Fox T-Bird/Cougar Forums

Technical => Suspension/Steering => Topic started by: cougarbird86 on August 07, 2017, 09:41:37 AM

Title: Proportioning Valve Thread sizes
Post by: cougarbird86 on August 07, 2017, 09:41:37 AM
So im looking to replace my proportioning valve with little modification as possible. Does anyone know what size the fittings are for all the ports? Or does anyone have any experience with an aftermarket one that bolts right up?
Title: Proportioning Valve Thread sizes
Post by: Vintage on August 07, 2017, 12:42:12 PM
Why the replacement?  Have you already swapped to rear discs or put bigger and better brakes on the front?

I think the prop valves on older Fords used standard threads whereas the later ones (90's and newer) switched over to metric threads. Not sure about that, or the exact sizes, but the Maximum Motorsports website might have some info you can use even though its geared towards the Mustang brake system. The Tbird's hard brake line routing goes under the engine on the K-member rather than along the firewall like the Mustangs did.
Title: Proportioning Valve Thread sizes
Post by: cougarbird86 on August 07, 2017, 02:38:22 PM
I believe the proportioning valve has gone bad (valve stuck) because brake fluid only comes out of the front bleeders. Plus, an aftermarket adjustable one would allow me to tailor my braking distribution since I have skinnies up front and meats in the back. I would like to mail order the fittings and lines along with the valve, so im hoping I could get the exact sizes of threads.
Title: Proportioning Valve Thread sizes
Post by: Vintage on August 08, 2017, 05:21:38 AM
You might want to read this:    http://stoptech.com/technical-support/technical-white-papers/proportioning-valves

Also,  if you have no fluid pressure to the rear wheel cylinders, the master cylinder may be suspect.
Title: Proportioning Valve Thread sizes
Post by: cougarbird86 on August 08, 2017, 06:22:40 AM
Thanks for that info, but not really needed (excuse my rudeness, its early and coffee aint done)

And, I actually just replaced the master cylinder a few days ago. I replaced it because I thought it was the reason for having no brakes. Turns out, no.