1970 Polara Power Disc Brake Master Cylinder 2225621


Nov 2, 2014
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God's Country
Just wondering if anyone can assist me in verifying the authentic look as well as casting number of the original assembly line power disc brake master cylinder? I know what a 1970 E Body 2229171 casting number power disc brake master cylinder looks like, but it is round in the front and has the thermostat looking outline on the front of this rounded end. The 1970 Polara C Bodies I have seen with power disc brakes have a similar look to the master cylinder but are rounded towards the firewall. Is the rounded towards the power booster or firewall the correct look for 1970 power disc brake Polaras? I think the casting number on the bottom of the 1970 power disc brake master cylinder should be 2225621 but am not 100% sure. Thanks!!!!!


Well-Known Member
Mar 10, 2020
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Pittsburgh, PA
By coincidence I'm rebuilding a couple of 2225621 castings right now but they are for B-bodies. There are at least 3 different applications that used this casting but they have internal differences and are supposedly not interchangeable despite looking identical externally. The correct part # for '70 C is 2883089. Original casting 2225621 are usually very pricey as they were used on 68-69 hemi cars. Believe the B varieties are reproduced but there are differences with the original; repros (Chinese) don't say Bendix and have a machined divot in the nose, the originals also appear to have a higher quality casting.
You can read some more info here-
I was messing with some Ford stuff and found out that they used a similar Bendix MC around the same time frame & the lids are identical. The mopar lid (2881511) is not reproduced & is expensive but is the same as Scott Drake C7AZ-2162-B (repro Ford stuff) & can be had for about $15.

Here's a 2225621 casting in a B-body of mine. This is an old rebuilt unit I put in years ago & the cover isn't correct. Rebuilt stuff hasn't been around for a long time.
MC booster 3 temp.JPG

NOS 2881511 lid-
NOS MC cover 2881511.jpg
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