I backed off the nut more and the drum began to turn easily - a little too easy, so I tighten up a little sensing the drag of the drum by feel. I did this a couple times to get a feel for the tightness as I turned the drum by hand and could hear a slight drag of the brake shoes. Finally got it to where I felt it needed to be.

Next goes the lock washer which has a tang that fits into a machined groove in the axle tube and a folded "ear" that goes over the edge of the nut - this keeps the nut from backing off. The next problem is that the lock washer has small "teeth" that you have to bend outward to secure the outer spindle nut having the felt seal. I encountered 2 problems here.

The "teeth" are a little more than 1/16" thick, not very wide, and short stubs that are to be folded over the outer nut once the nut has been installed. There is no space to get at them to bend these tabs (you only needed to bend one) over the flat edge of the outer nut, ie pry them outward to fold them over into place. Would have been easy to knock them in as I did to remove the washer. I could not heat the small tabs to get them soft and bend them over and not set the grease on fire. I tried to pre-bend a tab thinking once the nut was on, I could get the taper of a chisel between the inner drum/tab and fold it by driving the chisel in. Problem was that when I tightened the nut, it flattened the tab back down. So, I left it as is knowing the inner nut was securely locked into place and the nut which held the bearings/drum on the spindle.

Problem #2 was the felt seal. Once I had installed the outer nut with its felt seal that goes up against the machined axle shaft pad found inside the end flange, I ran a straight edge across the felt seal and even with the outer drum's edge to which the axle shaft bolts on to. To seal correctly, the felt should stick out slightly past the drum's edge as the axle shaft compresses it to make the seal. My felt was below this. I measured one of the original seals and it was .396" (probably originally .400") thick and my new felt I made was .264" thick, a difference of .132". This had to be fixed, but I had no more felt to work with. So I needed a shim under the felt to raise it up. Being creative, I found a piece of scrap 12Volt stranded wire with its plastic coating that measured right at .130" thick. I cut a piece to fit down into the pocket of the outer nut that receives the felt, flattened it out a bit, then stuck it in place - no laughing because it seemed to have worked. I then put the felt down over my "shim" and worked it into the groove on the nut. The felt then gets oiled up because the axle flange rotates on it. I then tightened the outer nut and don't feel it is going to loosen up and if it did, it isn't going anywhere pressed up against the flange.

Pic #12 & #13 - With the outer nut/felt seal in place, I coated each side of the axle shaft gasket with a thin layer of RTV Gasket Maker #81182 made specifically for gear oils - same stuff I used on the rear end cover. Then I installed the gasket, slid the axle shaft down into the axle tube and rear gearing, and installed the 8 nuts on the drum studs to secure the axle shaft in place.

Driver's side rear brake is now complete and the drum rotates. The passenger side is next up.
Attachments
07  C-Clamps.JPG
08  Axle Shaft Gasket.JPG
09  KB5 Axle Shaft.JPG
10  KB5 Axle Shaft Number.JPG
11  Installing Inner Lock Nut.JPG
12  Outer Nut with Felt & Gasket.JPG
13  Driver Side Completed.JPG

Rusty Driver
Rusty Driver

Posts: 195

Joined: Mon Sep 04, 2017 6:22 pm

Post Fri Jun 04, 2021 7:00 pm

Re: 1948 KB5 Railway Express

I did find a Torque spec for the inner nut/bearings off the Timken Bearing site for taper bearings. Although tightening by feel can be one of experience, if you have not done a lot of brake jobs, you may not know how it should be done. So here is what I found, Timken states to tighten the axle nut to 200 ft lbs while rotating the drum/wheel. Back the nut off 1 full turn. Next re-torque nut to 50 ft lbs while rotating the drum/wheel, then back the nut off 1/4 turn. I then installed the large locking washer on the axle that secures the inner axle nut. If needed to fit the lock washer onto the nut, it is better to loosen the inner nut slightly than to tighten it.

