Disc brake conversion tip (AKA don't trust application manuals) [Archive] - Chevelle Tech

: Disc brake conversion tip (AKA don't trust application manuals)


thunderstruck507
Aug 17th, 04, 10:33 PM
Thought I'd post a tip here...

I put a 70 model disc system on my 71. Always had weak brakes...

Parts guy said his book listed a dif master cylinder for both years. Gave me the one for a 70 since it matched the system.

Today I changed it out and discovered the pin length from the booster to the master is different as someone here stated, the pin was moving an inch before ever starting the brakes since contrary to the parts catalog the one I had was a 71 master. Put on the right one and now the car tries to throw me out every time I touch it (i'm used to the excessive travel)

Point is, if doing a conversion between these years please note that the pin on a 71 is longer by about an inch and goes into a recessed hole in the master cylinder. A 70 has a shorter pin and there is only an indention on the piston of the master cylinder the pin has contact with.

gUmBaLL68Malibu
Aug 17th, 04, 11:05 PM
Ran into that same crap with our 64 suburban. The brakes kept going on then off and on ended up being the rod was about 1/4" to long cut it off been working great ever since.