Front caliper issue

[bobbo]

Installing new flex lines for the front calipers on my SV. Had the calipers off to clean and check over. All seems good except the right caliper wont relax enough to allow free rotation of the wheel. No fluid in the system now so no hydraulic pressure. Very hard to get the pistons back far enough to clear the rotor.
Looking for suggestion before I dismantle.
Left side caliper is fine.
Bob

 

[DanR]

Open the bleeder valve and put pressure on the piston

 

[bobbo]

Bleeder , is open and the bleed passage is clear.
I'm taking it off again on Friday and will try again with the c-clamp. It seemed to want to push back when I was using the c-clamp before, like it was under pressure.

 

[sunalp]

How old are the calipers? With age and moisture (in the fluid as it is hydroscopic) the pistons get pitted
and fluid becomes slimy gunk that fowl up the seal. To move the piston back into the caliper, you can use
either a pry bar or large screwdriver to pressure the piston back in. If you're careful you won't damage the pad.
Just make sure it doesn't damage the rotor. If that fails, bring them down with you and you can leave with a new pair!

 

[Bill Blue]

I have found that if the piston won't push back, there's no point in forcing it, as you will likely end up with a draggy caliper.
Bill

 

[hartmandm]

I have found that if the piston won't push back, there's no point in forcing it, as you will likely end up with a draggy caliper.
Bill

I am curious what would be the recommendation in this situation? Push the piston fully out the other direction and then address what is preventing it from retracting?

Thanks,
Mike

 

[Bill Blue]

Yes. Whatever is preventing the piston from retracting will prevent it from retracting when everything is buttoned up and on the road.
Bill

 

[bobbo]

Pulled the caliper off again today. Pistons were a little easier to depress with the c-clamp. Re-installed and I can now rotate the wheel by hand, but still snug. I've ordered new flex lines for the front as I felt the old ones were hard to push fluid through, so probably swelling. This will allow me time to remove the pistons and clean them and the bores while I wait for the flex lines to be delivered mid March.
Happy motoring
Bob

 

[bobbo]

Removed the pistons today. Tried to pry out with a couple of flat screw drivers, but they would not budge. Padded the space between the two pistons and put the air nozzle to the fluid fitting opening. That popped them out for a good clean up with some 1500 wet/dry paper and brake cleaner, mostly some rust from sitting and lack of attention.. Re-assembled now they seem to be fine.
Thanks for all your comments and help. Purging the entire system when the flex lines show up.
Bob