Help - front caliper rebuild (burned rubber seals from track day)
 

So, last year, before I stored the car for winter I tracked my 350z on stock rotors and calipers. I had track brake pads and racing brake fluid.

Yesterday, I built a brake duct system and was going to upgrade my rotors to some slotted stoptechs, but when I took off my calipers to inspect my track pads the rubber seals on the calipers were fired on the fronts.

I've never rebuilt calipers before. A rebuild kit with new rubber seals is not expensive (under $6 a piece at autozone).

I've watched some random caliper rebuild videos on youtube, but does anyone have a 350z video or howto guide for non-brembos?

I'm also concerned that this will be an ongoing issue (i.e. having to rebuild caliper seals after every track day because they get fired). Anyone have any experience with that? I'm hoping with my new brake duct system, and some slotted rotors that I may be able to extend the life by running a bit cooler. Obviously a BBK is where it's at but $3000+ isn't in the budget right now.

Thanks!

I fried my dust boots years ago and had a reaction similar to yours when I discovered it.

However, they are not "needed" for good brake operation. Their job is basically to keep the piston clean so that it doesn't damage the inner seal (that keeps brake fluid from leaking past the piston) when compressed (during a brake job).

Without the dust boots, you just need to clean the pistons before compressing them.

If you ever notice a leak of brake fluid at the caliper, then they need to be replaced/rebuilt.

If you're going to be doing more track days, the question should be not if, but WHEN will you purchase a set of Brembos? I'd suggest looking at the classifieds here and buy a set of used Brembo calipers and combine them with some brand new rotors. Should be a lot less than $3K. The smaller brakes simply won't have the heat sink capacity for driving at the track.

I know. I've been searching for the track model Brembos and they exist for sale, but I'm just not looking to spend the money right now. Usually I'm an advocate for stating that the cheapest person spends the most (in the long run), and I generally do things "right" the first time; however, $3000+ for some track day fun once a month for a few months is a bit steep. This car is not my daily driver (100% track dedicated). It will happen in time, but for now, I have brand new rotors and tracks pads (all around) for my existing stock calipers. I did build a brake duct system (literally yesterday) so I'm hoping that will reduce brake temps on the fronts.

Doesn't look like the caliper rebuild will be all that difficult. Hopefully I don't have to do it after every track event, but those calipers have on them the original seals since 2005 so it may have been a combination of old and extreme heat and no brake ducts and stock rotors (i.e. not slotted).

I have to replace the seals on my oe brembos every year, so it's not a fool proof solution. Bakes should always be inspected regardless how much money was spent on the parts

There are many guides out there, but to remove the piston to gain access to the inner seals. Take compressed air to the brake line fitting and pop the Pistons out.

Thanks for the comments Blurvision. I appreciate knowing that. I do inspect stuff regularly, and sounds like it will be a somewhat frequent repair. My friend has an air compressor in his garage so it shouldn't be that bad.

For sure! I gave up on the tiny '03 stock brakes after about 6 track events. They just ate up pads and often overheated even with racing fluid. Went with the Akebonos BBK upgrade. They cost around $2K new for a complete setup (calipers, adapter, pads, rotors, SS lines & fluid). The Brembo's are about the same size as the '06 brakes so its an improvement, but the Akebonos are monster sized. I only got two session on them before an unrelated hub problem ended my day, so can't really comment on how they hold up to track abuse just yet.

03 to 06 = 8% larger
03 to OEM Brembo = 10% larger @ $1K cost used
03 to Akebono BBK = 20% larger @ $2K cost new
(all numbers based on front rotor size)

To me the the Akebono's were the better deal. Since they are OEM parts from the Infiniti G37 and 370Z Sport models you shouldn't have problems finding pads & rotors at reasonable prices.

Depending on your skill level/pad compound/track config be ready to fry the boots again after you go through another set of pads. They tend to go when your pads get down to less than half and you get a lot more heat transfer into the caliper and pistons. Ti shims wont help much with boot degradation either, if you are using sticky tires and an aggressive pad compound.

Rather than replace the boots every time you see cracking, decide on a rebuild service interval where you will be cleaning the bores of the caliper, replacing the seals and replacing the boots. On race BBKs they dont have dust boots but obviously the service interval is more frequent. This will depend on how often you go to the track.

Makes sense. I just installed new track pads on the car (Carbotech XP10’s) so maybe the rubber seals will last a bit longer, but that’s good to know. I will plan to inspect frequently and replace every season. For a $12 repair kit it’s not worth not replacing them. Rebuilding the caliper was not difficult at all. The trickiest part was plugging the brake line but a variety sized small box of rubber vacuum caps from O’Reilly Auto Parts did the trick. Otherwise, just pull off the old seal, use an air compressor to push out the piston, take out the inner seal, clean everything, grease up the new seals and install, push in the piston, reinstall on car, and bleed the brakes.

As a follow-up. I ran 7x20 minute sessions at a track event last week with new pads (Carbotech XP10's) and new rubber seals. After the event, I checked the rubber boots on the fronts and rears. The rears where ok. The front driver side *did* get fried again. It was not as bad as last time, but it was burned and brittle in one area near the top (I rebuilt it again). The passenger side was alright. I re-greased the boot on the passenger side and left it on. I suspect they will have to be rebuilt again after I go to the track in 2 more days as my pads are like 75% worn now. I plan to run 3x20 minutes sessions on those pads and then swap (at the track) with another set of Carbotech XP10's that I have that have about 40% remaining and run the last 3-4 20 minute sessions on those.

One thing that sucked is that on this rebuild, I think I got too much air in my brake line after disconnecting the line and caliper. I plugged it the same way (using rubber vacuum caps) but after bleeding the fronts with only less than a half bottle of fluid that I had left wasn't enough to make me feel comfortable that all the air is out. Will flush and fill completely tomorrow with rbf600. I might try to just swap the boots without disconnecting the brake line from the caliper next time. With the pads so worn after track events the caliper piston is out sooo much that I probably could have just slide the boot on while leaving the brake line attached. What's more wasted money in this hobby anyway right?

.. it's amazing how quickly the budget just goes.. :suicide:

Good luck with the brakes, I had plenty of issues with mine over the years. I see you are in Lansing? You tracking at Grattan or Gingerman?

Gingerman. I'll be there tomorrow for Gridlife. You go out there often?

You will love the StopTec rotors, I just put them on a few days ago. They also make their own bbk that goes for $1200 retail. GL

Not often. I try to get out there once a year. I'm sort-of eastsider. It's about 2.5 hours from home.

As far as putting the boots on with the caliper attached - seems you should be able to do that. might get tricky if it requires some 'finessing' to push it all the way in. If the piston it already out part way.. should be able to.

What boots are you using? oem? not sure what options are out there for the oem non-brembo calipers. something aftermarket might be more durable.

Do you have a link to a StopTech BBK for $1200?

Yeah, I gotcha. It's like 1 hour and 45 minutes to get there from where I'm at, which sucks b/c tomorrow drivers have to be there at 7am for the tech inspection which means I'll be up before 5am. The rubber boots I'm using on the fronts (that I replace as needed (i.e. every 1 - 2 track events)) are just some standard ones that I can get at Autozone for like $6.99 each, which is great. The problem is that I can't find a rear caliper repair kit for the OEM calipers, and I called Nissan today and they want $56 a piece for the rear rubber seals and rubber boots. Yeah right, I declined. Need to find a cheaper option somewhere. At least the rears are not as problematic as the fronts. Hope to see another Z out there at the track someday!

When I get back to the casa I will find that link for you.
Cheerz.

Thanks!