Rusty Driver
Posts: 195
Joined: Mon Sep 04, 2017 6:22 pm
Re: 1948 KB5 Railway Express
Pulled apart the rear brakes. I bought a 4-ton jack for the job as my 1 1/2-ton car jack had to struggle way too much to get the truck lifted. I got the truck up in the air easily with the 4-ton jack and blocked it up using solid (not hollow) cement blocks under the rear bumper.
Pic #1 & #2 - The truck has dual wheels, so first removed the outer wheel nuts & wheel, then the inner Budd type lug nuts (using a special Budd type socket) which secures the inside wheel and then removed wheel. Drivers side is left handed threads, so loosen by turning to the right. The drum is now accessible. The rear axles get pulled next by unbolting the nuts that hold it to the Budd drum.
Pic #3 - Next is the axle lock nut - this is the one on the outside (there are 2 axle nuts). This nut also has a channel machined into the outside of it that holds a felt seal which rests up against the inside of the axle flange to keep gear oil from spilling out of the axle tube and onto the brakes. The outer lock nut is secured by a flat like washer that has "ears" which are folded over onto the lock nut to keep it from backing off. Look for them as they are there. Flatten or break off the ears with a small chisel and remove the outer lock nut. I learned that the axle nuts unscrew as any nut does, and were not left handed threads like the lug nuts. Slide out the securing washer and remove the inner axle nut which holds the bearings/drum in place. Then the drum/bearings are free to be pulled off.
Pic #4 - Upon removal of the driver's side brake drum, the front brake shoe was in three pieces. The problem here is that the brake shoes are cast iron with the brake lining riveted on. Good luck on finding a "new", let alone good used, set of brake shoes. As old as these are, I don't trust the cast iron. My guess is the brake shoe was at some point frozen to the adjustment pin at the bottom and when the brake was applied, the pressure from the wheel cylinder was great enough to bust the cast iron. More on this later in another post.
Pic #5 - Everything was frozen up from sitting so long. The "Hi-Tork" wheel cylinders, sometimes called "mountain brakes," were frozen solid and the aluminum pistons corroded away in some spots. Thought about having them sleeved and rebuilt, but when I broke one of the cylinders trying to free up the piston inside, I purchased a new reproduction set from an Ebay seller. The reproductions are a match & complete. They come with attachment bolts and lock washers, copper O-ring gaskets & banjo screw for the factory banjo brake cylinder fitting that gets reused.
Pic #6 shows the lower section of the brakes with the screw expander which pushes off the front shoe to adjust the bottom of the rear shoe. The lower section of the front shoe uses a cam adjuster seen to the left of the screw expander and moves the shoe in or out to get the correct air gap between the shoe lining and drum. The screw expander has a star wheel like most drum brakes, but this one is broken in half and can be seen jammed at the top of the screw expander. I'll fabricate a new one.
Pic #7 & #8 - Got all the brakes apart & off. You can see the three brake shoe adjusting cams, 2- round and the 1-triangle. These get removed, freed up, and reinstalled. With everything disassembled, I cleaned up the backing plates and painted them. Then I installed the new Hi-Tork wheel cylinders. I painted them to protect and used a silver paint so they would show up better in my photos.
Pic #9 - I wanted to change the rear axle gear oil and at the same time, look inside at the gears to check their condition. I removed the steel brake lines and the rubber brake hose attached to the rear axle cover. Drained the rear end gear oil and unbolted the cover and removed it. No metal of any kind found in the bottom of the case and everything looked good inside. I stripped the rear end cover to bare metal and repainted.
I did not have, nor used or made, a cork gasket for the rear cover. Instead I went with Permatex RTV Gear Oil Gasket Maker, #81182. It is supposed to be specifically used on transmissions and rear axles having gear oil. I cleaned both mating surfaces, put a bead on the rear end housing and a thin layer on the cover. Then bolted it together getting the bolts snug enough to watch the RTV squeeze out along the edge cover. It says to let it set like this for 24 hours, then torque down the bolts.
The original steel brake lines were rotted and the rubber brake hose shot. The hose itself measured about 17" having a female end at the frame which was attached to a bracket on the frame and a male end that went into a brass "T" block which then bolted onto the rear end cover. The left & right steel brake lines on the rear end screw into the block. Total length from fitting to bracket was just a little over 19".
Rather than locate another straight hose, and to eliminate a potential leak using the original "T" block, I found that a 1971-72 Chevy Suburban rear axle hose was 18" long and had the brake line fitting for the steel lines as part of the hose. The Suburban hose uses a horseshoe clip to hold it in place on its frame, while the International hose had a threaded end and used a large nut holding it to the bracket bolted to the frame rail. I removed the horseshoe clip from the Suburban hose, did a little grinding to reshape the hose end so it would pass through the International bracket, and then reinstalled the horseshoe clip to secure.
The bolt hole on the Suburban's T-fitting end which secures the hose to the rear end cover was smaller than the original International bolt hole on the "T" block. The Suburban fitting did not have enough material to drill oversize, so I fabricated a short length of 1/8" flat stock having a small hole on one end to bolt up to the hose and a larger hole to pass the bolt through used on the International's rear end cover. I removed the top left rear end cover bolt and attached the bracket with brake hose at that point.
Pic #10 - I torqued all my bolts to 40 ft lbs. I could not find any torque numbers for this. 30 seemed not enough, so I went with 40 ft lbs. The top left bolt on the rear end cover has a hole drilled through it and makes up the rear end breather. It was plugged up at the outgoing steel cap. I pulled the steel cap off and added a breather tube using 1/4" brake line bent 90 degrees downward and a joining section of rubber gas line hose and hose clamps.
I purchased two 4-foot lengths of steel 1/4" brake line to make the rear axle brake lines. I formed each line around the cover and out to the backing plate and into the banjo brake fittings that screw into the wheel cylinders. I reused the factory clips attached to the rear leaf springs to run the lines through and had to fashion another length of 1/8" flat stock to create a bracket to hold the brake line secure from vibration/movement on the right side. I cut to length & flared each brake line once I had the correct length of line going up and into the banjo fitting. Not factory perfect, but pretty good in my book while laying on your back in the dirt.