Brake Problem with '92 Explorer Sport

[srinda]

I've had my old girl to the mechanic a few times already but still have an issue with the brakes. There isn't enough braking power and I've come close to rear-ending cars. My mechanic replaced the master cylinder and the brake booster, checked all lines, and bled the brakes. He said there may be a problem with the proportioning valve but the brakes do not have the symptom of locking up. There is too little pressure going to the rear brakes he said, not too much. If the problem is the proportioning valve, the part has been discontinued. Does anyone know where to buy an after market valve? Or, can the cause be something else he's overlooked? Thank you for your time.

 

[motohobo]

So you press on the brake and the pedal feels like it has pressure, that is, it doesn't sink down to the floor, but instead of brake you get nothing? No fluid leaks anywhere under the vehicle or below the master cylinder? Is your ABS light on? Consensus seems to be that the 1st gens don't have a proportioning valve per se. It's part of the rear ABS. To confirm that, enter your year and model in eBay and search for 'proportioning valve'. No hits. Search for 2nd gen, i.e. 1995 and after - lots of hits. In those vehicles, the proportioning valve was integrated into the master cylinder, it seems.

But again, I'm no expert and hopefully someone more knowledgable will chime in, but these might help get you started. Always best to search first, you know.

proportioning valve
Brake Proportioning valve??
Need new brake proportioning valve