Hello,

I have a 97 4 dr civic dx, I did a rear disk conversion, the rear brakes are from a 94 delsol si, ebrake lines from a teg, master cyl is a 15/16's from a 96 teg, and I have the 11 inch brake boaster (i think 11 in, it was from a gsr teg).

The orginal master cyl I put in was the 1in from the teg gsr, but that went bad so I got the 15/16's from Advance autoparts.

Now after I drive for a while the brake petal becomes stiff, then shortly after that there is so much pressure in the lines the brakes will be fighting the engine and would eventually cause me to stop.

I had the fluid filled to the max line and thought the fluid couldnt expand w/the heat so I dumped out about half right between max/min. The system became so pressured I had to pop the rear bleeder valves and blow off some pressure so I could get it home.

The problem started when i put the new master cyl in. I need to know if the problem is a mismatched master cyl of if I have a defective check valve in side the master cyl.

Please HELP.

 

What happened to your brakes exactly? I found your post quite hard to understand. Are you saying that rear brakes froze or what?

 

I put in the new master cyl, test drove up the road (maybe 1 mile max). My sister took the car home (5 miles or so) she got in the next day did a couple of erronds, and had trouble so she calls me.

When I get to the car the brake pedel is quite stiff and really touchy and the brakes are dragging some, so I attempt to drive it about a mile back to her house and the pressure built up so bad in the lines that I had to stop (because the engine was working so hard)...I stopped and waited 10-15min the pedal was still stiff. I got a wrench and opened the bleeder valves to let off the pressure on each of the back wheels. After I closed the valves, the pedal was good so I drove the car the rest of the way to my sisters house.

I go over after work and drive the car home (5mi) and it went fine. This morning I drove the car so I can see if the problem will return, so I did some erronds, and it came back.

The problem is pressure gradually builds up in the brake lines until I cannot drive the car anymore because the brakes fully applied and the engine cannot move it any more. If I stop and open the bleeder valves to release the pressure I can then drive again for a short time.

I used prestone synthetic DOT3 fluid when I did the conversion and the new master cyl, I didn't drain the system 100% but I probably replaced all the original fluid by pushing it out during the conversion and master cyl change. I did the rear disc conversion last summer and every thing was good til the master cyl went bad.

I need to know if I have the wrong combo of brake booster and master cyl which is causing the pressure to build up. If that is not the case the master cyl must have a bad check valve. I don't know the name of the valve but there is one in the master cyl that is supposed to matain a certain pressure in the lines all the time I am thinking that if that valve is bad it may not be regulating the pressure correctly.

 

I didn't read all of your post, because frankly I'm too lazy to read it all, but did you forget to get a proportioning valve from a 94-01 integra. With the new brakes and lines, your brake system doesn't know how to properly send all of the brake fluid. If you already did that, well then I say your screwed and on your own.

 

did you hook up the vacuum line to the brake booster? does the engine run fine like at idle and what not?

 

Thats a really good point and that sounds like something that would cause your problem. Your rear brakes would be getting the same amount of pressure as the fronts, but they are designed to get less pressure than the fronts which will cause a problem. I don't think that a bad check valve could cause the problem b/c if anything it would decrease the pressure b/c the fluid would have somewhere else to go and give less restriction. A disconnected vacuum line will just not give you power brakes, it will not lock your rears up.

 

I did not change the prop valve, but at the same time I have been driving the car for a year or more with the original prop valve. In snowy parking lots I could tell that the rear would lock a little sooner, but in normal driving it hasn't been in issue.

I am also not 100% sure that i have the brake lines hooked properly to the master cyl. The civic one had both on 1 side the teg ones had one one each side, so I had to re-bend the lines.

I am looking at getting the all original master cyl/brake booster from a 97 ex, and going back to stock. I no longer own the car, I gave it to my sister, I just want to make it save and reliable.

 

You should also change the prop valve with the MC and brake booster. Although i'm not sure if the MC and brake booster will fix it.

 

I am getting a MC, boaster, prop valve, and the original lines. I am also going to flush all the fluid and replace it. I can't imagine that going back to the original components wont fix the problem.