: brakes slipping?



jgodfrey82
04-21-13, 05:13 PM
Hi Guys, tried searching and googling for general info, but unable to really figure this out yet.

Did my first brake job on my 2007, new pads and rotors from Autozone. Used Cmax (ceramic) pads and their top rotors.

Everything seems great, but now and then getting "slipping" where it feels like they grind a little at the very end of the stop. The stopping power is good and consistent through the stops, but right at the end it almost feels like a slip or grind, and only intermittently.

I "bedded" the brakes right away after install, and everything sounded great throughout, then randomly on a normal driving stop I had the noise.

Tooks the wheels off again last night, made sure everything looked right and tight, test drove for an hour with lots of fast stops and normal stops, no sound, normal driving today, heard it again at the end of a stop.

Any advice for a newbie DIY'er appreciated.

orandaberg
04-21-13, 06:10 PM
Is it coming from any one side in particular? Could be a bent splash shield. You say it only happens at the end of a stop where the car is slow enough to hear it, do you feel the grind in the stop pedal

08SRX
04-21-13, 06:15 PM
I am not sure what you mean with brakes 'slipping'. If it means that you do not always good braking power or resistance, there may be grease on the rotors. It is important that the braking surfaces are completely clean and you can accomplish that by either not handling those surface when you install, or cleaning the areas thoroughly! Also, NEVER apply caliper paint to rotors.

jgodfrey82
04-21-13, 06:35 PM
Orandaberg - Splash guard? As in the metal guides that go into the brake bracket to hold the pads? I am not certain if I feel in the pedal or not, I want to say yes, but nothing dramatic.

08SRX - I cleaned before/during install using brake parts cleaner and a towel, is this enough? Is it OK to open up and reclean the rotor?

orandaberg
04-21-13, 07:00 PM
I have a thread on here called "sounds like a cow bell under my car" eventually I also had a grinding sound as i slowed the car before finally replacing my rotors and saw the splash guard (which is behind the rotor)had a bent tab and would rub the rotor at low speeds and give a grinding no sometimes. There is a picture on the post. If you know where the sound is coming from more or less you can raise the vehicle and spin the wheel. But you use the term slipping as if it looses grip and re grips?
You said you did a proper bed in of the brakes. If for some reason you do have some glaze on the pads, maybe try another bed in. If you have the time remove them and have a look, when you did the brakes I assume the rubber around the main piston was good on the caliper?

jgodfrey82
04-21-13, 07:21 PM
ok, checked your post... will have to get under it and look at splash guard... a little deeper than I have been yet.

The term slipping, yes, it almost feels like it is loosing grip and then regripping, but not until I am already almost stopped... almost feels like there is grease on the rotor and the pad slips, again, I checked and could not see any sign of anything on the rotors. maybe I should take tire off and reclean the rotors with brake cleaner? Is this safe to do?

could it just be that the ceramic pads are not broken in yet? Maybe this will go away with a couple of weeks of driving?

orandaberg
04-21-13, 07:35 PM
there are bolts that hold the calipers in place, these have rubber boots and the caliper moves back and forth on these, if they have no grease or the boots have rotten off and dirt has entered maybe they are not functioning properly, just a thought, make sure the bolts are tight. Again is it all 4 wheels doing this, if you break does it pull in any direction. Fluid level OK. I am no expert but have redone all my breaks and rotors myself so I know each part. Just throwing ideas in the air, others on here are much more knowledgeable about this and hope they step in

conedoctor
04-22-13, 11:46 AM
How did you bed the brakes?

jgodfrey82
04-23-13, 12:18 AM
I believe I bedded correctly.... right after installation, stops from 40-60mph to 10 or complete stop with driving quickly thereafter to cool

conedoctor
04-23-13, 11:36 AM
Much too fast and should not come to a stop.

Q: How do I break-in my new pads?
A: Brake Pad Burnishing/Bedding-In Instructions
1. After installing new brake pads, make 6-to-10 stops from approximately 30-35 MPH applying moderate pressure.
2. Make an additional 2-to-3 hard stops from approximately 40-45 MPH.
3. DO NOT DRAG BRAKES!
4. Allow at least 15 minutes for the brake system to cool down.
5. After step 4 is completed, your new Hawk Performance brake pads are ready for use.

Q: Why should I follow a break-in procedure on new brake pads?
A: Correct brake pad break-in (bedding) is important to assure quality braking performance over the life of the pad. This procedure allows the rubbing
surface of the brake pad to be brought to temperatures, creating a transfer-film layer of friction material to be applied to the rotor surface. This
allows the brake pad material to rub against itself rather than the bare rotor. This increases the stopping performance of the brake pad and can

Q: Can I run cross-drilled or slotted rotors with Hawk Performance brake pads?
A: Yes you can. We do suggest a slotted or solid faced rotor for performance applications. Cross drilled rotors are primarily for looks and as such some trade
offs will occur, such as increased brake pad wear and increased dust.
reduce pad and rotor wear.

jgodfrey82
05-04-13, 01:04 AM
Ok.. so today I think I realized what the original problem was. After not really hearing the original noise for a while, today I started hearing a loose part noise coming from front drivers side. I took the tire off and the caliper bracket was completely loose. I tightened everything back up and seems to have gone away.

My question is.. is hand tight enough for caliper bracket and caliper or should I go borrow/rent a torque wrench? Should any of these bolts be coated or sprayed with anything before install?

Thanks for all the advice, im still happy I did it myself instead of paying big bucks to the dealer.

orandaberg
05-04-13, 04:54 AM
past post



there are bolts that hold the calipers in place, these have rubber boots and the caliper moves back and forth on these, if they have no grease or the boots have rotten off and dirt has entered maybe they are not functioning properly, just a thought, make sure the bolts are tight. Again is it all 4 wheels doing this, if you break does it pull in any direction. Fluid level OK. I am no expert but have redone all my breaks and rotors myself so I know each part. Just throwing ideas in the air, others on here are much more knowledgeable about this and hope they step in

glake89
05-04-13, 11:09 AM
Caliper bracket bolts- 96 ft.lb. and use loctite.

repnatl
05-04-13, 11:32 AM
If you use loctite use the blue kind otherwise you will never get those bolts back off. I've never used it on brakes and have Never had one back out but I've seen it on customers cars