OldIHC

I need to rebuild mine or if someone knows anyone where I could send the have them rebuilt. I ordered 4 from NAPA after looking at this site and getting the numbers. The front ones were right however the rear ones are not correct. The bolt holes do not match and the ones I received were made for shoes with a ball type end VS the spade type my shoes are. I would even try to rebuild these myself if I had the correct kit.
Any help or guidance is appreciated.
Thanks.

Are the rear brake cylinders you have seized? If you can push the pistons out, it easy enough to measure the bore and buy new cups. The bores should be smooth so the new soft cups do not get destroyed on any old corrosion. If the corrosion is only surface and not pitted, it may be possible to use a hone and clean the bores up. If the corrosion damage is more than surface light corrosion, any machine shop should be able to resurface the bore. I have seen rare wheel cylinders bored and have liners pressed in.
The rubber like cups should fit the bore without being forced in. the metal pistons do not have to fit tightly. The metal piston is only a backer for the soft cup. The metal pistons are not in contact with the pressurised brake-fluid.
Make sure you install the cups in the correct direction. The cups should face into the bores. Many amateur brake jobs fail because of the person getting this step wrong. The pressure of the brake fluid will push on the cups and force them against the bore. This is when the cups will be destroyed instantly if the bore is not smooth.
I like to use a silicone dielectric grease on the bores to ease the installation of the cups. https://canada.newark.com/dowsil-former ... dp/25C3470
Shop around for DC4. The price for a small tube will vary from about $7.00 to nearly $100.00. Caveat emptor.
The silicone DC4 grease will not combine with any brake fluid and become a problem. DC4 resists moisture and should last for decades. DC4 will not damage the new cups.
Resist the urge to do the stupid thing and shake the container of brake fluid. This action will introduce air bubbles into the brake fluid and the brakes will feel spongy. Silicone brake fluid, in the can, can take days for the bubbles to rise and leave the fluid. Regular brake fluid can take up to four hours. This is at room temperature.
You must get this right. If you fail and your truck causes damage or death, your insurance company will dump you in a second. You will be responsible for any and all damages. The small print in any insurance contract requires work and maintenance to be done correctly.

Thanks nikkinutshop. I fully intend to do this correctly so I have brakes. Yes they are the rear cylinders. I have a feeling from looking at what I have these are probably pitted. I cannot get anything to move any direction. I will look closer at them and try to get them apart to see what they look inside.
Again thanks for your help.

If you decide to use compressed air to tease the pistons out, do so with extreme caution. If and when the pistons exit the cylinders they can have enough force to cause serious injury. One simple precaution you can use it to contain the cylinder in a cloth bag. If and when the piston exits, it will be easier to find.

what size is your truck?

I believe he has a KB 2
Or just buy it all new from Speedway Motors.
Front
https://www.speedwaymotors.com/1939-48- ... 91065422-L
Rear
https://www.speedwaymotors.com/1939-194 ... 91065415-R
New drums
https://www.amazon.com/Raybestos-2316R- ... d=15887957 38&sr=8-1

I have all this in my truck. Fits just like originals.
Just save your pads to get re-lined or try these:(these look the part, but have not confirmed, mine were re-lined and matched to drums) https://www.finditparts.com/products/17 ... 201407(BSC)&utm_term=4580496721928872&utm_content=All%20Products

Here's an interesting way to free up the cylinders.
https://youtu.be/DAEkJvXI1nM?t=456

Video is not great

These wheel cylinders have 2 different sizes one end is an inch the other is 1.25 stamped right in the metal. I went to NAPA this morning and their pictures on the screen was not good enough to convince me to get the coming. Just did not look like they would fit. I looked in Hemmings last night and found some folks that will rebuild mine have not called them to what they charge.

Speedway Motors, IHC used same ones as Ford, 1939 Ford ones are stainless sleeved, brand new $50 each, bolt right in, only difference is you have to slightly bend steel line in rear ones to go into cylinder at a slight angle rather than straight in,

order and have them in a week, see above post for links,

no screwing around trying to rebuild most likely too pitted to kit originals,