TR6 Brake Piston Tight

[Matt1969]

Hi, just managed to replace three brake pads without too much trouble after levering the pistons back. The last one though, the piston just won't shift. It's solid. Any ideas? Posted in general chat by mistake. 

[Waldi]

If it really does not move, it is provably froozen.

Have you tried to push it in with a C-clamp (calliper removed)? Or (carefully) with a screwdriver between disc and pad (but not too much force to avoid bending the disc).

And then push it out again with hydraulic pressure (apply brake). It may free itself if it isn’t too stuck. Otherwise it probably means dismantling the calliper and then it is better to do both sides.

Waldi

[Matt1969]

Ok, thanks, do you mean both sides of one caliper? 

[BlueTR3A-5EKT]

This works for me.    Made and supplied by Girling to lever the pistons back into the caliper.

[Waldi]

8 hours ago, Matt1969 said:

Ok, thanks, do you mean both sides of one caliper? 

No, I meant both calipers. If one piston in one caliper is seized, there is a fair chance the others are in similar condition (but not seized yet). Doing both calipers at the same time also avoids differences in brake force L/R.

The revision sets are not expensive. 

Waldi

[Andy Moltu]

Take the callipers off.

Blow out the pistons using an airline. (Wrap well in cloth, to retain the piston safely and prevent brake fluid being sent spraying)

Replace seals and replace any corroded pistons. There is usually a reason they stick with corrosion being the main cause. When used regularly the corrosion would get wiped off almost immediately. But as the pads wear, the outer parts of the pistons beyond the fluid seals can corrode and you only really appreciate this as new pads are fitted and you try and push the rusty surface back in past the fluid seals.

if both pistons are shot then the cost isn’t far off a new caliper.

[wheeler]

Excellent brake information here,

https://www.buckeyetriumphs.org/brakes.

Refurbed my brakes 18 years ago using this advice, brakes still perfect today.

Hope this helps

Bill

[Matt1969]

Ok, v excited to get into a new area of mechanics for me.  Took the difficult caliper off and removed the stiff piston with a pair of heavy screwdrivers.  The pistons look immaculate, but the cylinders are slightly corroded above the seal.  Could clean off with vigorous wire wool?

[Waldi]

Yes, as long as you are careful with  the groove where the seal is. The seal requires an undamaged groove to work properly. 

Waldi