Loose backing plate - brake pad

[Chester11]

Hey folks:

Just curious if anyone has had a similar problem. Long story short - I found a loose backing plate / spacer on a brake pad I installed a few months back. It's the rear inboard pad that connects to the piston via a stud. (The piston rotates rather than compressing, so you slide the pad into a slot in the piston).

I'm not sure of the cause - but I also installed a rebuilt Raybestos (from NAPA - not a sponsor) caliper when I changed the pads. (The old piston was seized). The pad is definitively loose in the caliper bracket. Is it possible that when remanufacturing they removed too much material from the caliper bracket and caused the problem?

As near as I can tell, the extra flex is pulling the pad from spacer. Everything else is tight, and the caliper is installed correctly and working otherwise.

Unless I want to replace the whole assembly again, it looks like the only option is a reman Dorman caliper bracket.

Any advice appreciated....

 

[Hall]

Is it a backing plate or a shim ? Shims will be "loose".

 

[user52165]

What car and year are we talking about? Front or rear?

 

[Chester11]

I'm sorry folks - 07 Mazda 6i. Rear inboard pad. As far as I can tell its a shim attached to the backing plate. Usually they are tight to the pad (this one clicks).

 

[diyjake]

Maybe it wasn't installed securely? How long has it been since you or someone replaced the brake pads?

 

[Chester11]

it was last fall, so maybe 6-8 months. I was thinking that maybe I just didn't tighten the caliper bracket down. but everything was tight and the clips were still in place.

 

[user52165]

http://www.hsfmanual.com/rear_disc_brake_components_and_components_location-524.html

Not your car but best I could find quickly. Do you mean the pad retainers - #7 - are loose?

Are the pads are loose in the retainers? Do you even have retainers?

Rebuilt calipers usually suck. Universal applications rather than specific for your car.

 

[Chester11]

Originally Posted by user52165
http://www.hsfmanual.com/rear_disc_brake_components_and_components_location-524.html

Not your car but best I could find quickly. Do you mean the pad retainers - #7 - are loose?

Are the pads are loose in the retainers? Do you even have retainers?

Rebuilt calipers usually suck. Universal applications rather than specific for your car.


The pad retainers are tight to the carrier, but there is still a lot of room for the pads to move in the retainers. My theory is that this extra play loosened the shim (causing the popping noise that got my attention).

I have a new set of pads, I may just buy an OE carrier / bracket if I can find one.

I try to buy new when I can, but the cost here was just too much, and I rolled the dice on rebuilt.

Unfortunately this is the 2nd NAPA part I have been burned on in the last year.

 

[diyjake]

Originally Posted by user52165
http://www.hsfmanual.com/rear_disc_brake_components_and_components_location-524.html

Not your car but best I could find quickly. Do you mean the pad retainers - #7 - are loose?

Are the pads are loose in the retainers? Do you even have retainers?

Rebuilt calipers usually suck. Universal applications rather than specific for your car.


I think he is talking about #5 in this picture.

 

[lbhsbz]

Typically in the caliper rebuilding process, the bracket is only blasted/cleaned...not remachined in any way.


It's possible that a new aftermarket bracket that was made wrong or the wrong bracket was included in the caliper, or that the pads or hardware are wrong. Do you have part numbers?

 

[Chester11]

Number 5 is causing the noise. The whole pad is loose in the carrier. The diagram is pretty close so thanks for that. Only difference is a stud that slides into the piston. The extra play causes the inner pad to pivot on that stud.

I can't see part numbers from the rebuilt parts - everything was painted up. They show the fordmoco markings like the old.

I compared the parts when I put them on. But it was a rush job in the middle of the night. In the dark.

I'm going to take off both sides. And compare.

 

[The Critic]

I have had this issue happen multiple times recently. I don't think these rebuilders are checking pad fitment very carefully on the brackets. Keep in mind that these brackets may have been ground by the previous user to remove rust and therefore, the pad fitment is now wonky.

You can always warranty the caliper and only use the bracket. Just send back the new/rebuilt caliper with your old bracket.

 

[Chester11]

Thanks Critic. I didn't think to warranty just the carrier. For some reason I assumed they would want the entire assembly. I'll see what they can do.

 

[Chester11]

update here - I cannot warranty only the caliper bracket - they want the whole caliper off the car so they can send it back.

so waste a good part of the afternoon wrenching and driving back and forth, for another so-so fit, or order the new part online? I think I learned my lesson and will go new.

I don't know how some of you do this for a living. I can't imagine having to tell a customer sorry - not only does the original not fit, leave your car for a bit, the new part might not either. I get that the shop buy a ton of parts probably receives better service over me, but come on, what a waste of time.

 

[The Critic]

No, here's what you do:

Report the caliper as defective. They will send another caliper with a new bracket.

Use the "new" bracket that comes with the replacement caliper. Do not change your caliper- just send back your defective bracket and the new caliper.

 

[bdcardinal]

Originally Posted by The Critic
No, here's what you do:

Report the caliper as defective. They will send another caliper with a new bracket.

Use the "new" bracket that comes with the replacement caliper. Do not change your caliper- just send back your defective bracket and the new caliper.


Yup this is pretty common.