Replacement Chevrolet master cylinder

[Bruce Parker (RIP)]

Wagner MC F9220 is the part number for a master cylinder identical to the WW2 Chev type except it has the two horizontal mounting holes cast into the body instead of the flat base with the two studs as per the WW2 type. I hope to sleeve a WW2 original for my HUW but failing that this one goes in. It will require an angle bracket with four holes to adapt the original stud mount to these two horizontal bolts.

I did a quick google search and this number didn't come up so it may be as hard to find as the original however.

[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.