s2000 rear brake bias?

[cmerrick]

I've been having an issue this year with wearing out the rear brake pads before the fronts.
I've had the car for three years and in the past the front pads seemed to wear out a bit faster than the rears. So something is going on.

I was at Calabogie last night for one of their night sessions and also noticed the the rear rotors were way hotter than the front rotars after 20 min or so of track time. (I used one of those infrared temperature gauges to get the temp. The fronts would be 180-190 degrees celsius while the rears would be 250-260 degrees celsius)

I also noticed the driver side rear rotar was hotter than the passenger side and was actually smoking a bit after my first session. Its temp was approx. 50 degrees celsius more than the passenger side.

I am braking harder on the track this year than in past years but still I would have thought the bias would not have changed.

Any ideas?

[wing]

Stuck/ seized caliper? I go through 3 sets of fronts for a set of rear pads something is wrong for sure.

[manotickmike]

Winter driven? I'd go with stuck. The rear and esp. passenger side caliper(s) get the worst of it.
Are S2K rear rotors vented, or solid? Just curious... Lotsa manufacturers go with a non-vented rear rotor to please the bean counters. Fine for the street, a potential "fade to the point of uselessness" on the track.

[cmerrick]

I don't drive it in the winter but the stuck caliper might be it. I noticed when I come to a stop and release the brake pedal sometimes the car doesn't roll free which seems to indicate the brakes are still grabbing a bit.

Is there an easy procedure for freeing it up or is it best left to a mechanic?

btw, in answer to the last post, the front rotors are vented and the rears are just solid.

[Chris_A]

Chris, start with disassembly and inspect/lube the slides for the caliper. It may be something really simple like that.

[wing]

I had major uneven wear forever on my fronts I lubricated the sliders like a Mofo and and the issue went away. I put so much grease I had a hard time to push the pins in, this makes sure the calipers release.

[cmerrick]

I'll give that a try and see what happens. Thanks guys.

[catana]

Hey Chris,

Good seeing you last night at the track.

Also note that if you need to depress the rear piston it should be rotated while being depressed. I have the tool if you need it.

[cmerrick]

Yeah that was fun, I think I'll try a to get out to those evening sessions more often.

I have one of those piston retractor tools, but thanks for the offer.

[davet82]

What event did you guys go to?

[wing]

Calabogie lapping evenings now $150

[morrow]

Chris, start with disassembly and inspect/lube the slides for the caliper. It may be something really simple like that.

Root Moose, check your PMs. Your advice is requested!

Jeannie

[cmerrick]

What type of grease should I use for the caliper slide pins?

I have grease left over from the replacement brake pads I put on. It looks like it is silicone based. But I also have a synthetic brake grease I bought at Cdn tire. It says its okay for caliper pins.

[wing]

That's what I use.

[cmerrick]

which one? the Canadian tire stuff?

[wing]

the synthetic stuff.

[cmerrick]

I don't know if anyone is still following this thread but I lubed the caliper slide pins for all they were worth but no dice.

I haven't been to the track lately but based on the temperature gauge the rear brakes are still hotter than the fronts and the rear caliper doesn't always release all the way after I release the brake.

I'm wondering if it could be either a warped rotor or a problem with the piston not retracting all the way?

When I turn the wheel the pads do rub the rotor and they do so in one spot on the rotor more but it is only slight and I did feel a slight vibration in the pedal at the end of the last track day.

Anyone have any ideas?

Anyone have any experience with a piston that didn't retract all the way?

[schmoo]

Don't know S2K, but if the piston is stuck, it's probably time to find a new caliper.

[Chris_A]

What Naresh said. On the plus time this would be a good opportunity to try your hand at rebuilding if you were so interested.

[catana]

It sounds like the square seal inside the caliper is done and due to the high temps generated warped your rear discs. They aren't really meant to sustain temps like that. I would try to rebuild the caliper first. Much cheaper then replacing it. The kit is around $20. I have 2 kits if you're in a bind and don't want to wait on shipping. I highly doubt any dealership would have them in stock.

[cmerrick]

When you say "square seal" in the back of the caliper, what do you mean?
I take it that isn't the boot/seal around where the piston sticks out of the caliper?

I might take you up on your offer of the rebuild kits though. I called Honda and they are on backorder.

[catana]

There is the boot which is where the piston comes out of, then further into the caliper there is a large o-ring type seal that has square edges. This is the actual seal that keeps the brake fluid in the chamber and retracts the piston. Let me know if you want the kit. Also i have the manual which has a good exploded view of the rear caliper.

[mightymousetech]

When you were lubing the slider pins, did you check to see if the rear pads were free to slide back and forth in the brackets? When servicing the brakes (which should be done every second oil change) this is the most important step. We pull the pads out and clearance them with a sanding disk to make sure they are allowed to back off from the rotor when you release the pedal.

[cmerrick]

When you say "clearance them" what do you mean?

Do you just sand off the surface of the pad? or is it something else?

now that you mention it I didn't check to see if the pad would slide back and forth in the bracket.

[mightymousetech]

Sorry, did not see this question till now.

When we "clearance" the pads we are taking the pads out and grind off material at the end of the ears of the pads (ie top and bottom if you are looking at them sitting in the brackets) They should be loose enough in the brackets that they are completely free to slide sideways, but not so loose that when you try and push them up and down they have much movement, there is a very fine line between too tight/just right/too loose. Too loose and they will make a clunk every time you change directions and step on the brakes, and will rattle over bumps. Too tight, and the brakes will feel like a seized caliper. If you can not pull the pads out easily by hand, then you found the mose likely cause of your problem. I use a 90 deg die grinder with a roloc sanding disk on it to do this.

And the rear pads tend to seize about twice as fast as the fronts, as they don't always get hot enough to keep them completely dry, so the brackets and the pads tend to rust faster.

I usually do this along with lubing the slider pins, adding moly paste to the backs of the pads and the ears etc etc every oil change, which is every 5k on all my cars.