NoSubEDU

I've always been told stay clear of 5.0...go with 5.1 if you want a DOT 5 fluid.

(This is coming from an Audi guy...the brake fluid was also used for the clutch mechanism. The silicone would cause clutch failure...)

JimProuty

Okay, here's the final tally on fixing my fading brakes:

$407 for a master cylinder I may not have needed (Motor Sports Intl).
$2229 for an ABS hydraulic control unit it clearly did need (Stuttgart Autotech).
$169 Misc Other parts
$720 Labor
-----
$3525

Ouch

On the positive side, my car didn't actually NEED the engine pulled to fix an oil leak that dropped an oil spot the size of a 50 cent piece over a period of 4 days, as the dealer (Sunset Imports in Beaverton) recommended. That "saved" me $4000-$6000.

So "hats off" to Stuttgart Autotech in Lake Oswego; having brakes I can trust is quite a relief. Now to try out those twisties on the way to the Oregon coast!

JasonAndreas

What did you do with your old ABS hydraulic control unit and master cylinder? If you still have them would you consider flushing them out with DOT-5 just to see if it will dissolve the spooge?

Texas993

I need to mention for folks reading this string in the future:

There are several posts about this issue on the PCA.org tech section. I had the same problem and did not need to go through the expenses above.

It appears to be fairly common with cars that have not had routine bleeding.

Someone simply replaced the fluid with an older type DOT fluid and drove the car for a week. Then he flushed the system and put in the correct fluid. The older type fluid acted as a cleaning agent and dissolved the waxy substance. This method is certainly worth a try as it is cheap.

My master cylinder was replaced and repetitive flushing solved my problem.

Joel Reiser at PCA tech helped me through the process and was curious enough to ask for my old master.

Simply for the archives.

JimProuty

Stuttgart has the old ABS unit, and they did first try flushing it out with brake fluid (I don't know if they used DOT-5), but that didn't fix it like they hoped it would.

And I don't have the old master cylinder; Motor Sports Inc does. Since they agreed to let me pay them only for the new part, I don't feel entitled to the old one. (And I don't have any brake flushing tools.) I do wonder, however, whether replacing the master cylinder was necessary.

Thaddeus

Power Bleeders are a terrific thing, I bleed my Porsche once yearly (payback for all the times it bleeds me )... I alternate using ATE Blue with ATE Gold so I can tell when all the old stuff is out and the new stuff is in. NOTE/WARNING: this is on a 928, I have no idea if my choice of brake fluid is appropriate for 993's. It takes me about an hour to do. Cheap insurance.

BobbyT

How does one cycle the ABS when flushing the brake system to ensure that it gets flushed, too?

Greg Fishman

Use a "Hammer" tool that plugs into the diagnostics in the car. Do a search and you will see many posts on that matter.

chris walrod

Or, do a track day. Rebleed, do another track day and rebleed. By then, enough fluid should have been exchanged. Maybe not?

ecobb993

I had the same symptoms (sinking pedal and white gunk) only a few thousand miles and a year or two after having my independent shop flush the system (among lot$ of other things).

Took it back to them and they said this is a problem found only in 993s and has, in their opinion, nothing to do with moisture absorbtion. They said, "no one knows what the cause is, but it's only with this model. Maybe it's an incompatibility of brake component materials".

They flushed and flushed and got my pedal back to maybe 90%. Next time I'll flush it myself, to be sure it was done thoroughly.