caliper piston removal

[Steve P]

Anyone got a way of removing caliper pistons off the car,i have no way of pressurising them out and i dont want to knacker the pistons with grips.They are Wilwood four pots by the way.
Cheers
Steve

[Nick Jones]

Depends if they are stuck or not.  If not stuck you can easily blow them out with a foot pump (even a bicycle pump), just bodge up an adaptor. It helps if it has a one-way valve in it to assist with building up pressure.  The trick is to prevent them from coming all the way out until you have shifted all the pistons, and keeping a rag wrapped around it so you don't accidently launch any pistons.....

If I get stuck with a stubborn one I tend to attach them to the car and use the master cylinder to pump them off - ithat doesn't shift 'em you have a problem!

Nick

[Glenn]

I did this job earlier in the year on Transit Mk1 four pots.  IIRC 3 pistons gave up without much struggle on each side but one was seized in each caliper.  Plenty of penetrating oil, clamp up the free ones (G clamps) and use an airline to force the akward ones out.

Careful - can be quite dangerous.

[Mac]

Take the pads out then blow the pistons out onto the discs or a spanner or something. Otherwise one side will blow out and the other won't.

[Clive]

had varying success with airlines, they wont shift really difficult ones. Lots of penetrating oil over time (some took a month) and a master cylinder are the ultimate solution. Have heard of a grease gun being used, but don't see the advantage over a m/cyl.

[chrisspe]

just hook it up to the cars hydraulics and pump the beake pedal  (g clamps can be used to restrain less stubborn pistons if your luck enough not to be dealing with single piston ones)

[willcolumbine]

Chuck a peice of wood in between the cylinders and hook the bleed nipple up to a footpump. This worked for me big time!

[piman]

Hello CH,

"Have heard of a grease gun being used, but don't see the advantage over a m/cyl."

I use a grease gun, handier if the caliper is off the car and on the bench and I suspect that there is more pressure from a grease gun.

Alec

[Einar]

I have just did this: Foot pump worked very well for three of them. The forth were stucked. I hooked it to the car hydraulics: just blew out - worked very well. As said in various replies above  ;D

[Deleted User]

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