I have been going through the brakes on my Rx2 for the last couple of weeks and still have yet to get them where I think they should be. Heres what I have done so far. First the booster seemed to be bad due to the bad braking and engine idle change with brake applied. So I changed that with another used unit.

Then the brakes where still not too good so I put a brand new master cylinder on and thought this would cure it. So yesterday I bled all the cylinders, back and front and thought it was gonna get it. The pedal seemed good when I was done it had a good bit of pressure on it half way down. So I started the car and got ready to take off. The pedal goes all the way to the floor again and wont lock up the brakes at all, it stops the car but takes a second.

Im at a loss really of what it could be other than another bad booster. Any suggestions would be great. And if anyone has a for sure good booster they would sell that would help too.

Thanks
Jeremy

 

check the brake master and see if you're loosing brake fluid. if so, then work your way down the lines and such. If the brake booster is bad, the pedal will be very stiff so I dont think that is the case. LMK

 

check your front pads if your missing the retainer clips they can drop down.

happened to me and my brakes would take 30 feet before i would stop once i found the issue it would stop on a dime lol. keept thinking i had air in the system went through lots of fluid before i noticed the pads lol

 

Hmm, im gonna have to check the pads, I have checked the lines from the master all the way to each wheel and there is no leakage at all. Funny thing is yesterday I blocked off the booster on both sides and it stops better with the booster completely disconnected.

 

stiff pedal?

 

Also check the adjuster rod in the booster. There should be 1/8" clearance between the tip of the rod and the back of the brake master. I had my booster rebuild and the shop threaded that rod all the way in. Car didn't start to brake until pedal was half way to the floor.

Most new master cylinders come with a master cylinder kit. plastic fittings and plastic tubing. Thread the fittings into the master, run tubing from plastic fitting to the brake master fill hole. Push pedal, you can see when fluid starts to move.

You could have a hosed booster too.

 

I'm not sure about old school cars but 7s have a brake booster check valve in the
vacuum hose right before the booster connection. Its job is to only allow vaccum to
suck air out and not allow flow the other way. If its not working the booster might
not do its job because it would lose vacuum.

 

the way it sounds like, its going to be a hydralic issue, or even mechanical, remove the front calipers, and look at the inner brake pads, make sure that the brake pads(inners) are all the way in the caliper bracket, sometimes when the brake pads are replaced, the pads are not installed correctly, one end of the pads are out of the bracket, so it makes the piston in the caliper cocked to one side, and then you have a brake fade, I've seen this happen many times, unless the calipers where replaced at one point and time, and the bleeders are on the bottom instead of the top, bleeders should always be on top , if not, you will never get the air out, let us know what you find