seized calliper

[mudslinger]

i have a seized calliper piston on the rear of the mu, i have so far sprayed lotsa crc under the dust seal and i am pushing it wit a 6 inch g clamp, however the piston does not wana move. anyone got any tips or lil secrets how to get it to push back in and unseize it?
chhers

[geeves]

First question There are 2 types of rear caliper. The early one is also the has the handbrake in the caliper. The newer ones use a small drum inside the disc as the handbrake. The new ones should be quite normal and not very different to front calipers unless they have extras for abs.
The early type however can be a slight pain. Do Not force the piston back with a G clamp It will break the mechanism inside. There is a 12mm bolt on the back of the caliper that is a plug over a 8mm allen screw. This winds back the piston.Do not force it as the mechanism isnt very strong.
If all this fails BNT sell a seal kit that does both sides. They can also arrange for your piston to be resleaved in stainless steel if it has rusted.
Good luck

[mudslinger]

yep got it sorted found out bout the allan key, so got it all wound back in, never come across that before, guess they called mysterious utilitites for a reason

[geeves]

That style of calliper is used on the Mu bighorn and rodeo. A smaller version of the same thing is also used on some Mitsubishis. You are lucky you didnt damage the caliper with the g clamp.
A point of note with these calipers is that its quite common for them to leak round the allen key while adjusting Once the plug is back in though this is not a problem as the plug has a copper washer as a seal

[Demonic]

I have been doing some brakework lately, i have the leak on the R/R calliper. thinking bout getting the seal kit and doing both backs. easy job ah?.. seems simple enough.

[geeves]

They are not simple You should be able to unwind the allen key and force the piston out but personaly I would take them to a specialist and pay about 100 each. Ive used center city auto in porirua and know many others that have all good results
If the leak is at the allen key and only with the plug out this is sort of normal and not an issue

[Demonic]

yeah. Im gonna take them to ABC, i have enough work to do on my own. I was told the brass cover is threaded, so the machanic didnt want to remove it to adjust incase the cover would not go back on.

[geeves]

brass cover is just a threaded bolt. If this scared your mechanic I would replace mechanic

[Demonic]

Hm.. it looked a lil different when i toot it out. kinda like a hollow bolt.. sound right?
There is fluid leakin from the allen key. but that bolt stops it going any further.

the reason he was scared was cos it was an afterwork job and all parts shops were closed. and if it was striped and couldnt get it back in then i have no vehicle for the weekend... he is actaully a good machanic.

[geeves]

Before I had my calipers rebuilt removing this plug would result in a steady drip of fluid. It didnt even raise a mention from a Wof man who decided to adjust the brakes before issuing a wof.I havent put a finger on the rear calipers in the 2 years since