Solution for pressuring piston from caliper

[autobonrun]

When pistons are tight and partially frozen in calipers, it’s always been an issue for me to supply enough pressure to move them. Hose connections always leaked too much. I finally found a fitting that screws directly into the caliper’s brake line inlet. The good news is the pressure side has the same connection as a tire stem so it’s easy and leak free to apply pressure. I’ve posted a photo wi manufacturer’s information.

[djpateman]

UMM, if you are trying to use a 1/8" NPT thread in place of the correct 10mm 1.0 pitch, then you are asking for problems. For thirty years of rebuilding calipers I have used a pedal cluster with master cylinder and brake lines to pop the pistons hydraulically. So you don't really need to remove from the car.

[$yncro]

I need a solution on my frozen cylinders too.. I like the pedal approach but I'm rebuilding
All my brake system. How about adapter to the 1/8 npt like this one.
https://www.speedwaymotors.com/Earls-02112ERL-Hardline-Adapter-1-8-Inch-NPT-10mm-x-1-0-Concave,390758.html

Oops.. I guess that's backwards..
I'm sure there's a 10 mm male to 1/8 female somewhere.

[Joe Bob]

Zirc fitting and a grease gun.

[autobonrun]

Originally Posted by djpateman

UMM, if you are trying to use a 1/8" NPT thread in place of the correct 10mm 1.0 pitch, then you are asking for problems. For thirty years of rebuilding calipers I have used a pedal cluster with master cylinder and brake lines to pop the pistons hydraulically. So you don't really need to remove from the car.

I don’t think I’m a good enough mechanic to replace those o-rings in the calipers with the calipers still on the car. Doing it on the bench was challenge enough. Like you I was also concerned about the thread pitch difference, so I only threaded in until I met resistance. That was enough to be air tight without causing any damage to the thread. I like the idea of a grease gun. A non compressible liquid is always the preferred method to move a piston.

[autobonrun]

Originally Posted by Joe Bob

Zirc fitting and a grease gun.

I’ll look into this setup. I know a tool store that probably has it. I’m not familiar with a Zirc fitting. I’ll need to research it. Do you just use regular brake fluid in the grease gun? I assume you don’t want to get grease in the caliper.

[john walker's workshop]

Easy to fab up something like this.

[autobonrun]

Originally Posted by john walker's workshop

Easy to fab up something like this.

Wow. That’s a nice setup.

[Joe Bob]

A zirc fitting is a grease fitting, use a grease gun with grease in it.

Old Indian trick as my Dadz would say.

[autobonrun]

Originally Posted by Joe Bob

A zirc fitting is a grease fitting, use a grease gun with grease in it.

Old Indian trick as my Dadz would say.

Thanks.

[Joe Bob]

Put a block of wood between the pistons and pump SLOWLY.....sometimes it can be quite explosive and you don't want them whacking themselves together.

[LakeCleElum]

Originally Posted by Joe Bob

A zirc fitting is a grease fitting, use a grease gun with grease in it.

Old Indian trick as my Dadz would say.

Joe Bob is Correct. Just used it last week on 3 motorcycle calipers that had been sitting since 1992. Slick trick.

[$yncro]

Originally Posted by john walker's workshop

Easy to fab up something like this.

Excellent!! I might copy this one.
Thanks!

[Joe Bob]

John Walker/Rube Goldberg

[Carl S.]

I used a diesel injector pump from Ebay adapted to the brake lines. Mine were frozen Solid!!! pumped them full of water to free them up. I used a rubber stopper to plug up the loose one and freed the other.

Slick!!!!!
Platted and rebuilt them myself and turned out Sweet.

[autobonrun]

Originally Posted by Carl S.

I used a diesel injector pump from Ebay adapted to the brake lines. Mine were frozen Solid!!! pumped them full of water to free them up. I used a rubber stopper to plug up the loose one and freed the other.

Slick!!!!!
Platted and rebuilt them myself and turned out Sweet.

I used the piston that popped out as my stopper by pressing it in slightly then held it in that position using a c-clamp while I applied pressure to the caliper. Both my rear calipers had a frozen piston. The fronts came out easily.

I can’t imagine trying to rebuild a four or six piston caliper. Holding one in place made my day.

[Arlo911]

Use the grease gun. It's messy but a whole lot safer than using compressed air. I just removed some pistons from aluminium S calipers this way, works very well

[cmcfaul]

just use the car. Pull the caliper off the disk and step on the break. One side will pop out. Gently use the the piston to clog the hole and step on the break again and the other piston will com out. no need to overcomplicate

[autobonrun]

Originally Posted by cmcfaul

just use the car. Pull the caliper off the disk and step on the break. One side will pop out. Gently use the the piston to clog the hole and step on the break again and the other piston will com out. no need to overcomplicate

You can’t pull the caliper off the disk with the close coupled hard metal brake line still attached. It’s an exact fit and there is zero give in the line. Otherwise good solution.

[cmcfaul]

Did it a week ago. No issue at all.

Chris