Break issues

[Toph]

Hi all,
I recently set out and completely replaced rear axle bearing, breaks hardware, break cylinders, refinished the backing plates. I got this all completed completed and back together for the July show. On may way back from that show I had a front wheel cylinder issue, it was leaking, the seals were shot. So I set out and replaced all the shoes, wheel cylinders, hardware, bearing and had the drums turned.

Once the front was re-assembled the break pedal was very sponge. So I bleed, and bleed, and bleed some more. Nothing changed. So I busted out my mighty vac. No change either. Then I went on vacation for two weeks.

When I returned I tried bleeding 4 more times. So I pulled the master cylinder and discovered it was taking on air. So I replaced that. I got a TRW from Pam at North Idaho Imports. I bench bleed the new master, installed it, and I have no pedal. Its not gaining any pressure.

Here is what I have done so far.
Checked all the lines and wheel cylinders for leaks, there are none.
Tried using a mighty vac, did not work.
Pulled and cleaned the fluid reservoir, no issues.
Bought a air bleeding system, it pulled the break fluid out of the lines that was in there, nothing past the master.

I followed the bleeding procedure listed in the Muir book.

So I am at a lose at to what else I can try? Is this a master cylinder issue? It bench bleed fine. Could the new one be faulty? Also in my research some have suggested the push rod my need to be adjusted. Some would say to adjust it, others say don't touch it?

So I am turning to all of you. I hope that maybe someone could provide me with some new direction. At this point I have exhausted all that I know and understand. Sadly if I can not fix this I will have to take it to the shop, something I have never done with my VW.

[dukebradbury]

Toph,

I have never experienced the issue that you have having. However, it does sound like your pushrod could be an issue. If it is adjusted incorrectly, in never really "closes" the cylinder and constantly allows brake fluid to leak back into the reservoir.

Have you adjusted the pushrod?

Obviously without seeing it, it is very difficult to help. Sorry

[RichardK]

try pinching off all 4 brake hoses with vise-grips, or the actual tool to pinch them off, I always use vise-grips, step on the pedal, it should be rock hard and at the top, if not, that's a master problem which it sounds like you do not have, try bleeding master if you do not have a rock hard pedal, once your past the master problem, release 1 vise-grip and step on the pedal again, how much farther did it go down? bleed that 1 wheel cylinder and step again, if you feel all the air is out of that 1 cylinder, maybe the shoe adjuster needs a couple of turns, you should have a rock hard pedal again and at the very top, repeat for each cylinder and shoe adjustment, when I do this it's usually the last wheel I work on that has the problem, haha, but by isolating each at the brake hose you find the culprit a lot easier, expanding brake hose, bad cylinder, or out of adjustment, hope this helps

[Toph]

Thanks for your help, it turned out to be a faulty break light switch. Once that was addressed and the system was bleed it worked perfectly.