Wednesday, July 21, 2010

Master Cylinder @#%($&%*!!!

Well, I have hit a roadblock.  The wheel cylinders have been replaced, bearings repacked (Thanks Dave Curry!) and everything looks great ... except when you step on the pedal the brakes lock.



The wheel cylinders and pads definitely needed replacing.  One side was weeping ever so slightly out the seal, and there was a lot of rust.  Everything came out looking and feeling pretty good, but after bleeding them I was having a really hard time getting them adjusted.  I would have them where I thought they needed to be, Dave would depress the pedal, and the wheels would be locked up again.  This is after enough pedal presses that the pads should have had time to adjust/center themselves.

The feel of the pedal is also not so great.  There's a lot of pedal travel before it encounters the resistance of the master cylinder, and when you do, you have to push harder than I would expect for it to stop the wheels.  Then, at that point, the wheels are locked, and the only way to unlock them is to open the bleeder valve and let a little fluid out.  Thereafter the wheels pins nicely (until you hit the pedal again).



So, I think it's going to be time for a master cylinder.  Part price seems to vary.  I'm looking at German made parts.


Thing Shop: $120
JBugs: $59
Chirco: $89


I'm thinking about ordering from Chirco because the guys there have been so insanely helpful to me on the forums.  I need to compare shipping, and I don't want to wait another entire week, so I'm probably going to do 2 or 3 day.


Changing the master cylinder doesn't look too bad, but I currently have a far more pressing item to fix: the air conditioner on my Jeep Liberty Renegade has siezed and is smoking, making the vehicle undrivable except for very short trips (and with the windows all rolled down).  So that's the project for Thursday - don't expect any Thing updates for a few days (sorry).


Update: the master cylinder apparently needs to be bench bled.  Here's the procedure:


http://www.vw-resource.com/bench_bleed.html


Looks like it will require a lot of patience to pull this off.

1 comment:

  1. I had a similar problem with the Cadillac a while back, one of the front calipers was binding.
    Turned out to be a bad hose. I assumed it was probably broken down internally in such a way that it would allow fluid to be pushed through but then would hold pressure. If opening the system relieves the pressure can you open the system at other places on the way back to the Master cylinder? Hmm are we still allowed to refer to them as master and slave?

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