[Jones Creek]

Though my right hand caliper works fine, the left caliper has seized. Is this unit serviceable, or must I replace the whole thing?

 

[bandit]

Though my right hand caliper works fine, the left caliper has seized. Is this unit serviceable, or must I replace the whole thing?

hiya,and welcome to the forum.

normally they can be serviced.soak the entire caliper in diesel overnight,then try again by connecting back up to getting those pistons out.

or you might need to,as i had to,use an air compressor to blow them out[with care].

 

[Condo]

Blank

 

[50gary]

To safely "pump" out the stuck piston use a grease gun. The piston will come out slowly not release all at once as with air pressure.

Cheers, 50gary

 

[Shep]

Also warm the calliper with a Hair-dryer to help it un-sieze.Problem with pistons that are stuck they can form corrosion rings inside the cylinder rendering the calliper useless.If the inners are fine new pistons are available

HTH

 

[Old Okie]

For a single piston caliper I wrap the whole thing in a big towel and use air pressure through the bleed port to pop the piston out. The towel keeps parts from flying to who knows where. For a 2 piston caliper, I blow one out and then put it back in and hold it with a C clamp and then blow the other piston out. The towel should protect you from flying parts if done right.

 

[Jones Creek]

When I disconnect the hose and remove the twin caliper that's stuck, and I still want to ride meantime while I look for parts, how can I block off the loose hose?

Also, where can I look for new pistons?

 

[DavidfromWisconsin]

Kero & diesel will work if that's all you have. I use PB Blaster because it's made to dissolve corrosion, remove the outer dust boot, fittings and lines to allow for good penetration. Drain the existing brake fluid and squirt some PB right in the bleed nipple and where the line comes in. My piston popped right out with the available pressure from the MC. Do a bleed and keep the MC topped off during the process. The whole process is a bit messy, but no matter coz you're going to have to do a full cleanup on re-install. Using air pressure is a bit risky. Too many things can go wrong.



From a previous post: Seized Caliper Post



Although my ride is an '80 with the single piston I was faced with a similar situation. There was so much white corrosion inside the dust boot I probably should have not bothered, but I did anyway. First I pulled the incoming line and loaded the chamber with PB Blaster as well as PB'd the front side of the piston. Then I microwaved a damp towel until it was to hot to handle, wrapped the hot towel around the caliper, repeated this a dozen times over the course of the day, bleed the system and pumped out the piston. It's pitted and most likely shot, but it did come out.

There isn't a dust boot on the dual piston calipers of the GL. I only say this to keep from confusing a new person.



Also, when you pop the pistons using air pressure, if you use two or three paint stir stick where the pads had been you will keep one piston from popping totally out before the other one. Then just remove one paint stir stick at a time until they both come out.



Do not use pliers of any kind to try and "pull" the pistons out. All you will do is ruin the pistons.