BRAKE FLUID LEAK!! HELP

proportioning valve

Word of advise...

DONT DRIVE YOUR CAR WITH A BRAKE PROBLEM.

Start by tightening all the fittings and cleaning the fluid off the car. It will eat the paint.
Top off the fluid, start the car and pump the brakes a few times to see if it's still leaking. If not, go for a drive and check again. Do this until you're sure the leak is gone.

time to upgrade to 5lug?

there's an o-ring on the side (towards the front of the car) plug of that block. if you're sure it's not the brake lines leaking, that would be the next likely culprit. although i've never heard of them going bad?

see where the leak is coming from first. either the top, side(s), or bottom. let us know

nos707 said:

Is there a rebuild kit available?

I cant find a replecement valve!

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I don't think there's a rebuild kit. It's not uncommon for them to leak after 15+ years. I think you can buy a new one for Ford. But, they are not cheap (?$80?).

Also, depending on where you live and how/when the car was driven, the brake fittings may be forever rusted to the brake lines. So, you may need to replace brake lines.

SOAK the fittings with PB Blaster a day before. Use a flare wrench. If that won't work, Vise Grips makes a Vise pliers made specially for hex nuts. I've used mine a lot when I'm now doing the rear brake lines on my '92 Olds.

Note: If you get one from the junk yard, it may have the same problem down the road.

Anyone know if PPI sells prop valves? Or, if Ford still sells them for the 87-93 Stangs?

IMHO, *I* would buy a new one before I bought a used one from PPI. But, I know how tight money can be for people. So, I mention PPI.

FYI: From:
Performance Parts | Suspension Parts
1987-04 We have a large inventory of new 1994-04 Cobra suspension parts such as spindles, axles, brake lines, master cylinders, boosters, proportioning valves, hardware and lots more for your brake or suspension conversion projects or race spares!!! Call or email us with your particular needs!!!,

BTW: Why you want an OEM "prop valve", and you do not want to just gut the OEM prop valve and use an add-on external prop valve (especially for a disk/drum setup!).

For a disk/disk system, you can "get away" with using a straight prop valve setup. But, you will not get max braking ability doing just that.


From:
StopTech : Balanced Brake Upgrades

Combining Strategies – The Misnamed Proportioning Valve

Conventional proportioning valves should really be referred to as “braking force regulators” or “brake pressure regulating valves.” While their name might imply true proportional control, in reality they provide a combination of the control found in Figures A and B.
Up to certain pressures, these valves allow equal pressure to both the front and rear brakes (à la Figure A). However, once a preset pressure point is reached (600 psi in the example), the rear brake pressure continues to build, but at a slower rate (or slope) than the front brake pressure. Figure C displays this for us quite clearly.

i think there is a seal you can get for that..

nos707 said:

I have checked all the lines, and im sure its coming from the nut on the front of the valve.

The fluid is leaking on the bottom.

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Uhm, yup. You're right. That's where they leak.

The problem is that the internal "piston seal" and maybe the chamber are bad.

As I said, the only correct way is to replace the whole unit with a new one for Ford.

You can take your chance with a used one. But, "eventually" that used one will also leak. It's based on probability, age, use, etc. A used one may last 10 years, or it may last 10 secs. No way to know. A new one should last 10-20 years under normal use.

People have tried to take the "piston assembly" from a "good used" prop valve, and put it in the orig. That way, you don't have to take off the lines. In reality, only a VERY SMALL percentage have really been successful. There are many real-life reasons with "rubber"/etc why that's so. In general, they end up with 2 prop valves that are now not working. IMHO, that BS assembly will likely leak in a short time.

You have two, and IMHO only two choices,
1) New Prop Valve from Ford. - Preferred.
2) Used Prop Valve hopefully from a low mileage, mostly highway car.

BTW: This is a "common" problem. No big news. Still, I personally know very well how much it can suck for the person that has to do it!

I had to remove my prop valve for my M2300K setup. And, I went and got some 94/95 prop valves that had ABS for my setup from the junk yard. At the junk yard, I saw some prop valves, fittings, and brake-lines that were one happy piece of rust. In my car, two brake lines were rusted forever to the fittings. One was to the MC, so I didn't care. The other was to the back brakes and I ended up replacing that segment.

Good Luck! PB Blaster and those hex-nut vise grips are your best friends on this Earth right now.