Fox T-Bird/Cougar Forums

Technical => Suspension/Steering => Topic started by: ZondaC12 on May 20, 2009, 04:56:04 PM

Title: Leaking proportioning valve?
Post by: ZondaC12 on May 20, 2009, 04:56:04 PM
Looks like the front of the valve is leaking...is that nut supposed to adjust it, just out of curiosity? I cant find em on Advance Auto's site...do I need to hit a yard? What else interchanges...just any non-ABS fox vehicle, or is it a little more specific?
Title: Leaking proportioning valve?
Post by: thunderjet302 on May 20, 2009, 05:14:22 PM
Leaking? Really? Hmm I don't think that nut on the front is for adjusting it. IIRC removing that nut allows you to gut it and then use an adjustable proportioning valve. I think that a stock replacement one is going to involve going to a junk yard.
Title: Leaking proportioning valve?
Post by: Masejoer on May 20, 2009, 05:41:07 PM
Do you mean the front that has no lines going to it? The actual valving is inside there but I don't think I've ever heard of it leak. I agree that a replacement is likely junk yard only but more than that, I don't even see how it would be leaking without physical damage to it. The fluid goes in the top and out the bottom with an orifice within the "valve"/block to regulate how much fluid gets sent down to the bottom. I don't have the pictures readily available but they are out there and show the inner workings.

It can probably just be resealed but since air can get into the lines now, it's probably a good idea to bleed the entire system or air
Title: Leaking proportioning valve?
Post by: ZondaC12 on May 20, 2009, 05:51:34 PM
Yeah the big nut on the front...one day I checked the fluid because I dont very often but say once a month or so it will occur to me and it was VERY low. I filled it up and noticed the next day some drops on the street, and as far as I can tell its coming out that front end. Ill clean everything and make sure but it sure looked like it originated right from that piece.
 
My lines are all fine, no rust, nor are any bent for whatever reason or broken, as I said Ill check into this but if I have to replace it what else has the same valve, few yards around here have thundercats.
Title: Leaking proportioning valve?
Post by: thunderjet302 on May 20, 2009, 06:12:03 PM
If it is the valve let me know. I usually go to the yards around here every 2 weeks or so in the summer so if I find one I'll let ya have it for what ever it costs.
Title: Leaking proportioning valve?
Post by: Masejoer on May 20, 2009, 08:44:22 PM
Okay, here's information. As you can see below, there is a simple oring used to seal the front thread. You will need to replace it and bleed the brakes.

The stock block:
(http://home.comcast.net/~seekproj/pvalve1.jpg)

The internals removed:
(http://home.comcast.net/~seekproj/pvalve2.jpg)

The internal workings:
(http://home.comcast.net/~seekproj/pvalve3.jpg)
Title: Leaking proportioning valve?
Post by: Thunder Chicken on May 20, 2009, 08:47:25 PM
I had one leak before in my '87 Sport, and it was different than the one Seek posted. Mine had a rubber bit in the center of that big bolt, and it was leaking at that rubber bit. I just replaced the bolt with one out of a junkyard proportioning valve (it was much easier than trying to free up all the brake lines/fittings)
Title: Leaking proportioning valve?
Post by: ZondaC12 on May 20, 2009, 09:18:23 PM
YES Ive got some black thing in the center...it must be that. Thunderjet, theres one place Im gonna try but if it turns up nuthin Ill let ya know so you can go grab me a new....bolt :hick: haha
Title: Leaking proportioning valve?
Post by: thunderjet302 on May 20, 2009, 09:22:21 PM
Ok. I know the yard by me has an 80 or 81 Fairmont Futura Coupe and a couple of 87-88 5.0 Mustangs so I bet I can find the thing :hick:
Title: Leaking proportioning valve?
Post by: thunderjet302 on May 20, 2009, 09:25:00 PM
Oh wait which bolt? :hick:
Title: Leaking proportioning valve?
Post by: ZondaC12 on May 20, 2009, 09:58:53 PM
Haha it's that very first picture that Seek posted...that big guy on the very front of the block.
Title: Leaking proportioning valve?
Post by: thunderjet302 on May 21, 2009, 11:47:20 AM
Ok I'll see if I can pocket one from a 5.0 Mustang at the yard ;)
Title: Leaking proportioning valve?
Post by: badbird on May 21, 2009, 05:35:05 PM
I have a prop valve off my car in good shape low miles, $20 shipped

Ron 734-776-5987
Title: Leaking proportioning valve?
Post by: 88FoxBird on June 03, 2009, 07:24:14 PM
I had the one in my 78 Grand Prix spring a leak and have an internal issue resulting in no brakes.