I was waiting for a Stage 1 upgrade kit for my car from StopTech. It wasn't going to arrive until Monday and there was a 300zx meet on Sunday that I wanted to take my car to. Well, I had already drained the fluid and removed the calipers and cleaned them with brake cleaner so I could paint the calipers. So I decide to go buy more fluid to use for Sunday and fill up the resivoir with DOT 3, the recomended fluid.

I had one person bleed the brakes, another pump the brake pedal, and another pour more fluid into the resivoir as it goes down. Well, we bleed all four corners in the correct order and we still don't have any brake pressure. I figured that if I took it out of the garage and put the brakes under pressure, they would start working. They didn't. I pull back into the garage after a good 5 minutes of driving around with no brakes.

The only way the brakes would work is if I pumped them about 10 times quickly and it would build enough pressure up to stop. But, after about 1/2 a second, the brake pressure faded and the pedal would go to the floor again.

Anyways, I'm clueless as to what is wrong and I'm looking for some help. We've tried everything, including bleeding again. So now, we've bled 3 times...2 times to make sure we did it right. I'm clueless...can anyone help me?

 

Did you make sure all the bleed ports were on tite? Master Cylinder lid shut tite? Also check to see the brake pistons.........make sure you didnt pinch them as this could also cause a leak.

 

you might have the master air bound try pumping it in the normal fashion with a friend in the car except crack the lines going into the master to bleed the master out and then do it after the abs unit.

 

Everything was on tight and there were no leaks. Do you guys think I should just re-draing and refill and see what happens?

 

I thought you were never suposed to actually drain out all the fluid - only replace old fluid with new, never allowing the master cylinder to run dry. I think that once air gets in there, you have problems.

When you install new brake componenets, you should continue to add new fluid as you let old fluid out. This way, you never run the master cylinder dry.

Try calling your local stealership service department and ask a few questions.

 

This sounds like lots of air in the system. Just keep pumping then. No need to drain again, just keep refilling while bleeding lines. When your bleeding the ports tho, does alot of air come out?

Or like Z-Z said, call your service depo and ask them.

 

I think Z-Z has it right. If you actually drained all the fluid and then put in the new stuff you might have taken in too much air into the master cylinder and as far as I know it takes a pressure system to fix that. If re-bleeding doesnÃÕ fix it then a call to the dealer is probably in order though they will most likely just want you to bring it in should be a fun drive with no brakes.

On a side note, I just finished the stage 2 upgrade this weekend and painted my stock calipers silver using G2 paint. Waited over 24hours before driving and then went out to seat the pads. When I finished breaking in the new rotors and pads, I drove on the highway for 30 minutes without using any brakes to let them cool off before returning home. The silver paint is already turning a nice golden color because of the heat. If I were to do it again I would install and seat the new pads/rotors and then paint them later. More work but would have been worth it to keep the silver color I wanted.

 

So we bled the master cylinder last night. The first 10 pumps or so were just air. There was the problem. After bleeding the MC I got my brake pressure back. It's still fading if you wait, but not as quickly. I'm going to go through and bleed the entire system again, doing everything I can. Hopefully that will fix it. Good luck to me.

Any more advice guys? Obviously bleeding the MC helped a ton! So if there's anything I may be missing, I could be done.

 

If you did let all of the fluid drain, then the ABS pump has air in it. The ABS pump has chambers that only open/closed when the ABS is being activated.

So it can only be bled by running the ABS pump in a special mode to force it to move all of the air out of it. You will need to take it to a shop that can put the ABS pump into this mode. Trying it on the street may only get some of the air out, since you need to run all 4 channels in ABS pump, which is very difficult and dangers to try on the street.

For future you should never let a braking system drain dry, for several reasons including this one.

You should only flush the system with fresh fluid, this includes sucking out most of the fluid from the MC before you add the new fluid, I use a turkey baster with a short section of tubing.

 

So I can't do this myself? I can't bleed the ABS? I have to take it to someone else? I was thinking that if I just loosened the places where it connected that I could bleed out the air... ???

 

Also, I would have loved it if someone had told me beforehand not to bleed out the entire system. If you could also explain how to do that, I would greatly appreciate it.

Thank you!

 

The only way I know of bleeding the internals of the ABS pump is using a systems diagnostic tester. Normally this is not needed since air should never get into the ABS pump.

When you are changing the lines or calipers you need to cap them off so the fluid does not drain out. The BBK I got from Stoptech had some rubber caps just for that.

Also the cap on the MC has very small air holes. By opening the MC and placing some plastic wrap over it then replacing the cap will help slow down the draining since no additional air can get in from the MC.

 

This is the way I did it when I did my upgrade a few weeks back... Used a friends shop and lift to install all the lines and rotors and new pads, which cut the install time to less than an hour. I then bedded them in on the way home and painted them the next day, when I could leave it jacked up for hours for the paint to dry. Worked perfect!