Rusty Driver
Rusty Driver

Posts: 195

Joined: Mon Sep 04, 2017 6:22 pm

Post Fri Jun 04, 2021 7:15 pm

Re: 1948 KB5 Railway Express

KB5 Passenger Side Rear Brakes


Much of the passenger side prep and assembly was like the drivers side, so the series of photos are some of the highlights. The brakes went together faster and a bit easier than the driver's side, BUT, I ran into another problem. Two steps forward, one step backwards seems to be the theme with this truck.

Pic #01 - I knocked out the nearing races, did a sand blast clean up of the inside of the drum and painted the inside center area to protect it using a high heat aluminum paint.

Pic #02 - The wheel studs are left and right when installing the lug nuts. Passenger side studs are embossed "R".

Pic #03 - Outside of the rear drum. I gave it a light hit with the sand blaster to knock off some of the loose paint/undercoating. Drums are originally painted red. After a thorough cleaning, I painted a coat of black on it. Spent time getting the inner hub grease/grit free clean. Installed the races, grease packed the bearings, and installed the inner bearing felt seal pack to complete the drum and make it ready for installation.

Pic #04 - My brake lining grinder set-up. I added an arrow pointing to the thin 1/4" black marker line I applied to the brake lining. It is faint in the photo, but you can see it. Used this as my guide in grinding down the lining and making the amount of material removed uniform.
Just like the other side, I used my micrometer to measure the brake lining/brake shoe thickness to get my starting point. The thickness measured .636" and I was going to grind the lining down in 3 steps based on the drivers side. My first cut was to bring the measured thickness down to .590", then install the brake shoes on the axle's brake backing plate using only the adjuster pins, and then slip the drum over the shoes to see how it fit. I got the shoes on the backing plate and the drum slid right over the shoes without any binding like the other side. This let me know that the drum was most likely turned at some point and not as thick as the drivers side drum.

Pic #05 - I pulled the drum off the shoes, and proceeded to add all the small parts to secure the shoes to the backing plate.

Pic #06 - The brake shoes are secured into place and ready for the drum.

Pic #07 - This is a "Brake Spoon" used to turn the teeth on the star wheel adjuster when the time comes to adjust the brakes. It is basically a flat piece of steel having the 2 different angled bends to catch the teeth on the star wheel. It is made by Performance Tool, Part No. W80630, and found at most auto parts stores.

Pic #08 - Close-up of the star wheel. The flat bar, which has the shape of a slight "V", sits on top of the wheel and acts as a spring and sets between each of the teeth on the wheel as you rotate the star wheel. This locks the star wheel from rotating anymore than its adjustment. Rotating the star wheel causes the main body, which is threaded, to screw/unscrew from the threaded rod seen attached to the back shoe and expands or contracts the 2 shoes together. As the brake lining/drum wears, the star wheel is turned to expand the shoes outward to bring the required air gap between lining and drum to its factory spec. If the drum or shoes are to be removed, the star wheel is typically turned to retract the shoes making drum removal easier.

Pic #09 - #10 - Here is how the brake spoon works. It passes through a slot at the bottom of the backing plate and makes contact with the star wheel. By moving the tool up or down, it makes contact with the teeth on the star wheel and rotates the adjuster so it expands or retracts depending on what is needed in adjusting the brake shoes. The photos show the use of each end of the brake spoon. Along with the star wheel, the brake shoes are also adjusted using the brake adjuster cams in moving the brakes/linings out towards the brake drum and using a feeler gauge inserted through a slot in the drum to achieve the correct clearance.

