Braking incident - requesting opinions

[ClawSS]

All car guys like a good bench discussion on what some other guy needs to do, so here's a good one.

I am looking for opinions on where to begin my interrogation of my 2010 Camaro SS braking system due to a braking issue that I have been experiencing.

Background:

2010 Camaro SS with Brembo 4-piston calipers front and rear. They consist of the OE rotors and actually with only 26k miles, the OE pads. The car is lowered about 1.25" from stock and has about 1 degree of negative camber in front and

Symptoms:

When riding at speed for a period of time (between 10-20 min.) I will get a severe shudder from the front end when I initially apply the brakes. It does not have to be a panic or aggressive use, but the shake is quite unnerving and felt in only the steering. If I immediately release and reapply, the shake is not present and I experience the expected grip that is Brembo. I can no longer recreate that situation unless I spend about the same amount of time without applying the brakes, but requiring speed, not just coasting for 15 min.

There is no ABS feel of activation (push / pulsation) in the pedal, so I am not certain that the ABS sensor is faulty.

Possibilities:

Rust between the rotor and hub.
Cracked brake pad.
Bad pins in the calipers.
Moons of Jupiter out of phase with current sun activity.


Please let me know what you think.

[Logan@THM]

Originally Posted by ClawSS

All car guys like a good bench discussion on what some other guy needs to do, so here's a good one.

I am looking for opinions on where to begin my interrogation of my 2010 Camaro SS braking system due to a braking issue that I have been experiencing.

Background:

2010 Camaro SS with Brembo 4-piston calipers front and rear. They consist of the OE rotors and actually with only 26k miles, the OE pads. The car is lowered about 1.25" from stock and has about 1 degree of negative camber in front and

Symptoms:

When riding at speed for a period of time (between 10-20 min.) I will get a severe shudder from the front end when I initially apply the brakes. It does not have to be a panic or aggressive use, but the shake is quite unnerving and felt in only the steering. If I immediately release and reapply, the shake is not present and I experience the expected grip that is Brembo. I can no longer recreate that situation unless I spend about the same amount of time without applying the brakes, but requiring speed, not just coasting for 15 min.

There is no ABS feel of activation (push / pulsation) in the pedal, so I am not certain that the ABS sensor is faulty.

Possibilities:

Rust between the rotor and hub.
Cracked brake pad.
Bad pins in the calipers.
Moons of Jupiter out of phase with current sun activity.


Please let me know what you think.

I have experienced this exact issue before. Pick up a new set of pads, and get the rotors checked out to be safe. Swap the pads and flush the system as precaution and you should be fine. Mine seemed to have only partial pad contact (for reasons unknown) for a brief period of time causing uneven pad wear. Shoot me a pm if you want to order a set of HAWK or EBC pads, Ill take care of you on cost!

[NotYetLegend]

What a crazy problem OP. Mine shutter at speed when I apply the brakes due to a warped rotor but that happens every time you apply the brakes of course. Yours being intermittent in the way you describe pretty much rules out a warped rotor being the issue.

As suggested new pads would be a great starting point, there is a nice take-off set of OEM pads in the classifieds right now actually if you are trying to save some bucks, http://www.camaro5.com/forums/showthread.php?t=372459.

You mentioned the pins in the caliper potentially being bad, I had thought about this previously, do these pins wear out? I have seen new ones for sale online pretty cheap so it's no biggie to replace them.

Whatever happens best of luck getting everything sorted, brake issues are no fun! Please keep us updated.

[ClawSS]

my train of thought....

I won't know precisely until I get up in there, but thinking about what Logan said and uneven wear on the pads...could that be a product of a sluggish piston in one or both of the calipers? They are on each end of the pad so if one is sticky then it would not push into the rotor as quick causing a minutely skewed pad contact. Then by the time I push again I have both pistons caught up and get a decent feel.

Maybe, hopefully, I can cautiously extend the pistons and clean them without dismantling the caliper. It could just be brake dust residue.

[intensifi]

Stuck piston is my vote.

[velocity149]

Originally Posted by ClawSS

Rust between the rotor and hub.
Cracked brake pad.
Bad pins in the calipers.
Moons of Jupiter out of phase with current sun activity.


Please let me know what you think.

It's actually not Jupiter's moons, it is Saturn's. We are in the third equestrial cycle of the annular calendar, and the gravitational enomolies cast from the geo syncronal motion of those large, moving bodies around an even bigger round body, are what is causing your brakes to shutter.

Realistically, stuck piston. Cools down when going at speed for time, and gets stuck. Hit the brakes and heat it up, and it fixes itself. Just my $0.02

[ClawSS]

Remedies for a stuck piston?

I am waiting for the weekend to tear into it, so can I clear from the outside if I extend the piston when the caliper is off of the rotor by depressing the brake? I will make sure I have a helper watching the piston and not push all the way out..or will they even push all the way if I leave the pads on? Help?!?

[intensifi]

Originally Posted by ClawSS

Remedies for a stuck piston?

I am waiting for the weekend to tear into it, so can I clear from the outside if I extend the piston when the caliper is off of the rotor by depressing the brake? I will make sure I have a helper watching the piston and not push all the way out..or will they even push all the way if I leave the pads on? Help?!?

This is tricky to do.

Note: I AM NOT AN ASE CERTIFIED MECHANIC.

WITH THE CAR OFF, NO FOOT NEAR THE BRAKE PEDAL AND THE CAR PROPERLY SUPPORTED... I'd pull the caliper and remove the pins/pads. Open the top of the brake fluid reservoir. Push the pistons all the way in. Did they all travel about the same distance? If so, good. If not, could be stuck piston. Was one of them hard to push in? If not then you probably do not have a stuck piston. Close the top of the brake fluid reservoir. Remove the rotor and re-install the caliper with just the top caliper bolt. Rotate the caliper til it's horizontal to the ground. Tighten bolt to keep it that way. (It's ok to reuse the caliper bolts in this step). Use protective goggles and gloves. Put a thick piece of wood in the caliper replicating the thickness of the rotor/pads combo that is long enough to stand one end on the ground and have the other end be in the caliper adjacent to ALL the pistons. DO NOT JUST LEAVE THE PISTONS EXPOSED. THEY CAN SHOOT OUT AND CAUSE SERIOUS INJURY AND/OR DAMAGE. Turn car ON. Engage the brakes. Turn car OFF. Did all pistons move out to engage the piece of wood? If not you have a stuck piston. If yes, open the reservoir cover again. Work the piece of wood loose. Push the pistons in. Close the reservoir cover. Reinstall everything using NEW caliper bolts.

The reason for all the effort is so you do not have to bleed the calipers. In other words, you never disconnect the brake line or open the bleed screws.

If you have a stuck piston you can try to rebuild the caliper/piston in question. This is a precision procedure. If you are not comfortable, have a certified shop do it.

Note: You'll probably want to reinstall it first as is until your new parts arrive (see below).

With the fluid, piston, dust boot and seal out, carefully inspect the cylinder visually and with your finger. If it is scored, it's new caliper time. If only the piston is scored or you can see/feel damage to the seal/boot, replace just the damaged parts. Reinstall the caliper and bleed your brake system. YOU WILL NEED FLUID FOR THE BLEED.

Side note: With the crazy low prices on Amazon for our Brembo calipers, I'll probably never rebuild a caliper again.

[ClawSS]

Wonderful reply. I will be very careful and use these instructions when I start on it tomorrow.

[intensifi]

Originally Posted by ClawSS

Wonderful reply. I will be very careful and use these instructions when I start on it tomorrow.

Go buy new caliper bolts before you start. Ours are single use torque to yield.