Brake fluid disappearing into the ether... - Troubleshooting - VWDiesel.net The IDI, TDI, and mTDI source.

• Brake fluid disappearing into the ether... by watsongs on 12 Nov, 2005 16:57
• I had my head rebuilt and after I put it back on, I had no brakes.  I thought, well, the master cylinder looks pretty rusty, it probably bit the dust, especially given that the brake fluid was the color of Coke.  So I got one off a boneyard, with the booster and a vacuum pump.  Everythings back in, but the pedal still goes to the floor.  I've bled everything, got good fluid to all the wheels, but no brake fluid.  I've gone through, and yes, I'm serious here, two small bottles and one liter bottle of brake fluid, and still no brakes, and there are no leaks to be found.  I haven't pulled the wheels off anywhere to check (weather's been like crap, blowing 20+), but nothing's running down the tires or anywhere that I can see.  Is there some hidden resevoir that's not in the bentley or poor richard's?  Are the drums watertight and the fluid is filling up inside of those?  I am stumped.
• #1 by vwmike on 13 Nov, 2005 01:46
• There's a little rod that goes into the booster behind the master cylinder. If that disappeared it wouldn't make contact with the back of the master cylinder. Also, are you SURE it's the correct master cylinder for the booster? There are a bunch of different ones and if you try to put the wrong master on the wrong booster you could end up with such a situation.
• #2 by watsongs on 13 Nov, 2005 06:57
• I pulled the entire booster/cylinder assembly - mine's a '79 w/out the booster - and it's pumping; I can hear the thing going and was able to bleed the brakes by pumping the pedal.
• #3 by albsure on 13 Nov, 2005 15:10
• hi there, just my .02 here, did you bench bleed the the junk yard mc before installation. also sometimes you need to replace the cups and adjust the plunger rod depending upon if its a oem or an aftermarket part from  an independant manufacturer or rebuilder.
• #4 by watsongs on 14 Nov, 2005 17:19
• Well ,now that it's daylight, I pulled the booster and emptied out about a cup of fluid, and noticed that the carpet is wet...  guess that solves that problem!  Fortunately, the local shop ordered me a rebuilt MC for $45, so with the pic&Pull that makes a grand total of $70 ...
• #5 by watsongs on 16 Nov, 2005 10:27
• Ok, this is getting to be very wierd.  I put in the new MC, and have already gone through a liter (or is it two - the big bottle of brake fluid) and no end in sight.  I have the car up on blocks with the wheels off, and there is nothing leaking out anywhere.  Worse, since nothing seems to have changed in the course of 3 MC's; I'm starting to rule out that the problem was  with the original one to begin with, although it's nice to have a clean, shiny one instead of the rusty looking thing that was there before.  
  
  I'm completely stumped here.
• #6 by vwmike on 16 Nov, 2005 13:18
• Is this new master cylinder a Varga brand brazillian one? We tried to use one of those once and after number 2 or 3 that filled up the booster we gave up and bought a German master cylinder.
• #7 by chrissev on 16 Nov, 2005 14:49
• Quote from: "watsongs"

  Ok, this is getting to be very wierd.  I put in the new MC, and have already gone through a liter (or is it two - the big bottle of brake fluid) and no end in sight.  I have the car up on blocks with the wheels off, and there is nothing leaking out anywhere.  Worse, since nothing seems to have changed in the course of 3 MC's; I'm starting to rule out that the problem was  with the original one to begin with, although it's nice to have a clean, shiny one instead of the rusty looking thing that was there before.  
  
  I'm completely stumped here.

  
  
  what happens when you bleed the brakes?  do you get a lot of bubbles or does clean fluid come out the bleed nozzles?  I guess you have someone in the car and you are outside bleeding them (impossible to bleed brakes with one person unless you have a vacuum pump).  If you bleed all four brakes and you are getting clean fluid out of them, and you then close the nozzle on the last brake that you bled and get pedal pressure, but the pressure then decreases and you lose all your brake fluid somewhere, then I would say you have a leak.  On those early rabbits I think the brake lines travel through the inside of the car, under the carpets on the passenger and driver's side.  What happened to me once with a 77 rabbit is that the driver's side brake line rusted out (it was actually just this spindly little rusted hulk that cracked in half when I touched it) due to salt being brought in on my feet in the winter and then soaking through the carpet.  So you might want to pull your carpets out and check on those brake lines.  They may turn out to be pretty rusty.  That would explain why your carpet was soaked in brake fluid.  You can actually fit a lot of fluid in the front floor pan without it leaking out.  I once lost half my coolant into the front pan when the heater core went on an 84 rabbit.  The foam insulator under the carpet is like a giant sponge.  Anyway, hope that helps and good luck with your 79.  Nice to see people are saving the old rabbits
  
  Chris
• #8 by watsongs on 16 Nov, 2005 16:49
• Yep, that's exactly what happened.  I fiigured it out when the car was parked on a slight incline, and eventually a small puddle formed behind the driver's seat.  I figure there's about 3/4 gallon brake fluid in there...
  
  So, anyone got any good sources for interior carpets for rabbits???
• #9 by watsongs on 16 Nov, 2005 20:38
• So, after doing a little search on Google, turns out that there's a recall on the brake lines because, get this, they may corrode and leak.  I've read about VW standing behind their recalls, so I guess we'll put them to the test...
• #10 by watsongs on 18 Nov, 2005 13:04
• Boy, that padding sure can soak up alot of brake fluid.  It's a good thing that brake fluid is water soluble - I'd hate to have to clean this out with some kind of solvent.
  
  Ran new brake lines under the car (I didn't bother going to VW).  The parts store had a role of 3/16, and the compression fittings worked on both the old and new lines - I was worried about SAE vs metric.   Bled out the lines, and hey, I have brakes!
  
  Now, I wonder what the next problem will be...
• #11 by chrissev on 19 Nov, 2005 18:06
• one more interesting thing you might want to know about brake fluid (seeing as you have so much of it floating around in your floor pan)....it is paint remover.  Takes off automotive finish faster than a hurricane takes down a beach bungalow.  Beware when you have it on your fingers.  And maybe repaint your inner floor (so that the bare metal doesn't rust through)
  
  Chris
• #12 by watsongs on 19 Nov, 2005 19:14
• Actually, the fluid out of the floor wasn't too bad - shop vac, then two cans of brake cleaner, and pouring some acetone into the spots I didn't think the brake cleaner reached. It happened to be a sunny day, so I hosed out the carpets and hung them to dry on the fence.
  
  I had a can of cheap truck bed liner paint, so after everything was dry (used my twin 500-watt worklights to dry out the cracks and corners), I sprayed the pan down. I got some carpet padding, cut it to fit, shoved the carpet back in, and looks great.
  
  Now, the local yard just got in a 5-year old Quattro with black leather heated seats. Hmm...