Possible leaking brake proportioning valve

[lessersivad]

A couple of questions about this. (Yes I attempted a search using quotation marks).

1) Has anyone else had this happen?

I have not done a real thorough investigation, just a simple look-see and it appears my proportioning valve/splitter may be leaking externally.

I've been experiencing a mystery fluid loss for a few weeks now and that seems to be the culprit.

All of the lines (except the front ones) have been changed. Calipers and wheel cylinders replaced also.

I initially thought possible master cylinder leak but removal of the vacuum hose showed no signs of dampness inside. I have not pulled the MC from the booster yet to make sure.

2) Where do I get a replacement besides a used one?

I went on the Russian sight and got the part number, ( MB03743900) Unfortunately Fourgreen doesn't show it.

IF a used one is the only option then so be it. I was simply hoping for a new replacement if, in fact the original is leaking.

[FestYboy]

The proportioning block can't leak internally, so if it's leaking externally, you should easily see it. It has no moving parts so a used one shouldn't be a hang up

[lessersivad]

The proportioning block can't leak internally, so if it's leaking externally, you should easily see it. It has no moving parts so a used one shouldn't be a hang up

I did notice some wetness on the outside of the block but didn't do a real good investigation. If there's no moving parts then i agree a used one shouldn't be a big deal.

Just seems weird it would be leaking unless it's possibly cracked or has a small casting pinhole seeping.

I've been attempting to keep an eye on the fluid level but more times than not, the indicator light comes on letting me know the fluid is low. It takes around 7-10 days for the level to drop.

[bravekozak]

I just checked. E8BZ-2B257-A ,Pressure Metering Valve, is out of stock at all sellers on Rear Counter.

[WmWatt]

Did you remove the wheels and check the backside? Leaks at the cyclinders and calpiers can show up on the back side of the wheels. I'm with Brave on assigning a low probability to the combo valve. Any strange feelings in the brake pedal?

[bhazard]

Does that block actually proportion or just distribute? If it were up to me I'd prolly just replace it with some tee's and prop valves.

[lessersivad]

Did you remove the wheels and check the backside? Leaks at the cyclinders and calpiers can show up on the back side of the wheels. I'm with Brave on assigning a low probability to the combo valve. Any strange feelings in the brake pedal?

I replaced both wheel cylinders, both calipers, all the rear lines including hoses. All is new.

Not really anything strange with pedal feel.

I'll have to investigate further once we get past the snow we're getting. (Snow plowing takes priority for me this time of year...LOL).

IF it is the 'pressure metering valve' I have a couple of donor vehicles out back. I was simply wanting to get a new one if'n it wasn't too 'spensive.

[lessersivad]

Does that block actually proportion or just distribute? If it were up to me I'd prolly just replace it with some tee's and prop valves.

IF it's leaking and I replace it, I may do a 'destructive autopsy' to investigate the innards ...LOL.

[FestYboy]

Brad, 2 in and 4 out from 2 identical ports in the master suggests a metering block. Each port on the master is responsible for a front an a rear at opposite corners.

[bhazard]

So would there be any downside to switching it to a more conventional setup besides being less safe? Lol

[bravekozak]

If you switched to an adjustable proportioning valve. You gain control over the timing of the front wheel lock a split second before the rears. You only lose that little bit of cross proportioning for losers who never check their brake systems until they fail. Adjustable will take into account caliper, suspension and master cylinder upgrades from stock. We need a metric distribution block!
Installation.

[firebush357]

Mine leaked when I first bought my car but I couldn't tell until I had really good pedal pressure. Mine would actually spray about 4 feet in the air once I got all of the air out of the lines and a brand new Master Cylinder. When I took it apart to find out the problem it looked like something got in there a wore a pit in the metal causing it to leak. There is no gasket in there but there seemed to be some kind of glue originally but I'm not sure what you could replace it with that wouldn't be effected by the brake fluid. They are a pain in the ass to get all of the lines off and back on again so be prepared for that.

[lessersivad]

Mine leaked when I first bought my car but I couldn't tell until I had really good pedal pressure. Mine would actually spray about 4 feet in the air once I got all of the air out of the lines and a brand new Master Cylinder. When I took it apart to find out the problem it looked like something got in there a wore a pit in the metal causing it to leak. There is no gasket in there but there seemed to be some kind of glue originally but I'm not sure what you could replace it with that wouldn't be effected by the brake fluid. They are a pain in the ass to get all of the lines off and back on again so be prepared for that.

Yea I'm prepared for the lines possibly not cooperating when the time comes to remove/investigate/more than likely replace.

[firebush357]

Getting the lines to thread back in was just as hard as removing them for me because getting all 6 lines to line up just right to catch the threads correctly wasn't easy. To get them off I would soak them in PB Blaster and invest in a good 10mm Flare Nut Wrench, I've heard that Snap On makes a really good one that doesn't strip the nuts as easy.

[FestYboy]

Snap-on is the only one you want... Used them all and you can't touch their reliability. Pricey? Yes, but worth not having to replace nuts and re-flair the lines.