the flyin' scotsman

Jim.............its your life and the lives of others who are at risk if your brakes fail; be very cautious with whatever you do with this situation.

Jadz928

I understand there are two options here.
1. Do a system evacuate and flush. Rinse and repeat. Inspect rear calipers and seals closely.
2. Completely rebuild the system.

I'm leaning toward #1. And here are my reasons.
- PS fluid has only been in the system for only 2 days.
- Brake and PS fluid are not that much different.
- A failure would not be catastrophic. For instance, if the brake master fails, it would not be immediate failue. One would notice a general degradation in brake pressure.
- The rear brake lockup is odd. The PS fluid may not have been the root cause. There could've been a blockage in the line.
- I don't think I boiled the fluid. At least not from seriously hard braking. I had only been on the road for 5 minutes. The fluid around the rear calipers and rotors had boiled but more than likely did not make it's way up the system to the brake master.

#2 is not exactly a cost issue. I am seriously weighing this from a safety pov. The problem is I'm not convinced I really need to do all of this. I need to get some feedback from Penosin about PS checmical characteristics with respect to rubber seals and hoses.

Thanks everyone for your responses and candor. This isn't easy for me to be public about, but I'm doing my best. I'm embarrased because I've never f'd up this badly with respect to any of my 928s.

Plus, this was a big let down because I was feeling very good about the job I did. I researched RL, and systematically executed the job. Little did I know, the stuff I had on the shelf from when I bought it a few months back (slated to go in Chewy), was the wrong sh*t.

Jadz928

Malcom,
I get it. I 'mconsidering this situation with much brevity. Thanks.

..now quit freakin' me out.

Dean_Fuller

Jim,
Don't worry about being embarrassed....we all do stuff sometimes. I agree with your approach. A real good flush and Daily inspections to see about leaks. The brake pads may of glazed though...new pads may be a good idea. Just be safe and take it easy for awhile. If it starts to leak then you know what has to be done.

ew928

If there is a blockage in the line, can you be certain a double flush will remove the obstruction from the system. Or just push it further along somewhere so it can manifest itself later on.
Just posing this for a thought. Think you know which camp I'm in.

the flyin' scotsman

ok great just lookin' out for ya.

Nicole

Sorry to hear this!

Back in good cold Germany, in the winter time, little critters (Martons) liked to jump into the warm engine compartments and bite a variety of rubber stuff. On my car, they loved the CV Boots, so when I started driving the grease splashed onto the brake lines. Within hours I had a strong pull to one side - which was my indicator that something was wrong. The first time the shop did not realize the brake lines were swollen and just replaced the boot. Then they cleaned the brakes. Then they said I had a bad caliper. After all this did not help, one of the technicians remembered a manufacturer recommendation to always replace the brake lines after CV Boots went bad... That solved the problem, and was subsequently repeated after each Marton attack.

Moral of the story: Brake lines can swell quickly.

M. Requin

Thanks for thisthread! I understand about being embarassed, but your learning experience can be invaluable to others. Nicole's post is an excellent example, and between the two of you I've learned something important. Good luck with repairs.

Randy V

That Pentosin stuff is also real expensive, isn't it?

I'm thinkin' that's the same stuff used in BMW automatic leveling suspension systems?

mark kibort

No problem. No cut on your friend intened. These things are mechanical and the nee jerk reaction is to replace everything. I dont doubt your Bro is a trustworthy, all around good guy, and he might have seen a total destruction of the Saab brake system due to PS sterring fluid in the brake system.
My point was that if its only been a day or two, not much can happen, at least with these kinds of componets.

My point was that i have a real good idea of what happened, as i dealt with a failing master cylinder that did almost exactly the same failure. the reason, the fluid could not equalize when the brake released. so, you have the classic brake drag and it vaporizes the fluid and pretty quickly fortunately, the brake falure happens and makes a lot of noise and vibration as it happens. I dont think he allowed it to happen for more than a mile or two , if that. so, the temps were much less than what i see on the race track, or especially what scot will see on the race track with his smaller brakes. we get those things so hot we nearly vaporize the pads themselves!! (800-1000 degree F) anyway,
the only real concern would be the corrostion factor or if a seal had actually failed due to the ps fluid. easy to check. Just flush the fluid well, and test. if the brakes clamp and release, take it for a drive and see if it clamps and releases. drive it for awhile and see if the rear rotors get hot to the touch. (spit on them first before touching) draging brakes will get rotors hot to vaporize water on the disc rotors. normal operation just makes them warm to to the touch .

One of the things that shops will always do, and they have to, is recommend full equipment change, due to liability. If we can do more research and do it ourselves, you can save the extreme precautionary costs. from the shops perspective, its not worth the extra effort and risk.

since it is the rear brakes that failed, there is a HUGE safey margin of error here that if they fail, the car will still stop just fine. however, i would be also worried about corrosion in the front brake calipers. after 4 days, i dont think much damage could be done.

The reason they locked up and did so, mainly in the rear, was because of the bias valve size and viscosity of the PS fluild. it was not able to return back to the reservoir and was not able to release the clamping force. the boiling point of PS is near the same if not better than most brake fluids, so that wasnt the reason. plus, boiling brake fluid only puts air in the lines which is thiner than oil and can return to the reservoir easily. this makes the pedal soft.

mk

Jadz928

I'm so pissed I lost my lug lock key. It appears to not be very easy to get a replacement (understandably). Esp if you don't know who made it.
So now I can't get my wheels off to flush the system. Got any ideas?

The lug is internal tooth (female), key is external (male). Lug appears to have a left-hand thread on the outer diameter.

ew928

Have any close picture of the locking lug?


Have heard some have success in jamming a cheap socket over the lock lug (if the lugnut has surface locking surfaces) and deforming the socket onto the lug to unscrew the lugnut.

Good luck.

Jadz928

I'll get a pic this eve.

I guess my real question is, being most imperative... can you crack the bleeder valves w/o taking off the wheels? I'm running stock 16's

Need to get that PS fluid out ASAP.

ew928

My 88 rear calipers had inboard and outboard bleeder screws. Probably too tight to try and crack the bleeder that's on the wheel side if the calipers are the same as mine.

I remember cause the inboard left bleeder of mine corroded in caliper and broke.

Tampa 928s

Does it ever stop?