What is a caliper overhaul?

[cowie165]

I've heard it is a wise move, particularly on a 15yr old vehicle. I've looked through the service manual, and all I can see is remove the caliper and check for corrosion, remove and inspect the pistons, change piston seals, grease and reassemble.

Have I missed something or is this it? When guys say that had the caliper overhauled and found out that only 2 of 8 pistons were moving, how do you fix it? Lube??

Finally, is it a job for the home mechanic? I remember reading that the DIY overhaul kit was super exy (from Nissan). I'm happy to have a go provided specialised tools are not required.

Any info appreciated, search came up pretty dry.

Thanks

Mark

[Targa Tom]

Excessive heat will cause O-rings to bind on pistons. Not changing fluid causes corrosion.

Seal Kits are expensive... but not as expensive as Liberace'ing someone!

Check WRX Calliper kits if they fit (R32 - MY02) have similar sumitomo callipers.

If you are technical, and thorough.. DIY is OK. Need Compressor and some "Brake-Clean" to...

Hope this helps.

TT

[Roy]

GTST calipers, and most likley non Brembo GTR calipers use the same seal kit as OZ deleivered Z32 300ZX and S14 200SX so seal kit is less then $100.

One thing , i have been looking at 2nd hand sets of calipers, and also new, and it appears various calipers can have 3-4 times the flex once they get a few years on them, especially monobloc calipers. (4thou of flex later measured to be 22thou:()

So perhaps consider how much heat cycles have been thru the calipers (street/track??), how many kms as well. I doubt it will couint for squat unless you are chasing the nth degree of performance from your caliper, but im curious to know if calipers do have a finite life????

[blind_elk]

I've heard it is a wise move, particularly on a 15yr old vehicle. I've looked through the service manual, and all I can see is remove the caliper and check for corrosion, remove and inspect the pistons, change piston seals, grease and reassemble.

Have I missed something or is this it?

That's basically it.

When guys say that had the caliper overhauled and found out that only 2 of 8 pistons were moving, how do you fix it? Lube??

The overhaul basically fixes it. What happened in that instance was that brake dust got in under the dust seal, and ended up setting like concrete, totally immobilising the piston.

Finally, is it a job for the home mechanic? I remember reading that the DIY overhaul kit was super exy (from Nissan). I'm happy to have a go provided specialised tools are not required.

Can be done, but might require a bench vice to help hold the calipers while you remove the pistons (when I saw it done, the guy used 2 enormous screwdrivers to lever the pistons out, but just on the bench), and a can of BrakeKleeen or similar. Maybe some very fine (1200) paper to smooth out any little nicks in the pistons. If you are careful, you can re-use the O-rings and seals. Otherwise sus out the brake specialists for a kit.

Any info appreciated, search came up pretty dry.

Thanks

Mark

[lwells]

Does anyone have more specific pricing for R32 GT-R seal kits? Roy: is that $100 per caliper or does the set do all four?

Lucien.

[Roy]

A seal kit for my R32 GTST front calipers was something like $91 from Nissan thru Race Brakes in Nth Melbourne. (thats both front calipers)

The R32 GTST Sumitomo (spelling??) calipers use the same piston diam as the Sumitomo R32 GTR caliper, so i would be surprised if the R32 GTST seal kit cant be used as well. Ring around your local Nissan dealers to see how much for the Z32 300ZX seal kit and S14 200SX seal kit.

Worst case just courier them to Race Brakes and for $120 all up they will order the seal kit form Nissan (perhaps the get a good trade price) and throw the seal kits in for you. its about 30mins labour for them. I think it cost me $120 for the seal kit and install and about $90 for HPC coating of the calipers.

[lwells]

Urgh... $200+ for tiny bits of rubber: where does it end with these cars?!

Are there any decent quality aftermarket sets?

LW.

[Roy]

You can get the seal kit and DIY for less then $100 for fonts.

The paint was a bit ordinary on my calipers so i paid the bit extra to have them HPC coated, inlcuding the caliper pitons to try and reduce brake fluid temps. Who knows of it really makes any difference, but the theory seems to be sound:)

So you dont have to have them HPC coated or painted, but i figured if its good enough for Harrop, HSV and FPV then it cant hurt my little calipers, even if it just makes them look neat:)

[lwells]

Roy: I meant $200+ to do all four corners.

