Hey yall...

next weekend i'm going to Canada to pick up a LSD/Disc rear w/ new rotors (front and rear) calipers, and pads.

i have SS brake lines for an SA w/ 81-85 Disc Rear installed. (fronts installed, rears are waiting)

the car is a 1980 w/ drum rear...

i'm sure i need to do SOMETHING w/ my master cylinder, but i dont know what the hell i need. Please inform me, and/or if you have the part i need (i'm guessing just the proportioning valve specific to disc/disc) please let me know what you want for it.

at the same time i'm also going to be throwing in a 5spd to replace my 4spd... just FYI. I wish i had a clutch to throw in that wasnt in as bad shape as mine, hate to drop a tranny twice...

 

I did another swap on a SA last week. I used everthing from a 85 GSL except for the brake booster as the FB's brake booster is larger than a SA. It was cheaper for us to do it that way than to get a custom brake line (front brake caliper and the main rear brake line (between the hard line and the rear end).

Other than the thread pitch and the mechanical aspect, the SA's front brake hard line is shorter than the FB. the FB has a brake line mount located inside the fender walls while the SA's is in the engine compartment.

Prior to R&R, the night before, be sure to spray WD40 or something similar on all brake line fittings including the nuts and bolts. It will make your job easier.

Good luck to ya.

 

ok i was told to change somethig in the master when i did the swap.

Look on the master cylinder, wherer the rear line comes off there should be a 17mm nut which has the hard line tapped into it. Remove the line and take off the 17mm nut. inside there should be a washer and a spring.. take them out and put it all back together.


Now thats what i was told but i cant remove the nut on my master... looks like its corroded on or something...

well give it a try... its supposed to do something regarding the release of pressure for the breaks

-James

 

Thats the proportioning valve...You can either keep the orig or use the FB's. Either way, I never seen a problem.

 

so thats all i need to do? so i can use the SA prop valve if i take out that spring and whatnot.

if so, thats damn sweet.

 

Expect to no longer have a useful handbrake.

 

que?

 

Disc brake type handbrakes universally suck. Discs don't have the static holding power that drums do.

 

oh, i thought you meant other than that... i figured on that, but wasnt sure, i like the rear discs that have a min drum handbrake inside the rotor... those are cool (my volvo has them, for example).

 

That's the only way to fly.

 

so any confirmation on the prop valve question?

 

dont even bother touching the SA's proportioning valve. just leave it alone.

 

Proportionaing valve: Up to you. I, personally, change them because I am paranoid and assume any problem will arise at a point where my life is at stake; not just tooling around town. However, I just checked the parts microfische and, at least from 81-83, the drum and disc proportioning valve part numbers were the same.

E-brakes: whoever said they suck apparantly did something wrong, as mine have always shown improvement, including the swap I did last weekend. The trick is to get one of the notches over the brake pad pin, as the e-brake rotates the cylinder to wedge the pad against the rotor...at least that's how I understand it to work. Also, if you don't align the pin and one of the notches, the cylinder will push only on the pin, causing very uneven wear of the pad and rotor. One other tip is that the longer of the two e-brake cables goes on the driver's (left) side.

Other notes: 81-82 pumpkins have the early companion flange pattern while the 83-85 pumpkins have the later companion flange pattern. Seems strange that they would change it in 83 and carry it forward, when the axle size change didn't come until 84. Anyway, the 81-82 LSD/disc rear ends require a 79-82 driveshaft and the 83+ rear ends require an 83+ driveshaft. Also note that the earlier "small axles" rear ends are actually stronger than the later "big axle" rear ends because the earlier housing is beefier. Not a big deal unless you are drag racing or running a turbo setup. You can also reinforce the housings, if necessary.

That's all I can think of...