rear brake caliper stuck?

As mentioned while introducing my 'new' Silverwing, I am waiting for the registration procedure, and meanwhile giving the Honda a once-over.
When it wanted to take a look at the rear brake pads, I hardly managed to get them out of the caliper. It seems that one of the pistons is 'stuck'. I couldn't push the caliper 'inwards' like it should and even a gentle wedging with a large screwdriver (not the wodka-orange kind) didn't move the piston.
I am thinking of removing the caliper and trying to use pliers to push the piston inward. Is this advisable, or do I have to dismantle the caliper and rebuild it? (I did check the fluid level was not too high in the master cylinder)
In case of a rebuild, are the kits offered on eBay (pistons and seals) a good choise?
All advise is welcomed.
Many thanks in anticipation.

Buy the whole caliper assembly on eBay

Probably because the previous owner did not change the brake fluid
at 2 years as recommended by Honda

Honda recommends using air pressure in the fluid inlets to remove the
pistons

Pege 16-28 in my Silverwing Service Manual

This happened to me once on the rear also. My screwdriver and even my metal spanner wrench handle that I stuck in the gap could not move the pistons (with metal I was afraid to exert lots of force for fear of damaging something). I then got a long piece of 'hardwood' that fairly well filled the gap between the pistons and then pried (by hand using the leverage of the long wood handle) and twisted (using vice grips) and (luckily) the pistons moved (albeit very slowly) back (but I was surprised how much force it took). At the end after much prying/twisting, when I had moved the pistons about as far as I could get them moved, there was just barely enough clearance to get the new pads slid over and onto the caliper disk. It all worked out fine in the end - but those pistons initially did not want to move back to make room for the new pads while giving sufficient clearance for reassembly onto the caliper disk. Good Luck with this one as I was also very initially frustrated in getting any piston movement; however, once I got some piston movement more seemed to come easily - but at the end I still could not get piston totally in (i.e., flush) all the way - but still had just enough clearance for reassembly.

Today I removed the rear caliper and behold.. I found a 'foreign object' inside! (a metal clip that is not in the manual)

After a thorough spraying with brake cleaner (I'm still 'high' on the stuff) refit everything and did a short testrun (no plates, remember) inside the garage. The feel in the left lever is OK and the rear brake is working again. (The clip kept the 'top' side of the pads open)

Adjusted the parking brake too, repaired a non-working parking brake light (bad connection under the 'glove box'), and had a peek inside the air filter box...



O.M.G. This is the second time in 40 years and +70 vehicles that I came across a filter this dirty! (But the one in my 1948 Aero Minor did have an additional feature: a mouse nest ...)

The Silverwings filter is a close second:



Ordered a new one in the UK through eBay = cheaper than in Belgium... (even with p&p!)
Long live the WWW :-)

Make sure the spring goes back on correctly, it took me a while since no one in here has ran into the problem

@tankyuong:
thank you for this notice.
It took me some time too:
the clip ('retainer' N°9) has to be pushed into place on the bracked (N°5)



On my Wing it was (slightly) distorted and 'floating' between the brake pads!

In the mean time, I've also flushed front and rear brakes, there was some air in the center front caliper, i.e. the one activated by the 'left' brake lever.

Can't ride the bike yet, since I'm still awaiting the registration... 'only in Belgium'...

rodenbach wrote:

@Silver Wing Rider:
thank you for this notice.
It took me some time too:
the clip ('retainer' N°9) has to be pushed into place on the bracked (N°5)



On my Wing it was (slightly) distorted and 'floating' between the brake pads!

In the mean time, I've also flushed front and rear brakes, there was some air in the center front caliper, i.e. the one activated by the 'left' brake lever.

Can't ride the bike yet, since I'm still awaiting the registration... 'only in Belgium'...

I was talking about #3 spring that falls out when you take apart the pads

now thats an informative post , i always use a caliper compresor tool if you dont have onw a small g clamp will come in handy to get some movement on the pistons .
If the pads are tight i use a removal tool for those too.


The clamp works to get the piston moving then you can remove the pistons to rebuild the seals etc .
Derekj

@tankyuong:

for what I have seen the #3 spring/retainer is to be 'clicked' onto the main body of the caliper. On my bike this retainer doesn't fall out when removing the brake pads. I have been fiddling with the pads and caliper a number of times before I found out how and where the #9 clip had to go, and all of the time the #3 spring stayed nicely in place.

I have cleaned the brakes using a spray can and an electric tooth brush, and even then the #3 spring didn't come off.