Replacement Chevrolet master cylinder

[Grant Bowker]

Most Wagner master cylinders seem to have a 2 letter prefix, commonly FD or FE. Raybestos markets a replacement for the 9220 as MC9220, Dorman sells as M9220, NAPA as NMC P9220.

[Bob Carriere]

https://www.ebay.com/itm/New-NOS-Del...VX4n0v&vxp=mtr

Yes the bolts are different but the cross section of 1 1/4 is correct.

It is a lot of $$$ just for a core that will be rebuilt....... these 1/4 inch larger Masters were intended for the 1 ton plus trucks.

cheers

another https://www.ebay.com/itm/CHEVROLET-T...xaYSSR&vxp=mtr

another listed for GMC but same part ###https://www.ebay.com/itm/1938-1939-1...VZsqL0&vxp=mtr

[Barry Churcher]

Hanno, I don't know the number right off hand but I probably have the box with the old core in it on a shelf someplace. Any of the cylinders above that the guys have mentioned should work. The cylinder with the new bracket was a fairly easy fab and it worked excellent. You have to make sure the bracket is heavy so as not to flex on application.
Cheers,
Barry

[Hanno Spoelstra]

Great input guys!

This info should give the next one looking for a master brake cylinder replacement enough info to work with. This is the sort of subject where the combined knowledge of MLU members keeps these ageing vehicles running.

Thanks,
Hanno

[Tony Smith]

This M/C is of the correct configuration:

https://www.ebay.com/itm/NOS-1936-19...EAAOSwHMJYFAgk

However, the seller recommends that the correct kit to put through is the #3 kit, which is only a 1" bore. This may be a typo, as the kit for the 1 1/4" bore is a #33 (also known as TM3630). If this is actually a 1" bore, I wonder if it could be bored out to 1 1/4" when sleeving?

[Grant Bowker]

Visually, the ebay master cylinder is consistent with the commonly found 1" size. I believe there was also a 1-1/8" cylinder made.
The NAPA kits 3 and 33 kits look similar in style, so without measurement I wouldn't assume the seller is wrong. The Raybestos kit for the 1" bore is MK3, consistent with the NAPA information in the ebay listing. The Raybestos kit for the 1-1/4" cylinder is MK33 so possibly the NAPA 33 might also be 1-1/4" but this is not confirmed.
I believe the casting number on the 1-1/4" cylinder (ebay listing gives 5450256) ends 61. On checking the 1-1/4" cylinder I have at home awaiting sleeving has 5450261 cast into it.
Personally, I would not be comfortable taking 1/8" all round off the wall of the cylinder without a lot of careful measuring and thinking. Even more so if removing a bit extra to allow for the sleeve.

[Guy Verstrepen]

mss is a look at this site www.chevsofthe40s.com/