Rebuilding R33 calipers

[adz]

Gday all I am rebuilding some R33 calipers that I have had sitting around for ages and am having trouble getting the pistons out.
I figure the seals have dried out stuck to the pistons so does any body have any Idea how to remove these?
I don,t want to spray them with Wd 40 etc if it will have an adverse effect later so any help would be appreciated.

Thanks Adam

[pandaah]

on the sumitomo (standard nissan GTS-t calipers) they have a ridge on the end of the piston, i used a couple heavy duty pry bars and lent against the caliper to get them out.. lubricate them with whatever you want trust me it doesnt matter... but they will come out it make take some muscles but theyll come

when the pistons are out replace the inner seal for EACH piston.. linish the piston on a wire wheel and clean everything really well with brake cleaner (its the best cos itll evaporate or wipe off without leaving a residue, and itll get rid of the wd40 or crc you used to unstick the pistons...

once youve got everything cleaned and dry, new seals and your ready to go, lubricate the pistons and seals with rubber grease.. make sure its rubber grease cos some normal greeses are made with petrolium which will eventually eat away at some rubbers.. then put the outer seal on, and the wire clip to hold the outer seal on and away you go!

have fun!

[allencr]

I figure the seals have dried out stuck to the pistons

Brake fluid attracts moisture and terribly corrodes anything that has been exposed to air except for stainless. You'll need air- 160psi or hydraulics- 1000psi or maybe a grease gun-2500psi to move it if it's really bad. Compressed air will turn the piston into a rocket, watch your fingers, head & other stuff.

Unless you're working with old Dunlop/Girling/Lockheed British stuff, I don't think anyone has made any brake parts out of natural rubber in Many years and you Should assembly lube it with petroleum based grease.

[andrew_mx83]

just use a normal compressor and stick the nozzle into the brake line fitting. do it with the caliper still assembled and stick a block of wood in the middle so the pistons cant fully pop out.

u wanna break the seal with the compressed air enough to get them most of the way out, without being completely free otherwise the caliper wont hold air pressue to get the other 3 pistons loose and u have to try and block air holes, hold the caliper and the air nozzle all at once (i did this, not fun).

[Viper]

Removed the dust boots, then carefuly use two flat head screw drivers to pry/lever the pistons out. Works a treat.
Compressed air also works, but only until you have 1 piston removed
So maybe use that to 'move' all 4 pistons, then goto the screw-driver method.

WD40'ing the lot may also help, but you should be replacing ALL the seals anyway.
And AFAIK WD40 doesnt really weaken or effect metal

Easy job, good luck.

[adz]

Thanks all for great info. I have a full rebuild kit so will replace everything.
I used the compressed air trick when I first started playing with them a while back but never thought to put a block of wood in the middle.
Will give it all a go on sat arvo and post up the result.

Thanks again. Adam

[thechuckster]

when re-assembling - DONT use lubricants like WD40 or Innox - they will make brake seals/boots swell. Maybe the 0-rings are safe, but boots (and the buckets found in the M/C) will swell and fail if you use WD or similar.

[parrot]

I am having a hell of a time trying to locate some lithium soap grease for the pistons at the moment. Repco etc don't have any, and the only old style brake and clutch place within 50kms only gets it in in bulk tins. Rubber grease was no problem however.

[takai]

Use the PBR grease in the black tube.
This stuff:

[RA35GT]

I use the PBR rubber grease as per takais post and have never had any issues. Its good stuff.

[pandaah]

so its the castrol rubber grease... do NOT use petroleum based lubricants... and using wd40 is fine to unstick them if your doing a full rebuild...

seriously its easy as ive done...... um shit ive lost count haha.. if you get stuck let me know im in perth too

[adz]

Yeah i picked up some pbr rubber grease from repco so all ready to go its what the guy at brakes west recommended I use.
Got a part number too if any body needs it. This is for a full rebuild kit for one caliper.
MCX Brake parts Part number: KX2571S
I ordered these from brakes west but you can get em on E-bay same kit I think.

[RA35GT]

How much was the kit adz?

i need to do mine sometime soon.

[adz]

Cost me $121 for 2 and they had to come from over east so I had to pay some freight.
That was full price not trade too.
I called Nissan and they wanted $186 for one kit! I thought the guy was trying to sell me a caliper. I guess thats the price of genuine parts but seemed extreme to me.

[pandaah]

thats pritty average for genuine prices... there so powerful when there freshly rebuilt tho =D