Pic #11 - Drum installed. I had to use 2 C-clamps as I did on the driver's side to draw the inner bearing race onto the axle due to its tight interference fit. I installed the outer bearing and then the inner
axle bearing nut - there are 2 nuts used to secure the drum. I tightened the nut tight to seat the bearings, backed it off, tightened again, and then backed it off. I then rotated the drum to ensure it rotated freely with just a slight drag of the brake shoes. I then tightened up the bearing nut just snug enough to cause a slight drag as I rotated the drum - this is where a little experience in brakes comes in handy. BUT, Timken states to tighten the axle nut to 200 ft lbs while rotating the drum/wheel. Back the nut off 1 full turn. Next re-torque nut to 50 ft lbs while rotating the drum/wheel, then back the nut off 1/4 turn. I then installed the large locking washer on the axle that secures the inner axle nut. If needed to fit the lock washer onto the nut, it is better to loosen the inner nut slightly than to tighten it. Next came the outer axle nut having the felt seal. And that's when the next problem was discovered!
Attachments
01 Passenger Side Drum - Inner.JPG
02  Wheel Stud Marking R.JPG
03  Passenger Side Drum - Outer.JPG
04  Grinding Brake Lining..JPG
05  Shoe Installation.JPG
06  Brake Shoes Secured.JPG
07  Brake Spoon.JPG
08  Star Wheel.JPG
09  Brake Spoon.JPG
10  Brake Spoon.JPG
11  Rear Brake Installed.JPG

Rusty Driver
Rusty Driver

Posts: 195

Joined: Mon Sep 04, 2017 6:22 pm

Post Sat Jul 17, 2021 11:44 am

Re: 1948 KB5 Railway Express

Outer Spindle Nut - Cross Threaded Part 1

I got the brakes/drum on the passenger side installed. Screwed on the inner spindle nut which goes on after the bearing is installed. Then I installed the nut's lock washer. I went to install the outer spindle nut having the felt seal and it only went on a couple threads and would go not further. I pulled it off only to see that the threads had been badly damaged.

Pics #1 - 5 Show both the inner and outer spindle nut, a close-up of the outer nut and the circular retainer that holds the felt seal (which appeared to be a separate piece attached to the nut), and some of the dimensions - the width was taken from the inner spindle nut which is the same nut used for the outer nut.

Pics #6 - 7 The inside of the damaged threads on the spindle nut. If you look to the inside of the nut and to the right side of Pic 6, you can see the threads are closed up and taper closer together. Pic 7 is the nut flipped around and the bad threads are now on the left. The threads were a little worse in another area and they had lost their "sharpness" and looked pressed down.

So what happened? I did not notice any problems when removing the nut, but I also did not know/pay attention to look for or see any problem - I just removed the nut in the disassembly process. The nut had been damaged by a previous person. What I determined was that at some point, new bearings had been installed. I learned on the driver's side that the interference fit of the inner wheel bearing was extremely tight and I had to use the C-clamps to draw the bearing fully in on the spindle's machined area. Then when I tightened the inner spindle nut, it drew it in just a bit more.

My guess is that someone installed the new bearings, got the inner bearing on, BUT, did not seat it fully. I did the same process on the passenger side as I did the driver's side. When I went to tighten the inner nut, a process of tightening the nut/rotating the drum several turns to seat the bearings in their races/tighten nut again and repeat, I was able to tighten down the nut several times until it would not longer move and the drum could not be rotated. Then backed off the nut until the drum rotated, re-tighten until the drum stopped moving, then backed off until I could rotate the drum again.

So what does this mean? If the bearings were not seated as I described and the inner spindle nut was not fully drawn down, it would have acted as if it was further out on the spindle threads. This would then put the lock washer further to the outside of the axle, and then when the outer spindle nut was installed next, it would not have been fully tightened/seated on the spindle. When the axle shaft was installed, the outer nut/felt most likely would not allow the axle to fully seat - there was a gap and the 8-nuts that bolt the axle to the drum was not closing the gap. Out comes the sledge hammer to seat the axle. In beating on the axle, it beat against the outer nut, forcing it onto the threaded axle and crushing/damaging the threads on the inside of the nut. Argh!
Attachments
01.JPG
02.JPG
03.JPG
04.JPG
05.JPG
06.JPG
07.JPG

Rusty Driver
Rusty Driver

Posts: 195

Joined: Mon Sep 04, 2017 6:22 pm

Post Sat Jul 17, 2021 12:00 pm

Re: 1948 KB5 Railway Express

Outer Spindle Nut - Cross Threaded -- Part 2

So NAPA didn't have an outer spindle nut for the '48, LOL, so I had to figure my options. 1.) Find another outer nut, 2.) Drive 8-hours to Ohio where my brother has another complete chassis and remove it, 3.) Find a machine shop that could make a new nut (flat) so I could add the felt retainer to it, 4.) Find a shop to re-cut the threads (12 - Threads Per Inch ), 5.) Figure out how I could salvage the threads.

