wheel cylinders for 5 ton GMC

My 1976 GMC livestock truck has 72000 miles on it, and the wheel cylinders are weeping, The garage man said they have to be replaced to pass safety inspection but they are now an obsolete part. Anyone have any ideas as to were I might find a set so this old girl can get back to work. Or any kind of updated parts that could be used as a substitute. All good suggestions will be greatly appreciated.

I am not familiar with the large trucks... what cylinder is weeping? Is it something that could be torn apart and seals made? Or can you find another (possibly newer) whole axle?

If the bores are pitted it maybe possible to sleeve them back to true.

sounds to me that it time to go to a good parts house. I avoid the ones that have no only kids working behind the counter. The older staff seems to have a better grasp of reality when it comes to finding obscure parts.
tim in OR

They are probably obsolete from GM, but may still be available from NAPA. And there are specialty houses that just deal with brake parts. One I can think of in Minnesota is Brake and Equipment Specialty Inc. But I just hit Google and found about 600,000 hits from "heavy truck brakes parts". I doubt the parts you need are all that rare, just inconvenient to find.

If all else fails, the restoration car and truck people have machine shops listed that will bore and sleeve your existing wheel cylinders, but that will probably cost more than finding new ones.

There are still a lot of these old trucks used on the farms, and the parts market is supplied by many shops and small manufacturers. Often the big companies just want to deal in the high volume relatively new stuff.

Good Luck in finding what you need.

Paul in MN

Do a search for White Post Restorations, they can sleeve them.

You can most likely rebuild them yourself, get a kit and hone out the cylinder clean it up good and put it back together, I do it all the time

i got two last year and they said them were the last two

marlowe, you really know how to hurt a guy.

What brand of brakes do you have? Most of the older GM trucks had Wagner brakes. All Wagner brake parts are available from NAPA or other large parts stores. There is a CATCO store near me in Rochester MN. They have a large catalog of hydraulic brake parts. They have rebuilt master cylinders, boosters, shoes, drums, cylinders, adjusting and spring kits, almost everything for GM trucks. What does your truck have for brakes? I have a CATCO hydraulic catalog.

sorry but we tried Napa and all

I don't know what kind of hydraulic brakes these are , and I am not doing the job my self. But I certainly appreciate the Leads/good ideas as to were to look next. The shop that has the truck in for the safety check is going to hone the wheel cylinders and replace the seals. The info you have all shared with me should at the very least keep the garage man from trying to screw me . Would hate to have to change the cab and chassis out from under this rack for something as simple as a few break parts. Thanks all.

GM trucks are pretty good for obsolete parts. We had a '72 C50 that needed rear axle work. The pinion nut is NLA. It was reuse the one we had with locktite or have a custom one made.

Just start calling the local truck parts suppliers... I'd wager to guess that your shop just doesn't want to work on the old relic and I can't say that I blame them really.

I don't know what your situation is... but it might be worth your while to ask yourself if you wouldn't be better off finding a later 90's S-Line International or something similar with AIR brakes, then change your body over.
There's too many people damn near died in those old trucks with hydraulic brakes. Personally I wouldn't want to even go near one anymore.

Since you're in Canada... if you do fix it, try Traction or Parts For Trucks. Probably the best places up here for that stuff. Traction is the Canadian heavy truck division of NAPA... so going to a NAPA around here won't net you much of anything but automotive parts... Not sure if Parts... is as far west as you or not either.

Rod

Well Rod air brakes can have there issues too , and with a farm truck that might sit for a week or two between trips, it can sometimes be a pain in winter with condensation freezing in the system. Not so much for commercial truckers that run every day with driers ect. I am not a pro trucker, just want to take cows to the sales barn , cattle to the ranch and farm to farm travel and have run juice brakes for over 30 years , never had a collision or a misshape. Always keep things in good repair and safety inspection both my GMC and my Ford F800 flat bed hay hauler. All the cars on the road run juice brakes , and maybe Toyota should offer an optional parachute for them run away b@tchs they build. Just a thought

The only time I've ever had moisture/freezing problems with a truck's air system is when the dryer is disconnected...
The problems that air systems have to me is irrelevant when viewed in the context of the number of single axle trucks that have been written off because they blew a line or the hydrovac quit working, etc.
At least if you lose air... the Maxi's are going to apply.
The truck can sit here for weeks at a time too... worst problem is the shoes rusting to the drum a little bit... I just release them and back up a touch. They break loose.

I know a guy that nearly died when he jumped from a runaway Ford F700 about a year ago. A line busted on him near the top of the mountain... and he figuered IF he could ride it out to the bottom he'd either land in the lake or T-bone a car at the intersection... so he cut the wheel and headed the truck into the guardrail as he jumped at 60 K.

Lines blow on cars too. They don't use juice brakes because they're good. They use them because they're cheap and they're simple for everyday joe to understand... because there's ~nothing~ to understand.
You may like them, and I wish you well... but I think you're waiting for a day to die. I sure hope not.

Rod