Source for proportioning valve seals - page 2 - Troubleshooting - VWDiesel.net The IDI, TDI, and mTDI source.

• #15 by Chuck1978 on 29 Feb, 2020 11:24
• Here we go. Mine + eBay spares, to build one decent unit, lower plunger assemblies are still together, meaning they are seized!
  VW Mk1 Rabbit Pickup brake proportioning valves179612151a by chuck_lambert78, on Flickr
  
• #16 by ORCoaster on 29 Feb, 2020 23:13
• Yeah, don't you just hate how those red pistons get stuck in the end of the nut assembly.  Once you get them the tiniest bit loose they go shooting in some unknown place in the shop. 
  
  I was able to obtain a second proportional valve from another VW parts collector, Thanks Dave, but I wonder if my pistons are still hanging up.  I just don't get the stopping power from the rear brakes.  That leads me to think that they are not staying charged and when I step on the brake pedal most of the first stroke ends up setting up the brakes for a proper stop.  But who double pumps brakes? 
  
  Going to fiddle with them again when the weather warms up.
  
• #17 by fatmobile on 09 Jun, 2023 22:32
•  Someone on the vortex found a source for the MK1 brake proportioning valve seals:
  https://www.vwvortex.com/threads/brake-proportioning-valve-mk1-rabbit-golf-rebuild.9535470/#post-115967790
  
   They are the same as on some 92-95 dodge cars:
  https://www.musclecarresearch.com/mopar-4485829-brake-valve-seal-kit
  
• #18 by ORCoaster on 10 Jun, 2023 22:39
• What a deal, 15 bucks for parts that I have searched for all over the place.  I even have gone to hardware and auto parts stores hoping to at least get a couple of them.  I have several valves and now they can all be rebuilt.
  
  I was buying them from people who are scrapping their cars because they are generally easy to cut off and send in a small USPS box.  No one wants them unless you do when your brakes don't seem to be able to bleed easily or the rears don't seem to be working and the front discs are smoking hot to the point you can smell them. 
  
  Thanks a bunch for this. I already ordered two sets. 
• #19 by fatmobile on 12 Jun, 2023 22:47
• As soon as I saw that post, I thought of you and your search for a good one.
   And my small stash of them with the seals getting older.
  I bought a couple sets too.
  
  In the picture, the dodge proportioning valve looked just like the VW one.
• #20 by ORCoaster on 13 Jun, 2023 21:52
• This had me wondering if we could just have bought that valve if we would have known it was being used in those vehicles.
  
  The price is way too high.  I like the 15-dollar diy fix. 
• #21 by srgtlord on 15 Jun, 2023 11:00
• FYI the MK1 and MK2 proportioning valves are a different diameter. I bought a set of seals that were brake fluid rated based on a discussion on vwvortex but the orings were bigger. If I ever have to go through the headache of finding replacement valves again Im just jerry rigging an mk3 prop valve with a fixed height as they can still be found new. Just have to bend a coat hanger to keep the variable adjustment in place. I had that on my 1990 mk2 golf as it came stock in those years and the variable spring broke off. The coat hanger trick was on there for well over 50k miles.  It was mounted on the rear axle beam but with a fixed height you can put it anywhere
  https://www.autohausaz.com/pn/13597674-1H0612151?utm_source=google&utm_medium=cpc&utm_campaign=feed_VW&gad=1&gclid=Cj0KCQjw7aqkBhDPARIsAKGa0oLCg4algoi0L5Wq5Dy-861wgjPdKM3bEkGafugvdthQu56AucSHGEUaAiIPEALw_wcB
• #22 by ORCoaster on 24 Dec, 2023 19:09
• Digging up an old thread only because the VW part number matched my search.  And this is good stuff.
  
  Today I spent a bit of time at the workbench tearing into the valve that was on my pick up.  I have been noticing that the brake pedal is low and the stopping power is less than it needs to be if I am carrying any amount of weight.  Say 300 lbs plus myself.
  
  So, after disassembly I got into the inspection part and found that the one side of the valve body where the lines would connect from the rear brakes was pitted.  So that is likely why I am missing the ablility to really get a good pedal and maybe why the pedal I do get will bleed down after a while if I push and hold on it. 
  
