Author Topic: brake pressure regulator (Read 6055 times)

Possum79 · « **on:** September 27, 2008, 12:36:05 pm »

So I noticed the other day that my brakes went to the floor and hardly worked. Looked to find I was low on fluid. This happened before so today I went to check for leaks because my pads arent worn out yet. Found that the pressure regulator in the rear is leaking from the side of it. Are these repairable or just replacement parts? I looked around and 130 plus shipping is WAY out of my range. Im broke and looking for options.

Also If I go to a junk yard are these all the same between rabbits/cabrios/diesel/gas?

jtanguay · « **Reply #1 on:** September 27, 2008, 01:15:57 pm »

i personally would just replace it, but in your situation you'll need to grab one from a recently wrecked (or junked) car. the longer it sits, the worse it will be. it seems like nobody ever bleeds their brake system, and this will just make the brake fluid turn all acidic and eat everything. the brake fluid is highly hydroscopic so it retains moisture and creates hydrochloric acid IIRC. this is due to the fact that the brake fluid is not a sealed system. the cap has a vent hole to allow air to move in and out during hard braking.. IMO thats a crappy system, and i would rather have some sort of bladder bag to allow movement.

make sure that it is not a wheel cylinder leaking first though. or if one of the lines is starting to leak.

maybe someone should ask prothe to start carrying those, as well as brake lines. :lol:

Possum79 · « **Reply #2 on:** September 27, 2008, 01:29:02 pm »

Its definitely not the wheel cylinders. I got under there and checked it out. Looks like I may be getting a junker as a temp untill I can afford a new one.

Dakotakid · « **Reply #3 on:** September 27, 2008, 02:46:05 pm »

I thought autohausarizona had them for $100 and they pay freight over $75. It has been a year since I priced it though.

I got by with a used one which had sat for several years on one of my wrecks. But, it has never truly had that "newish" feel about it.

Possum79 · « **Reply #4 on:** September 27, 2008, 06:57:29 pm »

I went to autohaus and there is no listing for one unless im blind. Germanautoparts has one and so does rabbitparts but they are both around 130. I was just thinking though If I replace it how am I going to adjust it. I dont have the gauges etc to tune it.

jtanguay · « **Reply #5 on:** September 27, 2008, 08:13:58 pm »

you don't need to adjust it. just when bleeding the brakes you need to follow the instructions and pull back on the lever to open the lines. i wonder if it would be possible to use a proportioning system out of another vehicle application... would need to get the right fittings...

http://parts.autopartsonlinecanada.com/parts/apocanada/wizard.jsp?year=1991&make=BM&model=M3--001&category=N&part=Brake+Proportioning+Valv

now even that is fairly expensive, but something like that seems like it could work, no? i know this would require two, but still... just trying to think outside the box, but i know how everyone loves keeping their cars 'stock' :roll: :lol:

i swear i saw the proportioning valve on autopartsonlinecanada but now it's not in stock for my '92 jetta...!!! IIRC the price was around $80-90.

Possum79 · « **Reply #6 on:** September 27, 2008, 08:57:12 pm »

My Bentley actually says something about the same kind of vavle you linked to. It is supposed to run right before the bigger regulator. I didn't look to see if there was one or didn't pay much attention to in the book if it was for something like the caddy.

Definitely thanks for the info!

~Ryan

jtanguay · « **Reply #7 on:** September 27, 2008, 09:12:00 pm »

np. all these proportioning valves are supposed to do is give you bias to the front so your ass end doesn't mis-behave :lol: doesn't matter how do you do it, as long as it works IMO.

i used the resistor off of a bmw for the low speed a/c fan setting... works good and looks to be far superior quality too!

i wonder if it would be possible to fix one of these... i would take it off, clean the heck out of it (and remove all remnance of brake fluid) then somehow glue the rubber boot (if it's not in too rough shape) right to the unit, while making sure it still does its purpose and allows movement.

Dakotakid · « **Reply #8 on:** September 27, 2008, 09:26:09 pm »

Pardon me. I was thinking you were referring to a Jetta prop. valve when you said "in the rear." My mistake.

Possum79 · « **Reply #9 on:** September 27, 2008, 09:51:48 pm »

It appears to be leaking from that center little divit that I cannot see to well. Sorry for the camera phone quality :oops:

jtanguay · « **Reply #10 on:** September 27, 2008, 11:24:32 pm »

wow i should snap a pic of mine... yours looks pristine in comparison! :lol:

i would definitely try taking it off and trying to seal that leak. prepare yourself to bleed the brakes though... so factor in an extra few hours and be sure to catch ANY brake fluid that leaks out, unless you're on concrete as the brake fluid can destroy your driveway. (if you didn't already know all that :wink:)

most if not all the brake fluid should leak right out, but its a really good time to bleed the whole system through anyway.

btw that looks like the one i saw for a volvo... one line goes in and two lines come out???

Possum79 · « **Reply #11 on:** September 28, 2008, 09:36:15 am »

If I remember correctly 3 lines come out. The pictures of the new ones look that way but I may get under there again and make sure. It looks good because I couldnt tell where the leak was from and I clean it up with a shop towel first. I was hoping that it was one of the flare lines that needed to be tightened but I was wrong.

smutts · « **Reply #12 on:** September 30, 2008, 01:30:50 pm »

Be gentle with the pedal if you don't use a pressure bleeder, I've wrecked master cylinder seals on old cars by pushing the pedal so far that it reaches the part of the cylinder that isn't kept clear of rust and grot by healthy exercise. Next you will be looking for a mystery fluid leak whilst the servo secretly fills up with brake fluid. :evil:

juleshs · « **Reply #13 on:** April 06, 2009, 12:25:46 pm »

my 1990 golf doesnt have one and my rear left wheel locks up when i brake hard.do i need to fit one?