kgorman

It appears most of my brake fluid has found it's way out of the system and down the center tunnel where the driveshaft in the C4 goes to the front diff. The fluid is leaking back to the rear and then dripping off the forward plastic underbody. I could not find any obvious leak, and I am considering just taking it to the shop. My fluid reservoir is about 1/2 full now! Yipes. Anyone seen this one before?

colo964

Not quite; I've had front and tranny area hydraulic leaks.

Front: Could be your booster pump switch (or abs/accumulator/pipes) leaking into the spare tire area. There are no hydraulics in the front diff. Are you parked on a hill making it go backwards? Did you drive like that, maybe the wind blew it back?

Rear: if you have all panels on and parked downhill, you could have a leak at one or both lock slave cylinders that looks like it drips at the front. They have weep holes which leak when their seals wear out.

kgorman

Thx, colo964,

I don't see any fluid in the spare area. I was parked front downward, and noticed the leaking from near the rear, but all along the panels. Then today, I noticed as I had the passenger side jacked up, fluid started flowing out of the bottom panel near the 'shark fin'. Clearly there is a lot of fluid on the top of the frontmost rear undertray. I have it removed now, but still can't find the source.

I will take a peek at the slave cylinders and see. A seal sounds reasonable because it crept up on me, but once it started leaking, then it continued to get worse and worse over the course of the day.

Youcef

Check the diff lock actuators for leaks, there is good chance these are leaking and the fluid is running down into the tunnel cover. No big deal if it is the actuator, quite simple to replace both.

Good luck.

kgorman

I can't find the leak.. I just dropped it off at Kahlers. I gave up, too much going on for me to spend too much more time under her. Hopefully it won't be too expensive to fix, but I know thats just dreaming. It's never cheap. ;-/. Thx for the help guys.

kgorman

CRAP!

bad slave cylinder, leaking pressure accumulator, need to replace horizontal lock cylinder. I spoke to the tech, and apparently what is/or generally happens is using the brake in rapid succession (or I am assuming) the traction control in rapid succession left the system with a debt in terms of trying to recharge pressure. Especially once the system starts leaking. I did notice that the 'green light mod' PDAS traction control light was lighting up way more with the new suspension, I wonder if now I am just either driving harder, or sliding a bit more where it gets activated more frequently. I suspect this is part of speeding up the failure as well. The tech mentioned these parts have a < 5 year life-span, so it's time for me to get mine done for some time now. He did mention that fixing this will help my braking feel, I wonder if it will effect my ABS issue.

It's going to be $$$$ to fix. Today would have been a good day to have a C2. ;-).

frankvan

KGorman: Horizontal lock cylinder has a life span of <5 yrs? Thankfully I don't know what it looks like or where it is - so it can't fail! (I'm sure it hasn't ever been replaced on my car - 89 C4 like yours).

Wachuko

Those lock cylinders are expensive!! I checked the other day thinking I would replace them proactively and quickly realized that I needed to wait until they failed...

I wonder if a hydraulic shop could rebuild them easily

If changing the slave remember to also replace the line while you are at it...

colo964

Let's see: 16 yrs - 11 yrs (for Sleep, Shower, SH%$, Sex) = 5 yrs. left over to drive. Yeah, that's about right.