The Stovebolt Site Forums The Parking Lot Big Bolts Advice/help needed on 1956 GMC 450 Master Cylinder replacement

Hello!

We're working on a 56 GMC 450 truck and have run into a problem.

We've exhausted all local resources for replacement of an inoperable Master Cylinder.

The casting number is: 5455375
Bore is 1 and 1/2 inches.
Wagner part number is: F23870

Would anyone know of either a source for a replacement, or a reputable rebuilder for the core we have? -Actually, we don't like the idea of shipping our core off....and hoping it doesn't get lost....so we would MUCH prefer to purchase a functional replacement!

Thanks in advance for any assistance!!!!

Here is a copy of what I wrote in response to a similar question not very long ago.

If you ever can't get new cylinders, or just want some to last forever, have the old ones stainless steel sleeved. DON'T mess with brass sleeves.

The guy to have stainless sleeve your cylinders is:
Mark "the machinist" Frappier
82 Mountianview St.
Agawam, MA 01001
413-789-4588, or 800-528-5235

You send him your bare, stripped, clean cylinders, and he sends them back with a perfect looking stainless insert.
You will still need to go to NAPA and get rebuild kits, or perhaps Jim Carter sells kits?

Grigg

I don't have any experience with sleeved brake cylinders. Why do you say not to use the brass sleeves?

One of the guys I work with just installed a brass sleeved master cylinder in his Lotus and I'm wondering what terrible mistake he has made. I mean aside from owning a Lotus...

I worked with 3 guys who each worked several years at a restoration shop who specialized in installing brass sleeves. None of the three had anything good to say about the results. They not only saw many failed cylinders returned, but had to use brass sleeved cylinders on the restorations they were involved with, and have experienced the problems first hand.

The problems were:
leaking cylinders.
Sticking cups, causing brakes that don't engage and cars that run in to things. for some reason the seals will sometimes want to stick to the brass.
corroded cylinders.
Cylinders that wear prematurely, as the brass is soft.

The same guys now use Mark, mentioned above, and have never had a problem with any of his cylinders. I have seen about a dozen cylinders he installed sleeves in, and I am very impressed with his workmanship, I am also a machinist.

Grigg

Hy SandyL and guys, my catalog shows raybestos part number MC13066, at RockAuto.com $208.79 Napa part number UP13066 $274.00 . Does your master cylinder incorporate a pedal shaft mount, if it does then this is not the right master cylinder, if it doesn't then I think this is the one your looking for, hope that helps.

Thanks for the information!

Our MC has the pedal shaft mount.

The only thing we could find from NAPA had a 1 and 1/4 inch bore, ours is 1 and 1/2. They don't have a source for a repair kit either. We'll try that part number (thanks 3B!) first thing in the morning. "Hopefully", it's one they/we didn't find!

Wagner says the part is no longer available and they no longer produce a repair kit.

We had four VERY helpful shops (2 parts stores and 2 heavy truck brake shops) trying to find something for us and all came up empty. We'd certainly consider having ours sleeved, but without a source for the repair kit......"??"

Thanks Again!!!

Oops!.....while typing, I forgot you'd added the "....if it does then this is not the right master cylinder" 3B.

Your time and attempt is certainly appreciated!

Have you posted at http://oldgmctrucks.infopop.cc/eve
?
They may be able to help you find a kit.

Hy SandyL and guys, I think I found a kit number at least, Napa part number UP148 $26.49, I didn't check RockAuto.com, hope that helps.

Hy SandyL, I sent you a private "E" mail through the sight, it has updated information.

Hey Sandy, it's Andy in Lake George. I'm curious how you made out at Napa... I have the same master cylinder in Ken's 4100. Had a few laughs listening to Ken's story about hauling your truck!!

Andy

in the past i have have many master and wheel cylinders sleeved with brass and never had any problems. the reason they used brass was it was "more machineable" than the stainless steel. if i could have found someone to do the stainless instead of brass that would have been my first choice. kinda seperates the men from the boys in my opinion.

We're awaiting word from NAPA whether the VERY few kits listed nationwide are actually available or simply inventory errors.

Thanks to 3B, we've got some hope "if" we need to sleeve the core we have!

Still no sign of a NOS or rebuilt unit, but at least there's still a few places left to look.

Andy.....wait 'til you see the pictures!

Thanks to the kind assistance provided, we have just gotten our freshly sleeved Master Cylinder back from Mark "the machinist" Frappier!

Using NAPA kit #209, it appears to be good as....or better....than new!

I have to add, we sent the cylinder to Mark on Friday, we got it back on Wednesday. Given the work he did, I cannot praise his efforts enough.

Thanks Again!!!!

Glad to hear it,
I thought you would be pleased with Mark's work.
Can't think of a better way to refurbish a cylinder than with a stainless sleeve, can you?

Grigg

Hy SandyL and guys, Great news, keep up the process.