  I put on another valve body and plugged the lines to the back and I don't have that bleed down effect now so I am pretty sure I don't need a new MC, booster or cylinders.  Most of them have been replaced in the recent past anyway.  That doesn't always mean they are still good.  Just look at those posts about multiple MC fails and the trouble they had getting them to bleed at all.
  
  I hope to swap out the valve on the truck now with another that I verified is good and has new seals in it.  It sure is a pain to replace that sucker.  Terrible location and why?  Maybe I will relocate it as I have to do work on it and that entails new lines to the back.  I may keep you posted, but maybe not.
  
  Merry Christmas everyone. 
• #23 by fatmobile on 25 Dec, 2023 00:30
•  I got a couple of those kits.
   A couple of mine should get rebuilt before they start to corrode.
  Pretty easy once they are off the car.
• #24 by ORCoaster on 25 Dec, 2023 17:50
• I was looking for information from you on the proper orientation of those ribbed seals that go on the pistons.  I tried the way I thought, ribs to the inside of the valve, and got no joy from that.  So I had a second valve and put the seals against the valve body, and ribs against the piston.  Now that blocked off the fluid to the rear lines and that for sure is not right. 
  
  I think after I took the first valve off and saw the pitted nature of the bottom on the valve body I figured out why I didn't get success the first time around.  Fluid was freely passing around the seal so of course it didn't do any of what it was supposed to do.  Another valve and a proper fittment on the seal should yield success.  At least that is the logic.  VW's can defy that.
• #25 by fatmobile on 26 Dec, 2023 00:38
•  Are you paying attention to how the old seals were sitting before taking them apart?
   It's been so long since I took one apart and have been too distracted these last couple days to dig into the brake stuff bucket.
• #26 by ORCoaster on 28 Dec, 2023 21:47
• Well, my problem was that it was a year ago that I tore the valve apart and the seals were one mushy mess down in there.  So no way to know what was what and how it was orientated. 
  
  When I got a second valve, hoping to get better sealing it too was nasty.  So those got cleaned off, bagged up, and thrown in the cupboard.  Then along comes the reseal kit information and I am like, great I can finally pull the one off the car and swap in a rebuilt one.  I should have pulled the one on the truck, noted how it was put together, and then rebuilt but I didn't have the time to do that.  I had time to rebuild one weekend and wait for better weather. 
  
  That happened a couple of weeks ago and I just swapped them over hoping for the best.  I did look at various forums and the Muscle Car site where I bought the kit.  They had some pictures to look at so I tried it that way.  But putting good seals in the bad valve body didn't help any and my success was nil if not worse once I put in half a day getting it in and bled and all. 
  
  Now knowing what I know I rebuilt another valve and will try it when the weather gets nice.  Till then I am driving the hybrid Pickup and enjoying the ride and in-town mileage. 
  
• #27 by fatmobile on 29 Dec, 2023 20:39
•  oh, quite a journey to finally get good brakes.
  
   This project is moving up my list, the brakes on (Pa)tina are a little mushy.
   I have been hoarding these valves.
   Seems like every time I worked on someone's rabbit brakes, I'd lose another one of mine.
   Their valve or seals would be bad.
   Sometimes I could clean them up and get one working but usually I'd have to dig into my parts hoard.
  
  But I still have some left so I can rebuild a couple, then swap one in.
  
  I like to take the car out to the gravel road, drive slow then hit the brakes and see how they slide.
   See if all the wheels are helping to stop,.. evenly.
• #28 by ORCoaster on 30 Dec, 2023 12:24
• You are where it gets cold enough for snow are you not?  That might be better to use than a gravel road.   A big flat parking lot perhaps. 
  
  
• #29 by fatmobile on 31 Dec, 2023 02:16
•  Oh yeah, in the winter I don't have to go far to find a slick spot to test the brakes on.
  Or most winters anyway, I can use the street.
  
   But gravel allows me to be going a little faster and see how the tires grab and when.
   Sometimes a slick road doesn't grab them enough, it doesn't pull on them and test the wheels stopping ability.
   And you don't have to be going very fast to have the prints from the rear tires run over the tracks of the front.
   making it hard to see where they locked up.
   
   I'm about three blocks from gravel road.
   I don't do it often but sometimes wonder what that old guy thinks about me
  driving slowly down his road and locking them up,
  getting out to check then doing it again with another walk around.
   Or what the next person thinks about the odd tracks in the road, ha.