1995 Civic Brake Problem: Possibly Proportioning Valve

[scottroll]

Hello. I am a new member to this forum, but a long-time Civic owner. I recently replaced the front brake pads on my stock 1995 Civic DX. After completion, I quickly realized that I had no pedal, which seemed to be a classic case of air in the lines (I had accidentally taken the brake on the FR caliper, so I was sort of expecting it).

I tried to bleed the brake system, using the classic 2 person method, but to no apparent effect. No air or brake fluid came out of the release valve. The fluid reservoir is and has been completely full, no lines were obviously kinked/damaged, and I was having no issues with my brakes prior, so I was at a loss. I took the car to a local shop, where a friend works, to see if they had any ideas. They of course tried to bleed the brakes, on all four calipers, but they had the same experience that I did: no fluid, no air, nothing.

The mechanic said that the Proportioning Valve which distributes the brake fluid could be bad, resulting in no fluid reaching the calipers. This PV is mounted to the firewall, roughly in the middle, and has a number of metal brake lines attached. Is there a way of troubleshooting this valve in order to either eliminate it as, or confirm that it is, the problem? Or are there any other suggestions as to what could be the culprit?

If it is the PV, I believe I can find one at a junkyard for a halfway decent price, but from what I've seen, it would cost around $200 new, so I want to be reasonably sure that it will fix the problem. Any help would be greatly appreciated.

 

[b16lewis]

Busted master cylinder, those valves just don't go bad.

 

[scottroll]

**UPDATE**

I just got a call from the shop that I had look at the brakes, basically calling to say that they have given up. This is a shop which claims to have a mechanic certified in brakes. Of course, it's the boss, so who knows if he really knows his stuff. They have been working on it for a couple of days, and claim to have eliminated the master cylinder, brake booster, and proportioning valve as the culprit. They say they eliminated those components by taking certain brake lines loose and seeing that fluid was being pushed through, but there is still no fluid reaching any of the 4 calipers.

They said that the only other possibility is that I got the entire brake system full of air and the entire system has to be flushed, which requires a special machine. They referred me to another shop in town which they claimed had the machine...they don't. But I guess I will take the car to them, or someone else, tomorrow to have them look at it.

Any other suggestions? Thanks again for the help. (Please see my previous reply below as well)


Thanks for the reply. I know the master cylinder or brake booster is certainly a possibility, but it just seems too coincidental that everything was fine with the brakes prior to the replacing of the front brake pads (other than the pads being perhaps overly worn out), and now have the master cylinder or booster suddenly be bad. If the MC was bad before, what would have been the symptoms? Booster? There was plenty of pedal and the car stopped fine, but the brakes did sound kinda bad, which I chalked up to just worn pads. Is it possible that pushing the pistons back in could have messed up the MC, booster, or proportioning valve somehow? Thanks.

 

[Pr loco]

I had the same exact problem with a Toyota Celica I had. All 4 brakes worked fine all I was doing was a routine brake change however when I put everything back together and tried to bleed the lines with the 2 man way, there was no air, no fluid comming out . It was the stupid ass Proportioning Valve lol. Although I am no master mechanic, I'm almost positive thats what went bad in your car. good luck