Brake pad question

[RL911]

04 986 base. Installed new powerstop evo front pads and rotors a few months ago. Have noticed a clicking sound when at a stop and I lift off the brake pedal. Checked the front brakes and the pads are a little loose as I can move them with my finger against the spring. believe this to be the source of the clicking. The pads were bedded in and have maybe 300 miles or less on them. Is this something I need to be concerned about or anything I can do short of replacing the pads with a different brand. don’t really notice any difference in performance. Thx

[dghii]

Did you use the backing plate when you installed your pads?

[RL911]

Originally Posted by dghii

Did you use the backing plate when you installed your pads?

The backing plate was embedded on the back of the pad, so yes. This is what I installed.

https://www.rockauto.com/en/moreinfo.php?pk=4503648&cc=1428588&pt=1684&jsn=421

[Burg Boxster]

photo of install & video of movement against spring etc. would help diagnose immensely. They should NOT move vertically at all against caliper retainer spring plate once correct pads are installed correctly... only on a horizontal plane in and out against rotor. Even if you release pedal you shouldn't be able to hear any substantive pad movement.

Also, did you:

- re-check all wheel bolt torques? (97 #-ft on 987 IIRC)
- remove any caliper while installing? (if just pads no need on '04 986) check caliper bolts?
- replace rotors (sounds like no)?
- replace any hardware - caliper bolts, retaining spring, retaining pin, etc.?
- apply disc brake quiet (like CRC) to backing plates helping pads stick to caliper pistons?
- use caliper grease as necessary?
- check caliper pistons for leaks and free movement - inner & outer?
- bleed/flush brake fluid system once complete?
- keep an old pad set from each axle around to measure backs against new?

Happy to help - need some more input please.

Good luck

[RL911]

Originally Posted by Burg Boxster

photo of install & video of movement against spring etc. would help diagnose immensely. They should NOT move vertically at all against caliper retainer spring plate once correct pads are installed correctly... only on a horizontal plane in and out against rotor. Even if you release pedal you shouldn't be able to hear any substantive pad movement.

Also, did you:

- re-check all wheel bolt torques? (97 #-ft on 987 IIRC) YES
- remove any caliper while installing? (if just pads no need on '04 986) check caliper bolts? YES
- replace rotors (sounds like no)? YES
- replace any hardware - caliper bolts, retaining spring, retaining pin, etc.? SPRINGS REPLACED
- apply disc brake quiet (like CRC) to backing plates helping pads stick to caliper pistons? YES
- use caliper grease as necessary? YES
- check caliper pistons for leaks and free movement - inner & outer? YES, no leaks
- bleed/flush brake fluid system once complete? No, but I bled them a month or so prior to changing the pads/totors.
- keep an old pad set from each axle around to measure backs against new? NO, it’s been a few months and I tossed them.

Happy to help - need some more input please.

Good luck

thx, see my responses above. Brake performance is good, noise only happens at a stop when I lift my foot off the brake I’ve ordered a better set of pads so will see if that fixes the issue, but I removed and reinstalled the pads this morning and everything looks pretty normal. There is some movement of the pad if I push against the spring, but it doesn’t seem particularly excessive. It’s just a loud click when I roll to a stop and let off the brake. Seems to be coming from front left around mc and the wheel, hard to pinpoint, and I can’t duplicate in the garage. Anything else in that area that could cause the click?

Also, I wasn’t aware a brake bleed was needed after pads/rotors changed since the system isn’t being opened other than removing the reservoir cap. I will give it another bleed after putting these new pads in.

[986tate]

In the Rockauto Powerstop link you provided there is a serial number ending in 737, do yours match it? Ending in 738 is a rear pad.
This Pegasus link shows the dimensions of what an FMSI D737 pad should be

https://www.pegasusautoracing.com/productselection.asp?Product=HB289

[Burg Boxster]

Bleed isn't necessary but ain't gonna hurt (v cheap insurance especially after pushing all that fluid upstream back into reservoir and again down stream resetting pads against rotor. Who knows what in brake lines could've shaken loose. Regardless, trying to help you find cause by understanding all done. Which has me wondering a bit...

- replace any hardware - caliper bolts, retaining spring, retaining pin, etc.? SPRINGS REPLACED

There shouldn't be ANY play b/w top of pads & spring. In fact you should have to push down reasonably on spring in order to get retaining pin & spring cotter pin (stop) re-engaged. The pad 'ears' likewise should be firmly seated in caliper to boot.

Can you post a photo of FL caliper (even thru wheel opening could help). And of course, measure new pads upon arrival against these current pads for sizing.

Did you do anything else to vehicle aside from pads & rotors at same time?

Sounds are really hard to trace seated within... try and get someone to stand outside car next to stop and listen for clicking noise you hear to further narrow source.

Good luck

[RL911]

See pics, nothing unusual to me, but maybe someone else sees something. Confirmed power stops I purchased ended in 737. Can’t seem to post pics so here is a link to four I just took of driver front. Hub spins, nothing unusual, no clicks or odd sounds.

https://share.icloud.com/photos/0f2QhHZ74f0Ru-7ewSNhO6Viw

[RL911]

Just thinking about this a little more and what I think happening is either the brake caliper piston is sticking to the pad and then releasing quickly or it’s the pads themselves when the caliper releases. It does sound like a piston retracting, like a clunk. I’m going to replace the pads, cleaning everything up on the pistons and bleed the caliper a good while and see how it goes.

[Burg Boxster]

thanks for pix and yes, from those posted install appears correct. Looks like small space b/w spring and pad retaining pin which there should not be as previously reviewed. Anywho...

Thus back to pad size specs and "ears".

Anecdotally, apologies I had forgotten about as was ~ 2 years ago but pads were either Centric or Powerstop. Regardless, had issue doing brakes on my truck. 7 of 8 pads were easy peasy. The 8th (well was to be 5th - LOL - until I just grabbed the other to hurry up and finish that corner) wouldn't go into outside of FR caliper for life of me. Then wouldn't go into FL either. Past sunset on a weeknight evening so assumed "operator error" rushing to get job done. Just needs another hit w wire brush, brake cleaner and another gob of caliper grease and it'll slip right in, correct? Nope - but diligently kept up this routine for about 25-30 min. Finally, grabbed my digital calipers and sure enough mounting ears on this pad were a smidge too wide. Gahhhh!! Quick cleanup w a metal file and bingo finally slipped right in.

So, will be curious as to how this set measures out against new inbound front set. Keep us posted!

Good luck

[Burg Boxster]

Originally Posted by RL911

Just thinking about this a little more and what I think happening is either the brake caliper piston is sticking to the pad and then releasing quickly or it’s the pads themselves when the caliper releases. It does sound like a piston retracting, like a clunk. I’m going to replace the pads, cleaning everything up on the pistons and bleed the caliper a good while and see how it goes.

Pad should be sticking to piston pulling it back off rotor. Otherwise pad is free floating and will vibrate make all sorts of noise - braking or not. Apply some more CRC red disc quiet to make sure pad sticks "good" to piston.

Incidentally, many vehicles have compression clips on back of pad which slip into piston ensuring pad travels with.

Good luck

[RL911]

Originally Posted by Burg Boxster

Pad should be sticking to piston pulling it back off rotor. Otherwise pad is free floating and will vibrate make all sorts of noise - braking or not. Apply some more CRC red disc quiet to make sure pad sticks "good" to piston.

Incidentally, many vehicles have compression clips on back of pad which slip into piston ensuring pad travels with.

Good luck

It could be the pad is not sticking and that’s why they feel loose in the caliper,