syndicate_77

Hi
I have a question about bleeding my brakes after the brake fluid reservoir and rear left brake caliper was changed...

I have managed to bleer rear right caliper but when i´m trying to bleed the one on the left no fluid comes out... The caliper that was changed was clogged up by rust in the brake lines so i have fixed this and tested that it´s open by using a compressor blowing air throug the line from the abs module by unscrewing the pipe there an refilled it with brake fluid so it flowed without air from the caliper.

THe problem is that when i try to bleed the system again using both a vacumpump, pressure in the reservoir and usin the old fashion way i can´t get more than a little brakefluid out of the caliper.

All other calipers are ok, i have tried to use the vacumpump on all and i have no problem getting fluid out of the others..

I really need help getting a fix for this, been working on that problem for many days now.....

SloopJohnB@mac.com

Try pressure bleeding. That failing, you've got something blocking fluid from the reservoir, either in the abs unit or the line to the caliper.
You may also have to use vag-com to activate the abs pump to bleed it. But normally you should be able to get the system bled with a pressure bleeder at about 30psi (don't go higher--you'll probably bust the big plastic nut on the bleeder/pump assembly).

I like the pressure bleeder from bavauto.com. It has a quick disconnect that enables you to screw the cap onto the reservoir without twisting the feeder hose.

syndicate_77

I have tryed using a compressor to pressurize the resorvoir but maybe it´s not giving a constant pressure thats hig enough ? I´m a little afraid of putting to much pressure becouse the old resorvoir i had exploded when we tryed the first time

The line to the caliper is open, i have tryed using a oilcan pumping fluid through it and thats no problem, it flows free through it...

I have no chance getting my hands on a pressure bleeder at the time and i live in the countryside beeing dependent on having a car going anywhere...

I guess the abs unit might be blocked somehoe but is it possible for me to do something about it without bying a new one?

Going to try bleeding it using VAG-COM tomorrow but if that fails, any suggestions??

sounddude

Just a little more info, Have you tried disconnecting the line at the caliper and pushing fluid out of the line with the pedal? IE... Are you sure the problem is between the master cyl and the abs module or is there a chance the the replacement caliper is damaged?

syndicate_77

I have tryed doing this to and then the fluid flowed out of the line at once... But it just won´t refill the pipe with new fluid...I have actually svitched back to the old caliper becouse we found out it was a propblem with the caliper beeing blocked by rust, something we managed to fix when we first identified the problem...

So it´t most likely back to beeing a problem with the abs system but soon on my way to try bleeding it again and hoping that will solve the problem.

sounddude

Have you tried the other 3 wheels? A bad master cyl will usually effect two wheels. (most german cars do opposite corners) You could have a master cyl issue.

Prospeeder

I have seen where the pushrod in the booster becomes detached from the booster itself and the master doesnt get full travel, and it will not bleed one or 2 wheels. I have banged my head for days before yanking the master off and finding the pushrod is no longer attached to the booster and a little star washing is floating around. In that case new booster time. All the times i have had this happen it was for unrelated things like a brake hose or caliper. I assume its the sudden loss of brake pressure and pedal rushes to the floor and does something to the old booster

Also my bleeding method is, pump pump pump pump hold, then open the bleeder. Repeat untill air is out.

syndicate_77

Update : Problem solved... It was a mastercylinder issue, changed it today and suddenly i had brakes and drove my car home

syndicate_77

Update : Problem solved... It was a mastercylinder issue, changed it today and suddenly i had brakes and drove my car home

syndicate_77

Update : Problem solved... It was a mastercylinder issue, changed it today and suddenly i had brakes and drove my car home