Hi all, I posted this within another thread but think it needs its own. So I’ve been having troubles with my passenger front wheel getting hot and smoking in my 88GT. Got new rotors, calipers and pads put on and the problem persists. Shop is saying it is a brake line/hose issue and that the proportionary valve may be bad. Does that sound correct? And can you buy new proportionary valves anywhere? Never even heard of that part if I’m being honest. Thanks.

Have a look at This post in a recent thread.

The proportioning valve directs brake fluid to the front and rear each separately.
If that were the issue both fronts would have the same problem.
I would suspect the brake hose at that corner if the caliper was not the issue.
Have you checked the sliders on the caliper to assure they are not sticking?
Could be the piston too?
I've seen problems with rebuilt calipers in the past that were bad right out of the box.

I had this issue on my 86 gt. It was a clogged hose.
Good luck! Getting out of the car after a cruise and seeing your rotor glowing red wasn't a good feeling.

Yup I’m going to get some new brake hoses and lines from the Fiero store and try and get this fixed on my own. The shop it’s at claims they no longer want to work on it, and I just don’t want to get mumbo jumbo’ed anymore. Hope that’s all it’ll take to fix this and drive already.

...My vote is with the hose scenario. They deteriorate inside, and close up. You've got plenty of pressure to push the fluid through the hose to stop, but when you release the pedal the collapsed hose interior will not relieve the pressure in the caliper...Replace them both, the other side will surely follow...

[This message has been edited by FX (edited 07-13-2019).]

Could be combi valve but more common problem is crap 30+ year old hoses.

OE rubber hoses have 2 main fail issues:
Oil etc attack rubber inside layer and rubber swells shut.
Support bracket gets rusty and crushes the line. careful pry open the bracket. If helps still need new hose.

Do NOT buy Brake Hoses thru TFS and many others.
Get a "Pro Grade" rubber that actually fits the car unlike all SS BS hoses and have newer and much better "rubber" w/ SAE J1401 hose like Raybestos PG Plus and some others.
See https://www.fiero.nl/forum/Forum2/HTML/129208.html

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