Questions about brakes..

[ohthejosh]

Would air in the the lines cause a piston to stay extended and not retract when the pedal is pushed?

In turn causing the pad to be in contact with the rotor constantly creating a scarping sort of sound.

I just changed all rotors and pads on my car but have yet to bleed the brakes since I'm not confident enough to mess with that fluid just yet.

[110stx]

The short answer is: No.

The long answer would be: Recheck your work. Ensure that all rotors are seated properly on their hubs, that all pads are installed correctly (springs seated properly in front, friction surface facing the rotors), and then doublecheck to see that the back plates aren't contacting the rotors.

And I have to comment on the irony ... You changed the brake parts, but aren't confident doing a brake bleed???

[ohthejosh]

I heard the fluid is highly toxic and corrosive, I am a bit clumsy with stuff like that and really don't want to take the chance with it until I understand the process 100%. Rotors and pads aren't as hazardous.

I will re-check the seating and Im pretty sure its just the rear. Thanks for the help!

[fronton]

I heard the fluid is highly toxic and corrosive, I am a bit clumsy with stuff like that and really don't want to take the chance with it until I understand the process 100%. Rotors and pads aren't as hazardous.

I will re-check the seating and Im pretty sure its just the rear. Thanks for the help!

ha, brake fluid is not hydrochloric acid. Yes, it needs to be kept away from your paint since it will eat away as well as thinner would but that is about the extent of the danger. You can get it on your hands, the calipers, the ground... just make sure to rinse it off well when you are done. Or use latex gloves if you want and try not to spill it everywhere. I'd rather work with brake fluid than power steering fluid any day.

[ohthejosh]

ha, brake fluid is not hydrochloric acid. Yes, it needs to be kept away from your paint since it will eat away as well as thinner would but that is about the extent of the danger. You can get it on your hands, the calipers, the ground... just make sure to rinse it off well when you are done. Or use latex gloves if you want and try not to spill it everywhere. I'd rather work with brake fluid than power steering fluid any day.

Learn something new everyday :D Still learning how to do everything myself, sounds like something I'll be doing soon.

[jlevie]

A scraping sound from a wheel, that goes away when you touch the brakes, is probably a sticking caliper. The fix for that is to rebuild or replace the calipers.

[bmwguy325is]

A scraping sound from a wheel, that goes away when you touch the brakes, is probably a sticking caliper. The fix for that is to rebuild or replace the calipers.

This and our you forgot to lube the caliper pins on the caliper seat. Or you wore on pad down more than the other same reason.

[hamilton325i]

ha, brake fluid is not hydrochloric acid. Yes, it needs to be kept away from your paint since it will eat away as well as thinner would but that is about the extent of the danger. You can get it on your hands, the calipers, the ground... just make sure to rinse it off well when you are done. Or use latex gloves if you want and try not to spill it everywhere. I'd rather work with brake fluid than power steering fluid any day.

And I'll take P/S fluid over gear oil until the day I die ;)



First step: pull the wheels and verifiy which corner is causing the issue.

When you pressed in the piston on that particular caliper did it go in noticeably rougher (take more effort) than the others? If it did I would agree with the other sentiments as a stuck caliper.

If it felt normal going in +1 on I would definitely verify your caliper slides are well lubricated.

If you have a good deal of air in the system you would most likely feel a difference in the brake pedal before anything else.

Did you open any bleeders? If you didn't actually open the hydraulic brake system there should not be any significant air pockets unless there is a failure somewhere else.

Good luck to you!

[ohthejosh]

I havent done anythingnyet but movebthe car to a different parking spot and pumped the brakes a few times now one side is considerably less noisy, hopefully all i need to do is clean and lube.

Jlevie,

Ive seen your response in regards to ebrake adjustment, is the any pictures to accompany those instructions? My e brake doesnt work at all after put the rotors on.

[e30conv2]

Just like 110STX said check over all your work. Also did you make sure your guide pins on the calipers are sliding properly? This can be an issue also. I always clean & relube the pins with Plasticlube best stuff out there for moving brake parts.

[TobyB]

It's also not uncommon for the pads to make noise on new rotors-
the seals are designed to hold the pads very close to, but not exactly squeezing,
the rotors. So after a parts change of any kind, it can take a little bit of use
to get things realigned properly.

The check for a sticky caliper's easy- go for a bit of a drive that doesn't use the
brakes much, then check the rotors- they should be uniformly cool. If one's a lot
warmer than the rest, chances are it's sticky.

And brake bleeding should be done at LEAST every 2 years- here, where it's wet and
I tend to do track days, I do it annually at least.

t

[AndrewBird]

It is also very common for disk brake pads to drag very slightly. Not enough to slow the car or anything, but enough that they might make noise at slow speed or if turning the wheel by hand.

[ohthejosh]

Decided to buy new rear calipers. Should be in today or Monday. Hoping the scraping goes away after install and brake bleed.

Thanks for all the responses.