The Stovebolt Site Forums The Shop Area General Truck Talk Master Cylinders

Anybody have recommendations for a 52 1/2 ton master brake cylinder? Seems to be plenty available at parts house and on internet. Mine is not rebuildable.

You probably should go for a dual reservoir MC, new lines.

Yours can be sleeved and then rebuilt if that's the way you want to go...

Search White Post Restorations.

Mike B

Check out Brothers Truck parts videos on brake conversion!

I bought a new replacement from RockAuto. I was pleasantly surprised when I saw "USA" in the casting. It was a Raybestos brand.

My replacement was quite expensive but it looks like a cheap ugly POS with a plastic lid. For a few dollars more, in hindsight I should have had the original resleeved. Nobody is looking under my truck, but I know and it bugs me.

Thanks, that is the same thought and concern I have. Will disassemble mine and check bore to see if I can hone it out for a rebuild. If not I will probably go with Raybestos. Again, thanks everyone.

It's been a while since I've been into one of the frame-mounted master cylinders, but I believe they're bored straight through, with threaded plugs on both ends. If so, building a machining jig to bore and sleeve one shouldn't be terribly difficult. If anybody has replaced one recently, I'd be interested in obtaining the old one to experiment on. Drop me a PM if that's something somebody could provide.
Thanks!
Jerry

I bought one from lmctruck.com just 3 months ago. I am very happy with it. They have new and remanufactured. I bought the new one for $75.

Stove I hate those plastic lids,once it sticks your done !!

Classic Industries has a new one for $89, shows a metal cap. Considering it.

I converted using a dual reservoir with new lines and cylinders. With 4 drum brakes I searched one with the similar application. This model had the bolt on lid which allowed me to install a lid with the fittings to pump fluid into the system. I feel better with this system and gives good braking. Doesn't have power assist but it stops when I need to

https://www.brakepartsinc.com/raybestos/catalog-part-search.html?PartNumber=MC36233

I just bought a new Raybestos MC. It's made in China. Hopefully it will be OK.

Dual reservoir MC doesn't help when it's the MC itself that fails.

Generally the two reservoirs are on different circuits. The theory is that if one fails, you will still have brakes on the other one (either front or back). Half the brakes is better than none of the brakes.

I wonder how many people have actually experienced a brake faiulure of any kind with a two-chamber MC? (I have, BTW) It's an event that definitely increases one's pucker factor, no matter which end of the system fails! It's true that "a little brake is better than none"- - - -but until it actually happens, few people know what to expect. The only setup that actually provides a somewhat "normal" stop is the "dual diagonal" system where one rear brake and one front are plumbed to each chamber of the MC. That one takes some extremely sophisticated engineering and plumbing.
Jerry

My dual MC failed in the driveway so it was OK. There is a long steep hill leading to a coffee shop we regularly visit. If the MC had failed on that hill, we could have had a serious accident.

When it failed there was no warning - pedal went to the floor - no brakes - front or rear. After the new MC was installed the brake warning light was one since the rear brakes were bled first. It went out after a couple of hard stops.

A long time ago, we had the rear brake line rust out. In that case, the dual MC worked as expected. The brake warning light came on but the truck could still be driven until the line was replaced.

Dual MCs would provide safety, but I think they are only found in race cars.