Contacted machine companies with no luck. Purchased a new truck/trailer spindle nut that had similar dimensions but turned out to have too large and OD dimension. Did not want to drive to Ohio and burn up a weekend plus. So salvaging the threads seemed the best solution and seeing this is a backyard mechanic's rebuild, that this would be the way to go and give someone a solution if it happened to them.

I found that there were plenty of tools to restore OD threads on large truck spindles - we have this at my work. But I needed a tool for inside threads for a large sized nut. McMaster-Carr offers a tool to restore internal threads. Looks like a large sized snap ring pliers with assorted dies use to re-cut the threads. I had to buy a separate set of dies having the needed 12 TPI teeth. I received the tool and in no way was it going to work - it was floppy and by design shifted around and you had to use hand pressure to keep the dies in contact with the nut and my threads were just ins such poor shape that this tool was not going to work. But, I got the 12 TPI die set which I did need.

Pics #8-10 Backyard mechanic thinking went into gear and I created a "tool" to hold one 12 TPI die in place while I rotated the nut around it to cut the threads. The problem was I needed some kind of support/guide to hold the nut in place as I rotated it onto and over the die to re-cut the threads. Found that a 2 1/8" hole saw fit pretty good in the inside of the nut. It was not a perfect fit and has slightly smaller in diameter, so I had to position the hole saw in a way that would keep the nut in place and allow me to exert pressure on the die in cutting threads. I had to slot the hole saw so I could get some rotation out of it to put pressure on the spindle nut so as to hold it in place when I began rotating the nut over the die. So I figured all this out, drilled holes, bolted things down, and began the slow and careful process of trying to salvage the threads. I used light oil to help cut the threads and was constantly cleaning the die of metal from the cutting. I worked the nut back and forth just small amounts to cut into the threads and began the nut just as I would on the spindle. Since the threads were better on the front side and damaged on the back side, I started my nut on the good threads and worked into the bad threads. This did take some time, rotating back and forth in small partial turns, clean the die of metal, oil, repeat, and make a little progress as the nut would rotate a little further along. I finally got it to where I could screw the nut over the die just as I would on the spindle. I could feel the nut dragging/catching in some spots as I was never able to get it perfect, but figured good enough.

Pics #11-12 Here is what I ended up with. Better than the damaged threads, but proved not to be perfect as needed. I cleaned the nut up and fitted it on the spindle. It tightened down better and further onto the spindle threads, but would not go completely on - there was still some damage I could not seem to repair and I did a couple trial fits and worked the nut back over the die. No improvements, so went with what I ended up with. My concern was getting the felt seal retainer below the flat flange on the drum in which the axle shaft would bolt to. I put a flat edge onto the flange and I had space between it and the seal retainer - plus a little more with the axle/flange gasket.

The outer spindle nut/felt seal is supposed to be tightened down against the inner nut's locking retainer that keeps the inner nut locked into place and keeps it from rotating/loosening up. I installed the locking retainer and found that I had to back off of the inner nut just slightly to get the retainer's folded locking tab that goes over the flat edge of the nut that holds it from rotating. Never tighten to match the folded tab to the nut as this will over tighten the bearings, just back off the nut enough to get the tab to fit (same as needing to back off the spindle nut on a car to get the cotter pin in place.) With that done, I installed the outer nut and got it tight. Then I wanted to see just how much space I had between the back of the nut and the locking retainer - too much could have the retainer sliding forward and the tab no longer holding the inner nut from rotating. I measured the space to be .030". I did not see a problem as the folded tab was way longer than this and would still catch and do its job. I could have fashioned a circular spacer, but felt it was not really needed seeing this truck will not see delivery service or many miles for the use it will get.

