Hello, I’m posting this question in regards to my father’s 2001 Nissan Quest. He is having issues with his brake pedals getting stuck.
Description of problem: When we pump the brakes they get high, when held down they remain high, but when released and pressed down again they will go to the floor. Brakes were pumped up and vehicle put on a 2x4 and left for a week but still remained high. Checked again for leaks but none observed. When 2x4 was removed and brakes stepped on again they went to the floor.
Previous fix attempts: Replaced master cylinder, rear wheel cylinder, caliper, and brake lines, bled all lines + vacuum bled, reverse bleed, checked for air or leaks in the system. Thanks in advance.

Welcome to NICO Club!

Bleeding the brake system is pretty much the solution for the issue you describe in the pedal. Replacing the whole system seems like what you have done, so double checking all of that work probably needs to happen.

Finally, I don't see mention of replacing the ABS actuator and control pump. Don't you have ABS? Have you thought about diagnosing that unit? You could use the Factory Service Manual for that. Actually, you could use the FSM for diagnosing any and all of the brake system issues you may be having. Everything about brakes is here:
http://www.nicoclub.com/service-manual? ... 1_Quest/br

Thank you for your response. He told me that he changed the ABS modulator but I will have to ask him about the control pump.

centralcoaster33 wrote: ↑

Wed Sep 27, 2017 12:58 pm

Welcome to NICO Club!

Bleeding the brake system is pretty much the solution for the issue you describe in the pedal. Replacing the whole system seems like what you have done, so double checking all of that work probably needs to happen.

Finally, I don't see mention of replacing the ABS actuator and control pump. Don't you have ABS? Have you thought about diagnosing that unit? You could use the Factory Service Manual for that. Actually, you could use the FSM for diagnosing any and all of the brake system issues you may be having. Everything about brakes is here:
http://www.nicoclub.com/service-manual? ... 1_Quest/br

I showed him this post and he informed me that he did indeed change  the ABS actuator and pump.

Well, to be honest, I'm not sure what the issue is. It sounds like you've replaced darn near every part of the brake system. Since new parts tend to be reliable I suspect something is up with the labor performed (no offense to the mechanic). There is a bleeding procedure outlined in the FSM brake chapter. Maybe do that all over again and see where things stand...

Just remembered, brake booster! If you're booster has a leak or broken diaphram, this could be an issue causing pumping of brakes to be needed. That could be the vacuum line to the brake booster having a leak (common issue, though you usually get a rough idle paired with that problem). See about diagnosing the brake booster.