No pressure in brakes...

[Mikeyman64]

Hey zoomers,
I just changed the pads/rotors and painted the calipers on all four wheels of my 02 P5, and now I have no brakes pressure. The pedal will go all the way to the floor if I push it once, but if I pump it a few times it stiffens up. After it stiffens, if I let it sit for a second or two it depressurizes again. I've tried bleeding all four calipers using this guide twice. My clutch still works fine so I know the MC is okay (not to mention it's brand new).

I do have one unprofessional hypothesis. When I removed the calipers to paint them, I left the part with the piston in it to hang from the lines (probably not wise). I thought this could have damaged the lines, but there are no signs of leaking.

Other than that, I had to take the rear driver caliper completely off, disconnecting the brake line to get the piston back in. And I also accidentally popped both front pistons all the way out of their calipers. Those are the only abnormal things that occurred in the process.

Any advice would help! I'm stuck (gratefully) with a buddies Grand Prix for the time being... *shiver*

 

[slavrenz]

Obviously, double check your lines to make sure there are no visible leaks, especially where they go up under the car and you can't see them easily. An unprofessional guess on my part would be that you ruptured the inner brake line when you let the caliper hang, and it is leaking between the inner brake line and the outer covering.

Does your brake fluid level keep falling when you push the pedal? If not, then your problem is not a leak.

 

[P-Funk!]

If all above checks good - it really sounds like a bad master cylinder. The new one may be bad from the store (not impossible).

 

[pro5turbo]

I had a leak from one of my calipers, so being that the car was 6 years old at the time, I replaced all 4 calipers, but during installation and brake change process, it's very crucial that you never let your calipers hang from the brake line or to let the brake line bend too much at any point in time. It's always a good practice to make sure the brake line is comfortable at all times, and you set the caliper on top of the rotor.

If you are obviously not leaking any brake fluid anywhere, and your MC is full, then you probably crushed the brake lines leading to your calipers, and then the pressure is leading back to your MC after a few minutes.

 

[TheMAN]

it's obvious you didn't bleed the brakes enough and still have air in the lines

because you had your s*** disconnected for so long, you let the master cylinder go dry and that takes a LONG time to get the air out!

did you start from the rear PASSENGER (right rear) side like the guide says? if you mixed this up, then it's time to learn what's left and right of the car is and do it right

you're going to need a quart of brake fluid and use ALL of it and make sure there are ZERO bubbles coming out

and don't use the cheap s***, it's only going to make your life harder... get something decent (that you can easily find at the parts store) like prestone, castrol, or valvoline

 

[flash75]

"And I also accidentally popped both front pistons all the way out of their calipers."

Are you sure you got the pistons installed into the calipers correctly? If not sure you need to check the assembly.

Clifton

 

[Mikeyman64]

Okay, I officially feel like a dumba$$.

I was bleeding with the wrong bolts. I was using the bolts that secure the brake lines to the caliper, and not, harder to see ones that look like grease gun nubs.

Thank you all for the feedback, I hope this thread can be of some use to someone.

 

[P-Funk!]

Takes a big man to admit the mistake (and a smart one to learn from it ).

There was a brilliant thread 'awhile ago' on 'stupidest stuff/mistakes made'. You won't feel lonely...