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!980 Fleetwood Master Cylinder Upgrade Question

1079 Views 3 Replies 2 Participants Last post by  the APEMAN
Soooo my '80 2 door Fleetwood needs a new master cylinder. You'd think GM could make stuff that lasts more than 33 years:crying2:

The existing looks like the typical cast iron type.

I remember the 77-79 Cadillacs used to have poor pedal feel with the caliper pistons retracting and taking some pedal displacement before the front brakes would do anything.

I also remember being able to swap the entire brake booster and master cylinder from an 81 through 85 RWD Cadillac to give excellent pedal feel. The newer aluminum/plastic master cylinders were designed to initially displace more fluid to the front brakes.

I would like to swap one of the newer master cylinders into my 1980. My booster is still OK. What I need to know is will it work with the existing booster and lines between the proportioning valve and master cylinder.

Performed this swap 3 times and I cannot remember what I used to do. Been out of auto repair for pay for 20 years.

Does anyone know? T.I.A.
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I'd be guessing but I think as long as you have rear drums like the 81 donner car you will be good.. I'm thinking if you got rear discs the 81 won't work right because I don't think it came with disc rear as a option... When I got my 78 disc -posi rear, I took the master cylinder and porporting valve.. But I never used them. I just put the drums on it and kept the 81 stuff...
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