02 AWD 197,000 miles

I replaced all four rotors & pads, front calipers & mounting brackets. Bled system.
Pedal won't come up. When I test drive, in order to get full braking power, I need to pump the pedal.
I never had this issue before.
Any suggestions??

 

Let me start by saying that I only do some work on my own cars (i.e., I have limited training and experience).

I found out the hard way on a previous car that bleeding brake fluid by pressing on the brake pedal can expose the master cylinder seals to a section of the system that is normally not used and probably the corrosion there. Anyway, this type of brake fluid bleeding can destroy the seals in a master cylinder.

I now only bleed brake fluid by pulling it out of the slave cylinders by vacuum.

 

It certainly sounds like you still have air in the system. What method are you using to bleed the system?

I've heard the same thing, and it's the reason why I'm reluctant to do a brake fluid bleed.

There is one way to try and prevent it, the person who is pressing on the brake pedal, should keep one foot under it so that when the other person opens the bleeder valve the pedal won't go straight to the floor, but rather on-top of your foot and will prevent it from damaging the master cylinder. < I didn't explain it very well, but I hope you get the picture.

 

It looks like there is still air in the system.

Salim

 

Ive bled the system on this vehicle the same way every time I change the brakes; I use what some call a one-man bleeder system; basically a tube that fits over the bleeder valve which captures the fluid in a container and does not allow air back in. Has always worked like a charm. The only difference this time is the front caliper replacement.

I doubt the master cylinder is damaged. I believe I would not get pressure at all if it were.

 

Do put the tube to prevent the air going back, but still use 2 person method. Single person with the tube takes a bit longer to get the air our. You can even try gravity bleed . Obviously the vacuum assist or master cylinder reservoir pressure are better (only if you have the equipment)

Salim

 

I've always used this system with no problems but this is the first time I've changed the calipers. Is it your opinion that there is possibly still air in the calipers?? Also, do you suggest bleeding with the engine running?? I've always bled without engine running.
Thanks for everyones help

 

No need to run the engine, but you do need to push a bit of volume of fluid through pedal stroke, so I still suggest 2 people working it and the person below tightening the bleeder during upword stroke and loosen only after pressure is built with downword stroke.

Absence of air bubbles at the bleed point is one indicator, but the back-pressure of the pedal is the best indicator of good bleed.

Salim

 

Thanks Salim. I'll try the two person bleed. Perhaps there is some air in the new calipers that is not getting forced out using the one person method.

 

Well I tried bleeding again with an assistant and still have low pressure. Decided to take car into my local mechanic. They pressure bled the entire system and now its back to normal.

 

Not trying to insult your intelligence by any means, but did you start off by bleeding the caliper farthest from the master to the closest caliper?

 

Yes we did. We must not have flushed enough fluid thru the system. Anyway, $90 to fix my problem, I'm OK with that. Thanks for everyones input