Caliper releasing when handbrake is pulled on

Technical Area Wheels, Tyres & Brakes
2

Good afternoon all, 

I’ve come up against a bizzare problem when undertaking the seemingly easy job of changing the rear brake pads on my mk2.5.

Started by changing the pads, the handbrake then didn’t engage, even after fully unscrewing both rear calipers and tightening the handbrake cable fully at the handle. 

Decided that a refurbishment was required, changing the rubber seals and reengaging the screw which goes in the back of the piston, it had released itself on both sides. All this went well. 

I fully reattached the calipers, put the rear on bricks and bled the system as air had gotten into it.

Check of the brakes working, turned the engine on into first gear. The passenger disc span fine, the drivers was struggling. Applied the brake, both stopped and engine stalled. Foot brake doing its job.

Then started up again, into first, passenger spins drivers doesn’t. Applied the handbrake… Passenger disc stopped as expected, drivers frees up and spins normally. Meaning the handbrake is doing the opposite of what it’s supposed to be doing when applied. Apply foot brake, drivers stops spinning, car stalls.

Inspected both calipers, pulling handbrake pulls cable and then pulls the handbrake actuator on the calipers, as expected. 

Drivers side is an after market part and has a larger diameter of piston, passengers is standard.

I have found a dissected view of the caliper: http://i110.photobucket.com/albums/n109/saz9961/Slide1-1_zpse61b5462.jpg

Asked some of my reliable car friends, they don’t have a clue what could be causing this.

Is this worth trying to fix as it seems exceptionally bizzare? Or just bite the bullet and get two new matching calipers? It is something I caused when changing the seals on the caliper? I did not deconstruct the handbrake element of the caliper when refurbishing the brakes. I can’t comment on whether this was happening before I reburbished the calipers/changed the pads as it wasn’t something I thought could ever happen. 

Any advice, help or insight would be greatly appreciated before I go forking out for a new set of calipers. 

Thanks. 

3

You should not have two different sized caliper pistons. Someone used to the cars needs to look at this and sort it as there is something not correct here.

The car should not be supported on bricks.

You need to scew in the allen bolts to get the calipers tomove the pistons in after a brake pad change.

Again you need some help here and that needs to be someone there to advise and not remote suggestions from a forum.