lots of brake fade

[T77911S]

time to dig into the brakes. 86 930

this is the second time i have done a few runs up to around 120. after about 4 times the brakes are GONE.
i am thinking i have some stuck pistons. it only has around 44k on it so i am sure the brakes have not been used enough to keep them working.
just have to figure out a way to jack up the front of this one. it has a condensor where i use to jack the 77.

[mnez]

I jack mine on the steel bar that runs in front of the condensor. For years now. Works perfectly.

[T77911S]

i saw that bar but i did not think it was strong enough.

[bkreigsr]

it's not
use the factory jack holes, one side at a time.
or, jack one side then support the a arms with a 2x4 and raise.

sounds like you're rotors are glazed, or not compatable with whatever pads you're using.
stuck pistons would not give you 4 good stops, then stop working
Bill K

[schumicat]

what brake pads are you using?

[T77911S]

i dont kn ow.

only had the car for a few months and have been chasing the engine miss since i got it.
i am ready to get on to some of these other little things like this that need attention.
i was going to do the brakes while waiting on the wastegate.

[awhnry]

pads are probably glazed. Remove and scuff them up with sand paper or replace with compatible pad to your use. New pads however may require new rotors depending on material used. You might also want to bleed the brakes or purge the system of brake fluid too(while you are at it)

[mnez]

I've been routinely jacking the front of my '86 on that bar for years, many times, to swap wheels, pads, or to work on the front end (using axle stands to support the car of course). It is plenty strong enough. It's never moved a bit.
I'm no engineer, but I know it works.

[HawgRyder]

I don't remember the number of times I have been asked to build a "hot" engine for a friend or customer.
When that happens...I ask what kind of new braking system he would like.
The enevitable answer is "what?"
I explain that If you can go fast...wouldn't you like to stop?
Brakes are a balancing act...you need to spend money to stop...but how much?
Depending on the application...better disks (vented?)...better pads (sometimes much harder = more pedal pressure) and much better cooling for the disks AND calipers.
A higher boiling point for the brake fluid...maybe even having to go to silicone fluid which requires new master (because of the seals) and lines flushed...and new seals for the calipers.
An interesting problem for all.
Bob

[tonythetarga]

The stock 930 calipers and rotors are awesome. BUT, as hawgrider says, you need the correct fluid, suggest Motul 600, and the right pads. If you do a lot of high speed braking, such as on the track, you need capable pads. A street/track pad is something like Hawk HP Plus, something more aggressive can be Hawk Blue, Pagid Black or Porterfield track pads (can't remember #). You need to do some homework on stopping that car.

[T77911S]

finally got around to getting it jack stands. took about an hour. what a pain.

anyway, pads are like new, bad news is they are minted. i don't think they could have found a cheaper pad.
but, will the pads cause brake fade? thought that was the fluid getting too hot.

no matter. going to get some better pads. looking now.

[T77911S]

pagid black?

[T77911S]

holy smokes!!! $277 for the fronts!!!

the hawk hp is 140 for the front.

[T77911S]

what about cool carbon pads?
think they have some ceramic in them. someone told me not to get ceramic

[tonythetarga]

I have a set of cool carbon pads, new in box, for $70 shipped to you. They fit the 930 front or rear as well as 964 front or rear.
There is nothing wrong with cool carbon pads . They are not dusty to the wheels and do not squeak as much as other street/track pads.
If your intent is street and maybe some track they are OK. If you are going full blown track and need the best pad, you're going to have to get used to paying more for pads.

[RSTarga]

Never EVER use silicone fluid. It is horrible stuff.

[Bob Kontak]

Originally Posted by tonythetarga

BUT, as hawgrider says, you need the correct fluid, suggest Motul 600,

Gotta go with this as a starting point.

[Jesse16]

Don't think you mentioned that you've flushed the fluid either. You need to run a full liter or more of new fluid through the system to remove any moisture. I think if it hasn't been done, I'd simply start with usual high quality ATE fluid. Its relatively reasonable price wise. If after all else is done and you still aren't satisfied, then try all the motul and other options that are 2x to 4x more. I've never had an issue with a properly flushed system and ATE.

[aston@ultrasw.c]

Originally Posted by T77911S

finally got around to getting it jack stands. took about an hour. what a pain.

anyway, pads are like new, bad news is they are minted. i don't think they could have found a cheaper pad.
but, will the pads cause brake fade? thought that was the fluid getting too hot.

no matter. going to get some better pads. looking now.

fade is when the pads overheat: the pedal remains firm but brake torque is dramatically reduced

boiling/vaporizing is when the hydraulic system overheats: the pedal goes to the floor and there is no braking at all.

[michael lang]

I don't know if the problem has been resolved since it's been a month since the original post. It sounds to me like the car just isn't/wasn't driven. I don't know that I would go with such an aggressive pad or fluid as some had suggested. Based on the original post, I would start with a very thorough brake flush. Maybe two cans, one ATE Gold followed up by a can of ATE Super Blue just to make I got it all. Then a good roadtest with a proper bedding in procedure. If it continued, then I would check the bottle to see if the fluid level dropped at all and go from there.
Please update the thread and let us know what you found