Front Caliper retract

[johnradrr]

I am trying to replace the front break pads on my 1970 +2S but am having an impossible time pushing the caliper back in. I have taken the cap off the reservoir and tried a big screwdriver but no movement. I'm trying to do it without removing the caliper, is it possible or not? And does the caliper on the front screw in? Any recommendations?

[SimonH]

Probably a bit stuck but I’d crack off the bleed nipple and see if that helps.

[Ray419G]

If the caliper is in good condition It should be possible to push the pistons back without removing the caliper, (the pistons don't screw back in). I use a length of steel strip around 30mm x 6mm, gripped with a pair of large “Mole” grips at 90 degrees to the strip, this allows the piston to be pushed back more evenly than can be done with a screwdriver. Though in theory it shouldn't make any real difference, I have also found that it sometimes helps to open the bleed nipple slightly on to let the fluid being displaced escape directly, rather than pushing it back into the reservoir via the master cylinder.
Having said all that, if the piston is properly seized then the caliper will need to come off since it will have to be stripped to inspect for internal corrosion etc, or the changed for a reconditioned or better used example.

Ray

[TonyA]

Brake caliper piston retracting tool

Try spraying with penetrating fluid and using a retracting tool..widely available, not expensive ..see photo..Tony

[Baggy2]

IMHO if the piston is that tight the caliper is not going to work correctly even if you do manage to get your new pads in . As a minimum you should work the piston in and out several times until it moves in easily and smoothly but better to have it apart and see what the problem is.
Just my two penneth

[Sadbrewer]

Under normal circumstances they should come out via the methods suggested above, but they can be absolutely fossilised...we sometimes had to resort to welding a piece of flat bar across the piston , the combination of extra leverage and heat from the welding always did the trick...new pistons required of course.