Rear brakes moan only when braking while reversing

[Nijasan]

Not a pornstar moan, more like what I envision a bull-dyke would sound like.

Anyways, yeah. When I put the car in reverse and slip the clutch a bit and start moving backwards I can hear a single "click" from the back end, I think I've narrowed it down to the brakes. (seperate issue?)

When I'm actually moving backwards, even down a hill in neutral, and I press the brake pedal the rear brakes will moan. Not a high pitched squeak, but something lower pitched.

I've kinda been planning on rebuilding those rear brake calipers, but I checked them out a few weeks ago and the pistons will turn in fine (easily, even. With normal needlenose pliers, no special cube.) and the piston boots (not sure what the real term is) look to be in good shape.

During normal, forward moving driving my brakes don't make any noises - moans, squeaks, screams, anything.

Any thoughts?

 

[4g63t]

My passenger rear brake does the same thing. I think its frozen, but you said yours are not. /ubbthreads/images/graemlins/confused.gif

 

[4Grim]

Can you tell if your back wheels gather brake dust more than normal?

 

[467]

I have had other cars do this to me. I believe it may be a vibration set up by the pad to rotor contact being the reverse of the normal bedding in when brakes are applied in the forward direction. I don't know why rear brakes seem to be more prone to this than fronts, but that is my experience.

New spring clips that pre-load the pads in the calipers may help. There is also a high temperature liquid silicone rubber material you can buy to apply to the rear of the pads. It will dry onto the back of the pads. That sometimes will dampen the vibration to the point you will not hear it.

Ward

 

[Terry Posten]

Yes, the spring clips are messed up. That will cause the single "click" when direction is changed and cause rattleing/moaning of the pads in certain conditions. You can buy just the clips from Orielly's Auto for around $12.00 a complete set.

They must be used but you must clean all the rust and scale from the pad cradle before you install the clips and the pads or the pads will never fit. If you have to use a prybar or hammer to seat the pads into the cradle, use have not cleaned them enough. I used a dremmel with a small wire brush and went to town.

Make sure you grease the sliders when removed to keep them from locking up 6 months down the road.

Good luck.

 

[Nijasan]

aha, the clips! That makes since because it's very easy to slide the pads in and out in the rear. I greased up the sliders at the beginning of June when it was starting to get hot, but I'll double check them this weekend. No O'Rielly's around here but I'm sure someone will have a set.

I'll report back in a few days.

I guess the clips being loose allows the pads to move around a bit and make the weird noise when moving backwards, so this will solve both problems.

 

[speedyvr4]

put some of this stuff on the back of the pad where the caliper and pad make contact. the goop, not the spray.

 

[4g63t]

I don't think I have those clips - I'll try that too.

 

[CP]

Mine did that for a while last winter, just when braking in reverse, and was a low groan when bringing the car to a stop. It went away, and I attributed it to new pads/rotors or road salt.

You *may* have a caliper that's sticking. Check both for excessive heat after a highway drive with minimal brake usage. Pull over and see if one rotor is considerably hotter than the other side.

 

I have had better luck stopping brake noise by using anti seize on the backing plates & sliders rather than the glue, which I find wont last very long. You do need to make sure all the retaining clips are present though.

Mine did do the exact same thing untill I recently rebuilt my brakes & lubed my previously frozen slider pins.

 

[Nijasan]

In June I got some sil-glyde and re-lubed all the sliders and applied some on the backing plates but I'm going to do check it again tonight.

I picked up some new sets of clips this morning. I also got front clips just to be thorough. It was like $14 for the rear set and $19 for the front set.

edit: I'll also check for excessive caliper heat on the way home from work. I'm a leisurely 8 miles away and there shouldn't be any heavy braking. If the brake pistons turns in at all does that tell me that the caliper is okay? Or can a caliper be messed up yet still be able to turn in?

 

[CP]

No idea. I've never had one go bad on me...yet. But it would make sense that if the caliper was frozen the piston is the part that's fused into the caliper and can't move in/out anymore. Just throwing out ideas here. Wait until someone with experience chimes in.

 

typically if they will retract the caliper should be ok. you may not know for sure though until your test drive.
Good luck

 

I had the same problem a little while ago. My rear passenger side brakes were moaning really bad when i reversed, it was loud. But it also made a noise when i was just braking in normal driving, but alot less moaning. When i starting taking it apart i noticed that the brake pad on the inner side of the rotor was not even there, and the piston was just pushing against the rotor. The seal around the piston was ripped which made it cease up and rust. The moaning sound was coming from the piston pushing against the rotor. You may have the same problem, hope that helps!

 

[speedyvr4]

Quote:
I have had better luck stopping brake noise by using anti seize on the backing plates & sliders rather than the glue, which I find wont last very long. You do need to make sure all the retaining clips are present though.

Mine did do the exact same thing untill I recently rebuilt my brakes & lubed my previously frozen slider pins.



The goop works, I can vouch for it. We use it at work and we have almost zero comebacks and lifetime warranty. What we do is cook it on a heat amp for 15 minutes, then install it. I put the anti sieze before the goop, and after the grease wore off, it just started squeaking again, Now with the goop, no more problms. Thats my expirience. I agree that you have to have all the hardware and also nice and clean and lubed.

 

[Nijasan]

Alright.

I checked the calipers when I got home this evening and I wouldn't even consider them warm. They felt 'room temperature' or maybe 5 degrees above. The muffler, however, was hot. I didn't need that arm hair anyways.

I installed the clips tonight when the sun finally went down. They seem to have cured the moaning, however the clicking still remains.

The clips went on pretty easily. I have one of those 'California Princess' cars, so no rust anywhere at all. I just cleaned off some of the brake dust (not too much on either side, really) and they slid right on. When I seated the pads, however, I could very easily tell a differnce between the new clips and the old worn out ones. They definately now "spring" into place. I lubed the slides on both sides and I made sure the piston lined up with the "nubs" that are on the pads so the brake piston contacts the pads correctly.

Braking feels fine, not much different than before from the laps I did around the neighborhood. Absolutely zero moans or squeaks, though, and that was the main goal.

What else could make the clicking sounds? They happen when I change direction. Like I'll back out my driveway (it slopes upwards) and stop, sit there for a few seconds, put it in a first and go forward, when I start moving forward, no matter how long I've sat there, both sides will 'click'. I'm not sure where the sound is coming from exactly aside from the rear wheel area.

 

[speedyvr4]

Did you use the goop? I sound like my nagging wife /ubbthreads/images/graemlins/tongue.gif. Have you checked your U joints? or the rear axles? Have a friend drive your car in the drive way while you hear for a noise in that area. If you have accsess to a lift, raise that bitch up on all 4's and try and listen to the noise from under.

 

[Nijasan]

No, no goop. I think I need to go back and use it though. U joints? Nah, I've not checked them. Rear axles look OK. The boots are old but no cracks or leaks.

I wish I had lift access.