I need to know the facts on the proportioningvalves

I am not familiar with the car. Brake proportioning valve is usually positioned these days above or near the rear suspension.

Brake proportioning can be by g-valve, pressure limiting valve or most often these days by a load sensing limiting valve. The latter is connected to the rear suspension by a spring and/or an adjustable link. In some cases there are two valves; one each side for independent rear suspension.
The checking and adjustment of the linkage is generally part of the routine maintenance and is often maladjusted by ill-informed but well-meaning people.

I have seen the g-valve fitted on the front bulkhead by some manufacturers. In theory this type can be fitted almost anywhere.

Mary, PLEASE be sure this looks like your motor even thoe its a 2.3 it still should be the same valve cover .if its not let me know an i'll look further . if this helped you please let me know.
Woody

there only 2 ways (USA answers)
they have a guage test (expensive gauge)
or replace it ,if in fact you know for sure the rear brakes are good.

i think raybestos sells this.valve rebuilt.

the valve is height measuring disconnect the link and see if its
free? is it jammed? i had a 88 from new.
i purged brake fluid every year and it lasted for 250k miles. and sold it.
so there is a bench mark on life.(best case)
did you read the fsm? yet
id does cover these tests.

try alldata.com (usa ) it may cover Commanche.

Usually if the car has a valve it is mounted on the firewall. But your master cylinder has 4 connections, one for each wheel. So I doubt your car has a separate proportioning valve. You could check with the dealer to verify.

Hmm, well you're not telling us much like the make model year? Anyway to take a stab at it you may have a bad master brake cylinder or even a bad proportioning valve. Check to see if you have pressure at the proportioning valve. If so then the master cylinder is fine and your proportioning valve needs to be replaced. But if there isn't any pressure there then of course it's your master cylinder. But again since I don't know anything about your vehicle I'm assuming it's an older one with a standard type of braking system. As you get newer then you get into much more things that could go wrong.

Its usually part of the master cylinder.

1985 lincoln towncar parts will work

All bleeding is done at each caliper and wheel cylinder. The proportioning valve has no bleeder. The proportioning valve makes the front brakes engage before the rears do to prevent the rear brakes from causing a sideways skid.

It could be but I would suspect that the left side caliper is seized and not working. This would case the proportioning valve to send the extra pressure to the right wheel, locking it up Hope this helps.

http://www.bustedjeep.com/projects/yjbrakes.asp

Check out the last paragraph, re: which proportioning valve should I use?

It says that either will work, but the YJ valve is cheaper