Horrible braking performance 92 Cutlass Supreme

[Guest donkeykongrape]

Well first off, I've heard many stories about the brakes on my line of cars being poorly designed and such, and I already read the article on this site about the rear calipers seizing up, however I still have a few questions.

 

I recently replaced all the pads on my car, and even though I still have terrible braking performance, I notice after a while of driving, the front pads give off a strong burning odor and my braking performance worsens even more. The rear brakes dont seem to do this (this sort of gives me the hint that the rear brakes arent working very well and the front brakes do all the work and overheat, just like the article says)

 

However when I drive slow, maybe 15-20 mph and I slam on the brakes, the rear brakes actually do lock up (sometimes)! This shows that the rear calipers arent completely seized up, and they seem to work slightly...however, when I'm going faster, say 50mph, and I jam on the brakes, none of the wheels lock up and it's really scary how bad the braking performance is.

 

I was thinking of going and buying a set of new rear calipers but I'm not sure if that would solve anything since my current rears seem to already be working. What should I do to improve my stopping distance and stop the front brakes from burning?!

 

Thanks a lot

 

PS: This is my first post and I just recently found this site...it's great!

[joey b]

just because your rears lock up does not mean that they are working properly. Often a caliper going from zero to full breaking is a sign of caliper failure. You might try putting antiseize on the sliders and around the piston where it slides into the caliper. In 94 the rear brakes were redesigned to be better. You could swap that set in, or get a set of 96+ fronts and replace the front assembly.

[Guest donkeykongrape]

Sure, can you please clarify what a slider is and where i should put the antiseize?

 

Where can I pick up a set of rear 94 calipers, and would they fit on my car? Why would I need 96+ front calipers? Are they also better than the ones I have in the front? Can I reuse the pads I have now, as I just spent like 60 bucks on them?

[Crazy K]

I completely agree.

 

Forget replacing the I'm a strong advocate of upgrading the brakes. How to.

http://www.tpsgarage.com/TGP/brakes/rear_brake_upgrade.htm

 

If you can change a caliper and know how to bleed brakes, this upgrade will be a relative cakewalk. I recommend it. I've done it to two of my cars and the difference is night and day.

All the hardware I used was acquired from junk cars that had recent brake jobs done... But that does take a little bit of searching, and a junkyard that will sell you such parts.

 

remember to do the parking brake cable upgrade as well!

[Guest donkeykongrape]

Crazy K, So I can get by with only upgrading the rear calipers and not the fronts? is the difference noticeable? Because I don't feel very safe in the condition it's in right now

[Crazy K]

Crazy K, So I can get by with only upgrading the rear calipers and not the fronts? is the difference noticeable? Because I don't feel very safe in the condition it's in right now

 

Yes you can.

Although Many think the front upgrade is beneficial as well, I don't think it makes that significant a difference. It is the same pad and caliper on a slightly larger rotors, and require a total strut swap. I would only do it if I got a real good deal on a set from a junkyard, and they would have to be a matched set out of a good car.

The most bang for your buck will be by upgrading the rear. simple to bolt in, the hardest part is re-working the cable....

 

p.s. Sometimes you need to replace the rear hoses when you upgrade because the originals might kink if attached to the new calipers. Don't forget to replace any brake hoses you see that have cracks or kinks. And the new brakes have a much better parking brake that will stop the car, whether you upgrade the pedal or not.

[Guest donkeykongrape]

ok, and I can't buy the 94+ rear calipers at any store, I would need to find those at a junkyard too???

 

 

I'm thinking of just servicing my current ones, as joeyb, and this site suggests: http://www.tpsgarage.com/TGP/brakes/servicing_rear.htm

[SigEpCutlass]

if you are already having trouble, I wouldn't get them from the JY. You may be causing yourself another headache. Just go to your local parts store and get the non GM part if you need to save some $$$.

[Crazy K]

ok, and I can't buy the 94+ rear calipers at any store, I would need to find those at a junkyard too???

 

 

I'm thinking of just servicing my current ones, as joeyb, and this site suggests: http://www.tpsgarage.com/TGP/brakes/servicing_rear.htm

 

You can service them but it the pistons, and not the slide, is stuck, that wouldn't fix them.

 

I went the J/Y route and found nearly brand new parts. I made sure the parts i got were in good condition... no torn boots, slides not binding... plenty of pad life... As Long as it is in good shape, there should not be a problem. (Used doesn't mean bad)

I paid about $25 for a set.... and got: rotors(still had the crosshatched marks from being made, like the ones you buy at the store) calipers that were in good functional condition, pads that were new, the bracket, the bolts, and the brake cable cut in front of the connection joint, with the bracket( removed from a donor car, with a hammer and chisel).

 

You can most of the stuff new, if you don't mind the premium cost. However, some places may want a core charge for calipers(maybe they wouldn't care if you gave them the old style ones?).

 

And use synthetic caliper grease for the slides(availible in Advanced, for instance, in a large fist sized container, forcheap). Some suggest antisieze, but I wouldn't use antisieze.

[Guest donkeykongrape]

I think I'll go that route. I'll go to the local auto parts store later today. Now let me get this straight,

 

I'd like to use the same pads I have on the rears now, on the new 94+ calipers. Why do I need a new rotor? And who said something about replacing the struts???

[SigEpCutlass]

I think I'll go that route. I'll go to the local auto parts store later today. Now let me get this straight,

 

I'd like to use the same pads I have on the rears now, on the new 94+ calipers. Why do I need a new rotor? And who said something about replacing the struts???

 

94+ rear rotors are larger. That's why many people do the upgrade to get a bit better braking performance.

