i have a 91 with disc breaks thats not breaking at all. I noticed my rotors were badly rusted when i went to paint and clean my calibers. so i raise the rear put the car in drive and brake, nothing at all. what gives could both calibers be bad(stuck), pads are good kinda gunky, car was a wisconsin car so im currently dealing with rust issues could the calibers be another, im a bit weary of paying 100 bucks per caliber to replace before asking need some input thanks

 

Did you try bleeding them?

 

No I didn't but i am doing an ls1 brake swap this weekend so changing fluids is on the to do list, how will bleeding help, work pls. explain

 

Have you looked into the rear calipers at all yet, meaning have you removed the wheel and physically looked at them? Here's my suggestions.

If the rear hoses have never been replaced, start there. Odds are they have rotted from the inside and are plugged, allowing no fluid to get to the pistons. Second, while replacing the hoses, remove the calipers and see if they slide freely in the guide pins in the abutments. If not, pull the pins, clean the pin bore in the abutment, grease them up and install new guide pin seals. Also, push the caliper pistons all the way in and make sure they slide freely and don't bind. If they do, either rebuild them or replace them with new/rebuilt ones. Maintenance fellas, maintenance.

Ed

 

if theres an air bubble in the rear lines then u would loose brake pedal/PSI to the rear calipers. the rear and front brakes are totally independent of eachother. bleeding would be the best start. i doubt both calipers are bad but then again these cars arent so young anymore. if your doing a LS1 brake swap i would just do the entire brake package.

SSBC sells a brake pressure gauge kit that uattach to the calipers and it tells u the PSI of each caliper. if u test them and the guage reads less than 600psi i would say u got a prob wit the calipers if u bled the brakes already etc. could also be the proportioning valve or a clogged line.

bleed them and see. post wat u find out

 

JamesC

 

Thanks for all the help guys, i will replace the brake lines tomorrow, something tells me they are rotted or plugged, (one of my fuel lines was so rotted it had a leak) i've taken the calibers off and did notice they were dry, yet gunky but replacing the brake lines sounds like a good idea where can pick them up as a complete kit, is that available thanks 4 the help will come back as soon as i bleed and change the lines with an update(hope that works)

 

The rubber OE lines can be had at the auto stores. For braided lines, you might check Spohn.

JamesC

 

I picked up a 91 posi-disc in MI., where salt & corrosion abound, so a
complete rebuild was in order. One guide-pin on each bracket was rusted
to virtual seizure. Was able to get one out with selective heating, had
to drill out the other. As for the calipers, (which were also rusted to
immobilility), I couldn't find any re-build kits. The only option was complete
replacement, and about $90 per copy.

And if you want to replace the main flex hose from the chassis to the
T-fitting, there isn't a listing for the disc-brake option, but the standard
drum brake line fits correctly.

Good luck.
kk

 

Bought mine at O'Rielly's.

JamesC

 

Well butter my butt, & call me a biscuit.

Unfortunately, I was in Grand Rapids MI. at the time, and there
weren't any O'Reilly's. Was kinda suspicious, but the parts house
I was using was doing other things right by me, and its what I
needed at the time. When I left, there weren't many remaining to keep
the lights on...

 

FYI all rear center lines will be the same regardless of rear disc or drum.

Ed