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I'd like to get some feedback about my diagnosis of a braking problem that has recently occurred - the brakes drag even when the pedal is not depressed (and no, the parking brake lever is not up ). The car is up on jack stands and I've inspected the components revealing that the drag occurs only in the right front. The pads were not binding in their mounts, but I replaced the set anyway in case they were the source of the problem. Then, while checking the brake asembly with the caliper rotated up, I noticed that about 1/4 of the piston boot is missing! I suspect that the piston seal has become contaminated and isn't allowing the piston to retract properly. I pushed the piston back in with a c-clamp and the wheel spun freely. However, after depressing the brake pedal several times, the RF brakes bind again.
1) Do you agree with my diagnosis that a caliper overhaul is the correct repair?
2) If so, any tips on doing the work?
It looks pretty straightforward, but it always helps to have tips from those that have done it before. Thanks!
I would agree with your diagnosis of the missing boot. What I usually have seen is a loss of a seal due to age, cracking, etc... I haven't dealt with straight contamination before. You might have to hone the cylinder with some sandpaper (1000 grit or finer) or scotchbrite. The surface should be glassy-smooth. Don't reuse the cylinder if you have any scratches deep enough to hang your fingernail in.
Unless you have a compressor, you'll need to blow the pistons out with the brakes. It will be messy (brake fluid everywhere) but there's no good way to remove the pistons w/o pressure. With the pads removed, pump the brakes by hand (slowly!) until the pistons come out. You might want to back both of them in all the way with a c-clamp so that you're sure they are the same distance in (so that one doesn't come out way before the other). Once you get them most of the way out, you can probably work them out by hand.
You should only need the crush washers for the line, the piston seal, and the dust boots. Not sure if Honda sells a kit for it...
A quick fix is to detach all of the boot from the caliper (leaving it on the piston), so it does not cock the piston and cause it to hang. This will work just fine until you get time and parts to rebuild the caliper.
marcucci - I have compressed air and a blower. Sounds like all I have to do is completely remove the caliper, then push the blower nozzle into the brake hose fitting and blow? The air is set to 135 psi, so I suspect that I will need to be careful about the piston flying out with some force. I'll call my local dealer for the parts.
cdelena - thanks for the suggestion on the temporary fix and if the nearby dealer doesn't have the parts I'll give it a try.
The car is drivable, but I wouldn't want to go further than a few miles.
[QUOTE]Originally posted by CoralDoc
[B]I have compressed air and a blower. Sounds like all I have to do is completely remove the caliper, then push the blower nozzle into the brake hose fitting and blow? The air is set to 135 psi, so I suspect that I will need to be careful about the piston flying out with some force.
Yes you can buy rebuild kits for the calipers . Kit comes with all seals and different greases , for seal and dust boot ( includes crush washers for the brake line). The seal of the piston , is made on the surface of the piston and the piston seal , not the inside bore of the caliper ( no need to hone caliper ) . There is a grove in the caliper that holds piston seal . It will take very little pressure to get piston to move out of caliper ( 10 to 20 lbs max) . If you don't have compressor ,just push punch through brake line hole against in side of piston and push out piston . When you remove piston examine it , the outer surface should look like a perfectly chromed part , if it has any pits or rust just replace piston . You can get just one kit if required . There might be a steel ring inside dust boot holding it in place . You just need to find the end of the old steel ring , pull it out , then remove old dust shield . rebuilding front caliper is a piece of cake . When you get to the rear , it is not as easy . The emergency brake feature adds to the complexity . You will also need special snap ring pliers to dissemble the rear calipers .
brad
ps
If you remove steel ring holding on dust boot , you can just remove complete dust sheld , it is only used to keep dirt off of the piston .This is only a problem when you push piston back in to replace pads . It does not seal fluid in any way. You can replace dust shield with out rebuilding the caliper .
FOLOWUP-
Here is one of the rebuilt calipers on my car.
They don't drag any more! I did the R & R myself and thanks to Joe (Turn Key Terror) of American Caliper in Coral Springs, FL for refurbishing them. Their shop is now the premier caliper rebuilding center for the S2000 . Beware that caliper rebuilding kits are not normally stocked by Honda part centers (none of the ones near me had them) and it will take a few days to get them in.
well if your rebuilding a caliper, most times the piston is sized from rust build up, you do need to hone it, get rid of the rust.
if your just rebuilding cause your boot is bad then by all means replace that. I'll be making a faq for a full caliper rebuild tomorrow (doing one myself)
03-15-2002, 07:23 AM
Front Brake Caliper Overhaul Questions
(and no, the parking brake lever is not up 
). The car is up on jack stands and I've inspected the components revealing that the drag occurs only in the right front. The pads were not binding in their mounts, but I replaced the set anyway in case they were the source of the problem. Then, while checking the brake asembly with the caliper rotated up, I noticed that about 1/4 of the piston boot is missing! I suspect that the piston seal has become contaminated and isn't allowing the piston to retract properly. I pushed the piston back in with a c-clamp and the wheel spun freely. However, after depressing the brake pedal several times, the RF brakes bind again.
. Beware that caliper rebuilding kits are not normally stocked by Honda part centers (none of the ones near me had them) and it will take a few days to get them in.