[Justin]

I lubed up the slides in the rear calipers on my '89 and they've worked flawlessly for over a year since. The drivers side was so frozen that the outer pad actually fell out of the vehicle and I didn't notice because the inner pad was still working. Had to remove the caliper from the vehicle and press the slides out, then put new slides in that caliper. The piston and adjuster still works perfect, and now with new slides it stops as good as any W. I think the slides were about $15-20 for one side and another $20ish for pads, lots cheaper than new calipers.

[Crazy K]

The advantage of larger disc rotors is that the contact patch where the pads rub is further from the center, resulting in a larger contact area. Because the larger rotor is gripped further out, there is less torque to be overcome in order to stop, so the same focce applied to either rotor would result in a slower stop with the smaller rotor or faster stop with a bigger rotor.

 

But Rotor size is not that significant. The rotor change was only

front: 3/4 inch in diameter. from a 10.5 to 11.25 inch diameter rotor, a whopping 7% increase in size

Rear: 1/2 inch in diameter from a 10.5 to 11.00 inch diameter, a whopping 5% increase.

 

That mean the advantage is maybe a 6% decrease in brake force to do the same stop... But a maximum effort stop might be 6% less in distance....

 

If you were to use high performance semi-metallic pads I think these would be superior to upgrading brakes just for larger rotors.(assuming calipers were the same, that is)

 

94+ rear rotors are larger. That's why many people do the upgrade to get a bit better braking performance.

 

Yes, but it's not because it is a larger rotor... With the 94+ rear set up, the advantage is in the updated caliper design, a superior design, not the rotor.

 

AGAIN. I advocate upgrading the rear, but not the front. And you can still lock up the brakes if you want to (on the front) with high quality performance pads.

 

Answering your questions.

I'd like to use the same pads I have on the rears now, on the new 94+ calipers.

Sorry the 93- and 94+ use different brake pads.

 

Why do I need a new rotor?

On rear: The better brake caliper setup uses the 1/2inch larger rotor. period. No other way around it, it's a complete package.

On front: see below.

 

And who said something about replacing the struts???

That is for upgrading the front brakes. the bracket welded onto the strut extends 3/8 of an inch further outward(half of 3/4 inch diameter increase). The removable bracket and the caliper and pads are the same. the only other differenc is the rotor.

[Crazy K]

I lubed up the slides in the rear calipers on my '89 and they've worked flawlessly for over a year since. The drivers side was so frozen that the outer pad actually fell out of the vehicle and I didn't notice because the inner pad was still working. Had to remove the caliper from the vehicle and press the slides out, then put new slides in that caliper. The piston and adjuster still works perfect, and now with new slides it stops as good as any W. I think the slides were about $15-20 for one side and another $20ish for pads, lots cheaper than new calipers.

 

My set of warrantied calipers from autozone had slides in excellent condition when I returned them. But the pistons had siezed. They produced alot of drag, even when new, and much worse when old. I boiled the brake fluid on one trip while doing some hard drivng just becuase they were binding. The final clincher was when a realtive used my parking brake, and they wouldn't release. It was the caliper, not the cable. and the calipers were only two years old.

[Guest donkeykongrape]

wow lots of great information, thanks a lot everyone

[Crazy K]

good luck, let us know what you decide to do. (so we can argue more! j/k)

[Guest donkeykongrape]

well i went along and bought a replacement set of rear calipers, the ones that were meant for my car. I found out that one of the sliders on one caliper was seized, and the bushing on the other caliper was cracked and leaking. both seals on the tip of the piston were busted open, although the piston still seemed to work.

 

After replacing both calipers, when I was bleeding them, I accidentally sucked down all the fluid in the reservoir and started sucking air into the system, so as of tonight, my brakes suck even worse than before I started the project. The pedal basically drops to the floor when i hit it

 

After breaking my dad's hydraulic jack, and stripping a lug nut, and a whole day of work, I haven't gained a thing

 

Tomorrow I'm going to bleed the entire system and inspect the sliders on the front calipers. Can anyone inform me as to how to properly bleed the master cylinder?

 

Thanks in advance, everyone!

[Prospeeder]

fill up the resevoir, go to the passenger side rear brake, and open the bleeder and have some1 press the pedal and have a tube on the bleeder to a Jar of brake fluid, and wait untill no air bubbles come out (by doing this, it wont be able to suck in more air, just brake fluid if it does), then close it, and continue to the next rear, then the front passenger side, then the drivers front, then i think theres one on the master cylinder itself

[Guest donkeykongrape]

a bleeder screw on the master cylinder? Never heard of that before. I'll have a look at it tomorrow. IIRC, my service manual mentions something about disconnecting the brake lines off the cylinder and pumping until fluid comes out of the holes? Maybe I'm reading it wrong, someone correct me please!

[Prospeeder]

Umm im pretty sure you dont do that, you want the air out of the lines! Hows that gona help, im definatly sure you dont do that

[Pabz]

a bleeder screw on the master cylinder?

How did you come up with that idea?

[Crazy K]

You bleed the MC from the wheels, start with the longest line and work towards the shortest. (if you have an ABS equipped Master Cylinder, whihc you shouldn't, I start and finish with the bleeders located there, btw)

 

ie Right Rear, LR, RF then LF

[Guest donkeykongrape]

a bleeder screw on the master cylinder?

How did you come up with that idea?

 

Maybe I'm going crazy but it looks like he said there was a screw on the cylinder I'll bleed the system tomorrow and inspect the front calipers for seized sliders and let you all know of the status

[Crazy K]

if it has ABS IV like the 92+ lumina got and my 94 and 95 CS... it may have bleeder screw on the abs portion... which could be considered part of the MC....

[Guest donkeykongrape]

Ahh, well there you go I'm not going crazy! And no my car is not equipped with ABS.