Magura HS33 brake trouble

[JLH85]

I'm looking for some info on some Magura HS33 brakes.
The piston on the drive side of the bike is really slow and moves only a fraction of the distance of the other.
I've re-bled them and holding one piston they both move really well.
Its only when trying to operate them together that there seems to be an issue.

Any help would be appreciated.
Thanks

 

[Lighty]

Have you tried cleaning around the circumference of the piston with a damp cottonbud or little contact cleaner first? Only takes a little grime to stiffen them up

 

[Lighty]

Had it on mine, took a process of gently clean.. then squeeze then repeat and repeat and repeat until it finally moved at same rate as it's oppo

 

[JLH85]

Cheers guys.
I have already tried cleaning the pistons up but didn't seem to help.
Is there anything else you would recommend?

Thanks

 

[Lighty]

did you lube the seals again after a good cleaning?

 

[Bullpup]

Use XCP spray to clean and lubricate the pistons.

 

[My_Teenage_Self]

Does it actually affect their use? it's not uncommon for one piston to move 'faster' than the other.

But, I'd second the avove of lots of cleaning & pumping of that piston.