Piston boot heat/rust.

[Klas]

I changed this piston boot because of the smaller cut that was visible from the side. Probably after someone put a screwdriver through the rubber trying to prize out a brake pad.
To the inside of the calliper the boot was completely worn out. My concern is if the damage is from heat or from rust tearing the boot. The piston hade some rust pores but nothing big and I managed to polish them down/away.
One theory is that water came in from the cut and gathered in the bottom and the piston started to rust. The other is that heat burned the boot and if so probably the other 3 pistons need a check. What do you think?

 

[DocL]

The first one looks like a cut, but the second two are definitely burned.

Do you track your car often? I found that after three or four track events that I needed to replace the seals.

 

[nsxtasy]

Yup - been there, done that. Heat can cause them to disintegrate. If you know how to rebuild the caliper, you can get a kit from your dealer with the various pieces you'll need.

 

[Klas]

So far I’ve only tracked my car 4 times but this season I have planed at least 10 events. Do you replace all your seals and boots after 3-4 events!? It’s a big design flaw if that’s needed and an expensive one also and strange that I have not heard of this before on this forum or in the FAQ. I paid ~50$ for one seal and boot to 40 mm piston so if we need to rebuild the front callipers after a few events a solution from Brembo should be natural.
The rust was only on the downward side outside of the seal. The seal was as new contrary to the boot.
It’s not an attack on you Dr. Lane but I cant believe that its so ordinary that boots burn. Thank you for your input.

 

[nsxtasy]

Do you replace all your seals and boots after 3-4 events!?

I don't replace mine that often - only when they need it. Probably more like every 10-15 events or so, unless I'm on a track that REALLY heats up brakes. (Some tracks are better about that than others.)

Cooling ducts to the brakes will help. I have two-inch ducts that run from the front air dam, squeeze alongside the bottom corners of the radiator, and attach to a flange that I had welded along the edge of a two-inch hole cut in the brake splash guards.

 

[gobble]

You paid $50 for one seal and boot? Or 50 Swedish Krona?

I hope you misspoke because I just ordered all 6 seals and boots. Acura of Brookfield claim they don't sell a rebuild kit, just individual parts. Didn't imagine they could cost that much. Is this accurate? Anyone know how much these should cost?

 

[nsxtasy]

Good questions.

I'm not sure but $50 or so sounds in the ballpark (reasonably close) for all the parts to do both FRONT calipers. Note - I've never had any heat-related problems with the rear brakes at all, and have never rebuilt them.

Acura of Brookfield claim they don't sell a rebuild kit, just individual parts.

I may have mis-spoke. I was referring to the parts to do the rebuild. They may indeed need to be ordered as individual parts rather than a kit, and I think this sounds right. I just tell the folks in the service department and they know what I need...

 

[Klas]

I paid 214 SEK for one boot and 204 SEK for one seal - about 54 US $.
The seal was without any damage but should be replaced according to the service manual. For all 4 pistons front 200$ is probably correct.

 

[gobble]

Anyone ever try having the rotors refinished when doing brake work? I know some rotors are best not being refinished and that many shops refinish rotors on-car these days. What works best for the NSX? Can the rotors be refinished? Does it cause problems (such as brake pulsation) if you take the rotors off and put them back on? I'm curious to know what people do with NSX rotors.

 

[Larry Bastanza]

In regard to the brake parts, there are "kits" and individual parts based on year, and/or front vs. rear. For example 1997 rears can ONLY be bought as a kit. The thing is I paid $40 US for a complete rear kit here in the US. This kit is very comprehensive, since it provides every thing to rebuild the e-brake as well as the seals.

Klas,

If you would like maybe we can work something out to help you with the parts. Let me know what you need, and I can see about helping you.

Ken,

FYI, I just did a rear caliper for Peter Mills, got pretty "cooked" at the track, the boot was toasted. Peter does do a lot of track day though!

HTH,
LarryB

 

[nsxtasy]

Anyone ever try having the rotors refinished when doing brake work?

Yes, but... If you're having problems with pulsation/shudder, turning the rotors will leave them more susceptible to additional problems. This is caused by uneven deposits of pad material, as noted here.

John Vasos (Acura of Brookfield, your local dealer) is an expert in this. Discuss with him. What they will do first in cases of shudder is try using ScotchBrite (?) pads to buff off any friction material, and only then see if they need turning.

Can the rotors be refinished?

They can, but see above.

Does it cause problems (such as brake pulsation) if you take the rotors off and put them back on?

Taking the rotors off and putting them back on doesn't change anything and doesn't cause pulsation.

I'm curious to know what people do with NSX rotors.

Mostly, I replace them.

Again, discuss with John.

 

[gobble]

I don't have any problems with pulsation but don't want to create any by doing the wrong thing. I know that in the days when I was younger and didn't try to work on my cars, the dealers would always refinish the rotors when replacing brake pads and charge me through the nose. Since then, I've always thought that to do a proper brake job you refinish the rotors.

I have a friend who is a service manager at the local Mitsubishi dealership that told me I would just create problems by taking off the rotors and having them resurfaced. I want to do the job right, but it sounds like doing it right might mean doing nothing at all.

 

[nsxtasy]

If I'm not experiencing any problems, I don't have the rotors turned when replacing the pads.

 

[Klas]

Larry: If its possible to compose some kind of kit to easy rebuild the callipers complete with seal, boots and maybe some other practical ”stuff” it would be great. In fact it was the first time anyone ordered seal or boot in Scandinavia and delivery was about 3 weeks so they probably came from Japan.
The weather strip on top of the windscreen is revised in US but in Europe they don’t know of this so sometimes it’s a bit problematic to have a rare exotic.

 

[gobble]

I just picked up some of the parts and it was $124 for 5 boots and 4 seals. I alread had one boot and the other two seals are due in tomorrow. AOB was good about discounting the parts. List price was somewhere over $200.

 

[gobble]

So whats the secret for getting the piston back in through the new boot?

 

[Klas]

So whats the secret for getting the piston back in through the new boot?

I forced one side of the boot over the piston with my fingers and then rotated around the piston with one finger between the boot and piston. Good luck.