Pic #13 - Next I installed one of the old original felt seals which was in good shape, oiled it, installed my flange gasket with sealer, then inserted the axle shaft, and installed/tightened the 8 retaining bolts. Rotated the drum and it seemed perfect. FINALLY! The pic is the completed driver's side, the passenger side now looks the same. Almost ready to re-install the tires/rims. Both rear brakes/drums/bearings are now completed. Do the brakes work? Guess what? That was my next problem - bleeding brakes and once again, a bad mechanic did not know what he was doing and I ran into my next trouble spot at the brake line junction block. That will be covered in my next segment. Two steps forward, one step backward once again.
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Rusty Driver
Rusty Driver

Posts: 195

Joined: Mon Sep 04, 2017 6:22 pm

Post Sun Aug 15, 2021 7:26 pm

Re: 1948 KB5 Railway Express

Brake Junction Block Repair

My next problem was discovered when I went to install the rear brake line fitting into the brake junction block that feeds off the master cylinder and then sends fluid to the front & rear brakes. The side I was to attach my rear brake line to had a steel hex plug in it. When I got the truck only the front brakes had been worked on and nothing done to the rear brakes, so a plug had been installed to block off the line.

I removed the plug, and did my best to get my rear brake line fitting into the hole - just could not start the threads. I don't use a wrench when starting these threads, always hand tighten first to ensure the fitting is going into the threaded hole. No luck at all. So I pulled off all the brake lines to remove the brake block for further inspection. Like many things on this truck, someone with no mechanical aptitude had been here. The threads in that port were cross-threaded, but the steel plug had no issues biting deep enough to hold and prevent any fluid leaks. Argh!

I first tried to braze a brake line adapter in the hole and then screw my brake line into that. Well, that did not work as planned and the adapter just melted away on me. So where do you find a multi-port brake block? Best I could find having the ports I needed was a 1965 Chrysler, so I ordered it. It cam in and the ports/fluid holes were too small, they were 3/16" and I needed 1/4" - the way brake sizes/threads are measured is a bit confusing to me. So that did not work.

I looked at the brake block and realized it had a port on the other side, but I thought the block was a solid piece and hooking the rear brake line in the other side up against the frame was an option, but meant I would have to change several brake lines and re-bend them to fit. I took another good hard look at the brake block and realized it came apart and was made of a couple pieces.

Pic #1 Shows the brake block disassembled. You can see the plug which was on the frame side. You can also see my fix - I brazed closed the port that had been cross-threaded. Then I rotated the center section so the good port would be positioned on the engine side so I could connect my rear brake line.

Pic #2 Is the brake block center section flipped over, my brazed port, and it now re-assembled. Now it is ready to be re-installed.

Pic #3 Got it installed and all my lines connected as they should be.

Pic #4 I wanted to install a "hold off valve" which is a hot rod item when doing custom brakes and can also be found on some production cars of old. What it does is to keep a small amount of pressure in the brake line after the brake pedal is released. It is 10 pounds and the also sell these in 2 pound valves. It keeps the brakes a little "primed" in that there is already fluid in the line as opposed to fluid in the line completely draining back to the master cylinder.

This one is made by Wildwood, but others make them as well. Again, my problem was line size. These are for smaller brake lines and the orifice for the fluid flow is also much smaller. Basically, this is a check valve. I removed the nylon plug having the smaller hole for the fluid and drilled it carefully oversized - no doubt Wildwood would not recommend this or if it would work. I took my time and drilled the hole oversized and cleaned up all the burrs in the nylon plug. Then installed the plug back into its housing, and used a line adapter that screwed into the hold off valve ends and allowed the 1/4" brake lines to screw into the adapter. I assume it'll work as it is supposed to - didn't get any leaks, so that is a good sign.

I also bought these aluminum/rubber flanged seals from Earl's that are made of aluminum. They replace the copper O-ring seals used in the brake line system - like the banjo fittings. Unfortunately, I only got rhsmaller sizes and the banjo bolts/fittings use both a small and large copper washer seal. These copper washer seals can be touch and go as to whether or not they leak - even using new copper washer seals. You want to tighten them down fairly tight, bit not strip out the banjo bolt and threaded hole. Earls is supposed to work well with the softer aluminum and the rubber seal.

