2002 Protege5 No Brake Pedal Pressure

[DaveLarose]

Hi, I have an odd problem.

I replaced my rear callipers and rotors and pads recently, and then bled the brakes. Which seemed to work fine. I replaced all the aforementioned only because it was time, there was no other brake issue.

After a week of driving the car brake pedal became slow and would exert regular pedal pressure after a second pedal pump. I have re-bled the brakes several times now, to no avail.

Weirdly what now happens is when I bleed the brakes; we push the pedal until it pressurises up (engine off), then hold the pedal, open the bleeder, wait until the pedal sinks to the floor, close bleeder, repeat, etc. After several of the actions the pedal gets correctly firm feeling, and then after doing an extra pump or two to make sure that all the air is purged, we totally lose pedal pressure agin. WE repeat this on all bleeders, each time at the start of the process, there is a bunch of air, then no air, good pressure, then no pressure. I keep topping up the fluid to ensure the MC stays full.

We have bled in the furthest to closest manner, etc.

We have tried this a couple of times now. Very frustrating.

Any thoughts would be greatly appreciated.

 

[dragosurf88]

Not 100% certain, but three thoughts come to mind.

1. Bleed the Brake Master First (normally you wouldnt have to do this unless you replaced the Master Cylinder, but just in case air is in the Master somehow), this will require a Master Cylinder bleeding kit. You might be able to get one at an Auto parts store, but the kit usually comes with a new or reman master cylinder. You can bleed the master on the car. You will have to unscrew the brake lines from the master, then connect the kit to the master, loop the lines back into the top of the master, with the lines submerged in the fluid which will be in the master cylinder. Pump and Pump, maybe have another person check to see if any air is coming out. after the bleeding, reconnect everything and then bleed the lines. Start with the furthest corner at the back, and so forth.
2. What the condition of your brake lines? Questionable? Replace them and rebleed the brakes.
3. Possibly a bad master cylinder.
4. check this link for a possible diagnosis -Explains how to test your master cylinder http://www.agcoauto.com/content/news/p2_articleid/266

 

[DaveLarose]

Not 100% certain, but three thoughts come to mind.

1. Bleed the Brake Master First (normally you wouldnt have to do this unless you replaced the Master Cylinder, but just in case air is in the Master somehow), this will require a Master Cylinder bleeding kit. You might be able to get one at an Auto parts store, but the kit usually comes with a new or reman master cylinder. You can bleed the master on the car. You will have to unscrew the brake lines from the master, then connect the kit to the master, loop the lines back into the top of the master, with the lines submerged in the fluid which will be in the master cylinder. Pump and Pump, maybe have another person check to see if any air is coming out. after the bleeding, reconnect everything and then bleed the lines. Start with the furthest corner at the back, and so forth.
2. What the condition of your brake lines? Questionable? Replace them and rebleed the brakes.
3. Possibly a bad master cylinder.
4. check this link for a possible diagnosis -Explains how to test your master cylinder http://www.agcoauto.com/content/news/p2_articleid/266

Thanks, I will look at that idea...