I have to change the brake fluid on my car shortly (pedal is mushier than I would like), and thought while I was at it I would change the brake/clutch lines to the braided ones I bought. Then I thought, well, why don't I add a set of SpeedBleeders while I am it? Then it occured to me that perhaps I should also overhaul the master cylinder too. And finally I thought, well, what's good for the master cylinder is probably good for the calipers....

As you can see, things are kind of spiralling out of control. And now your implanting the idea of painting/coating my calipers. Gawd damn.

LW.

[dangerous_daveo]

But can you ever stop fast enough? Hell if we were talking about going forwards doesnt matter as much, but we are talking about whats potentally the last safty device before the car crashing.

Just spend the money and fix it!

[lwells]

I agree in gerenal, however AFAIK there is nothing wrong with my calipers at all: it would just be a preventative thing.

LW

[SteveL]

I've just done all 4 calipers on my R32 GTR - new seals and boots. You can get the kits to do front and rear for around $100 through ABS. I posted the kit PN's in another thread sometime back, but will do so again here if needed.

The important thing is to ensure the piston bores are clean and there's no corrosion on the pistons themselves. As someone else suggested use fine emery to clean up the outside of the piston (DON'T use emery on the piston bores). Above all make sure everything is absolutely clean.

I use compressed air to get the pistons out.

[cowie165]

Targa Tom, Roy, blink_elk: thanks very much for the info, I'll give it a go myself. Have compressed air, will travel.

SteveL: I searched a while for anything related, but couldn't find the thread where I last read about it - probably the one you're talking about. Could you pls post the PN's and the ABS site/contact details? I'm guessing they're not "Applied Business Solutions" (abs.com.au)

Thanks again guys

Mark

[Gary2]

Hopefully another couple of handy tips.

Check under the seals to see if you have any buildup underneath them and make sure you clean them out. I used a piece of wire flattened at one end and bent at 90 deg to slowly scrape them out, you can use a Dremmel with a wire brush end if you are carefull.

When using compressed air to blow the pistons out which is a great way to do it, leave the pads in the calipers to stop the pistons flying out and gradually use something thinner as you go along. Last time I did this was on a bike and the piston came out with a bang and went flying across my w/shop.

Scared the shite out of me.

It's not a big job but make sure everything is clean, really clean before you reassemble everything and the hardess part is bleeding the buggers afterwards.

Gary

[scott]

For around $90 by a brake bleeder that run of your compressor air line one of the best tools iv'e ever bought,it all that much easier.

Cheers

Scott.

[lwells]

scott: is it a pressure bleeder, or a vacuum bleeder?

LW.

[SteveL]

SteveL: I searched a while for anything related, but couldn't find the thread where I last read about it - probably the one you're talking about. Could you pls post the PN's and the ABS site/contact details? I'm guessing they're not "Applied Business Solutions" (abs.com.au)

ABS = Auto Brake Service, check Yellow Pages for a local franchise.

PN's for the caliper kits are:

Front - SJ6070

Rear - SJ6024

1 kit does an axle set = 2 calipers. I paid $100 total for both kits.

These kits are to suit R32 GTR calipers which are the same as Z32 as well as R32 GTSt and R33, I believe (I can double check in FAST if needed).

Oh and definately take care when using compressed air - only a low setting is needed.

[xRHETTx]

Targa Tom, Roy, blink_elk: thanks very much for the info, I'll give it a go myself. Have compressed air, will travel.

SteveL: I searched a while for anything related, but couldn't find the thread where I last read about it - probably the one you're talking about. Could you pls post the PN's and the ABS site/contact details? I'm guessing they're not "Applied Business Solutions" (abs.com.au)

Thanks again guys

Mark

www.autobrakeservice.com.au

[cowie165]

Thanks Steve!

[lwells]

SteveL: Cheers for the part numbers. I will give ABS a call today. Might also see if they have an seal kit for the master cylinder (you wouldn't happen to know would you?)

Roy: How much did the HPC cost for the calipers?

LW.