Pic #5 Is the hold-off valve installed. You want this as close to the master cylinder as possible. I installed it where it was convenient and not too far from the master cylinder. I decided not use anything up front as the lines are very short and already close to the master cylinder. I want all the braking power I can get from this old truck and its original brake system.

LESSON LEARNED

Lesson #1 So all my brakes are now done and it is finally time to bleed them and hopefully they work. WRONG! LOL Hear we go again. In trying to bleed the brakes myself, I used one of those hand vacuum pumps which attaches to the bleeder screw, you build up vacuum, crack the bleeder, and the fluid gets sucked out through the line and into a canister that holds the brake fluid. I get brake fluid and air bubbles. I had bled the fonts when I did them and had no air and firm pedal. Now I have air bubbles. I try each side - the same. Then I decided to go to the back brakes - same thing. Now I am thinking my brazing job or one of the lines is not seated at the brake block. So I remove the rear brake line fitting, install the hex plug, and try the fronts again to see if that isolates anything. Nope- still have air bubbles. Hmmm. Had a friend now help me do it the old fashion way of cracking the bleeder, pushing the pedal and hold, close the bleeder, then let up the pedal. No air bubbles. The hand vacuum pump was apparently pulling air past the threads of the long bleeder screw making it seem like there was air in the brake lines. Got a good firm pedal on the front brakes and re-installed the rear brake line into the brake block.

Lesson #2 With my help, I went to bleed the rear brakes. No bubbles/air, but no brake pedal and I was losing fluid somewhere. I checked all my connections on the rear brake lines and all were tight and no leakage anywhere.........except coming out of the bottom of the drum on the driver side. Yep, gotta pull the axle and drum off to inspect. What I found was that the wheel cylinder plunger on the back "leg" of the wheel cylinder had pushed out of the casting and fluid was pushing right past it. The rod that goes into that plunger was not inserted deep enough to keep the plunger from over extending and pushing out the end. How could this be?

When adjusting the brake shoes using the 2 front cams of the front shoe and the top cam of the rear shoe ........ you must adjust the star wheel so as to push out against the brake lever which inturn pushes the lever's rod deeper into the bore of the small wheel cylinder "leg". I had not done this assuming that the lever's rod was where it was supposed to be within the small cup of the wheel cylinder's leg. I should of, and did, push the rod deeper into the "leg" pushing back the cup and plunger and then screw the star wheel out to lengthen it's adjustment which pushes the lever's rod further down the bore of the wheel cylinder "leg."

Once I figured this out, I inspected the wheel cylinder cup, re-inserted it into its bore, and then adjusted the star wheel to take up the slack at the rod. I re-installed the drum/axle and then using the spoon, did a final adjustment of the star wheel by rotating the drum as I adjusted until I could hear/feel drag of the brake shoes/drum. Then went to the passenger side and correctly adjusted it before having another problem on that side.

The Big moment at last. Bled the rear brakes, old school again. No air, no fluid loss. I HAVE BRAKES that work and a solid pedal. Next will be installing the rims/tires, firing up the engine, and seeing if the old gal will move and stop on its own! If not, I am going to donate it to the Army for a target for gunnery practice! LOL
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Golden Jubilee
Golden Jubilee

Posts: 5170

Joined: Thu Nov 29, 2012 9:28 pm

Location: Lyman, IA

Post Mon Aug 16, 2021 8:04 am

Re: 1948 KB5 Railway Express

Looking at the fittings, the need to add a RPC (check in the brake line) , 1/4" line and Hi Tork rear brakes, I'd say that truck had a hydrovac, that someone removed and cobbed it together.
You can say I'm full of it like you normally do, but I have two trucks from this era and a career working on trucks that say otherwise.
The manual does say that a hydrovac was an option on the 5 (unlike the 6 and up, where it was std) but everything points to a missing hydovac.
1st time trying to stop it at road speed will be an eye opener for sure. With the working Hydrovac, I can lock the tires loaded on a K-7, with the vacuum depleted, it is a bear to stop empty.
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