Jake G

I checked the DIY section and used the search function and could not find the answer. So I was having issues with the brake pedal slowly dropping about an inch before it bottoms out. It will hold there. Last time this happened I bleed the brakes and the problem went away. Just finished bleeding them and the problem is still there. I think I remember reading that there is a ABS issue that might be causing this issue? Anyone have the fix. It reminds me of a bad master cylinder except with a bad master cylinder it tends to bleed all the way to the floor and then you can pump it back up. It is not doing that.

Jake

Tonydec

How is the brake fluid level? Check the floor boards and in the bonnet for brake fluid. If there is nothing there, check all the calipers. If it's not a leak at one of the calipers, then you have a bad seal somewhere in the master or ABS. I would have bleed them also to make sure it's not a monster air bubble in there.

Check over on p-car.com too, might find something there.

Jake G

No leaks. Not sure how he ABS system works. I coul swear that there was a thread on this in the past few weeks. I just can not find it.

Jake

Jake G

After reading a few DIY posts on brake bleeding it could be that I did not get all the air out. I did not know I needed to clamp off a vent tube. Hopefully that will fix the problem. Just confirming the order should be Lr,Rr,Rf,Lf?

Jake

kjr914

C4/C4S ABS are somewhat different from C2... I can't tell what you have from the avatar. C4(s) you can also bleed the accumulator (black ball) for the ABS. There is some preferred inside/outside first order for the caliper bleed nipples (which I can't recall right now) and the "bang on the caliper with a rubber mallet to knock loose any air bubbles while bleeding" thing.

Sounds like another round of bleeding might be in order. I've always used the "friend's foot, slow and smooth, halfway to the floor and back up" method to bleed, while I work the bleeders.

edit:
vent tube for the fluid reservoir? Then you are using a pressure bleeder? You might try the friend's foot method... might flush out air in the master.

edit2:
Start farthest from the master cylinder and fluid reservoir (LHD) and work closer. Rr, Lr, Rf, Lf

nine9six

Yep, you still have air in the line somewhere.

Just out of cuiousity, are you using a Motive power bleeder?

If not, how are you bleeding the brakes? The above mentioned tool is priceless IMHO... Complete brake caliper removal and slave cylinder bleeds all by myself...Easy peasy.

BradB

I recently went through the same issues when flushing my fluid. A search will likely find my posts. In my case it took a bleeding of the accumulator to fix everything. It's easier than it sounds at first and there are a couple great DIY posts on it. Search for bleeding and for accumulator.

I use the Motive bleeder and it works excellent.

Jake G

I don't have a pressure bleeder. I was using the trusty 8 year old son on the brake pedal method. I still remember helping my Dad do the same thing when I was that age. I will check out the accumulator thread.

Jake

nine9six

Jake,
I think the Motive Power Bleeder is a wise investment, and you dont have to worry about stroking the master cylinder past its normal range of operation, and risk damaging the seal.

Besides, eventually your son will grow older and go off to college; and we all know how the wife feels about pumping the brakes