unseizing sticky brakes

on my BMW, which has been sitting unused for over a year, it's very
hard to push around - I expect the brakes have gone manky, among other
things. Normally, to sort this sort of thing out, I'd just ride the
thing, but since the clutch is fubarred, I can't.

Any suggestions as to how to free things up?

Also, are the wheel axles (or spindles, or whatever) likely to have
gone bad, or the shaft drive?

Yours, clueless.

 

The wheel bearings may have. They's certainly rusted up on the SZR when
I disassembled it.

 

Most likely brakes, IWHT. Tyres definitely pumped up?

If it has CI discs then these will form surface rust which will have
more friction - it could possibly effectively thicken the disc if it's
bad. Tricky to clear without riding it. I have hand emery'd discs
before now but I don't like doing it.

If the pads are sticking then they can be freed by removing the
caliper and the pads, then pumping the pistons out slightly and
"flossing" the pistons with a bit of rag wetted with old brake fluid.

Then lever the pistons back, and repeat a few times. This usually
works for me. It's horrendously messy, though and everything needs to
be cleaned up before refitting the pads and reassembling.

 

Unbolt the calipers, one at a time. Pump the brake lever and force out
the piston. Clean all round it with a toothbrush. Apply a thin smear of
copper grease round the base of the piston. Push back (you may need a
G-clamp for this). Repeat two or three times until pushing back becomes
easy.

Incidentally, you can push pistons out a surprising distance before they
pop out entirely, because the seal is at the base of the piston.

Spindles can corrode in place, yes. Remove and grease. Top tip - find a
metal bar roughly the same diameter as the spindle, or smaller, and use
it to drift out the spindle. Leave the temporary bar in place when you
grease the spindle, and then reverse the procedure. Saves having to
physically remove the wheel (or re-align it, but you don't get that
problem on a shafty anyway).

 

BMWs have sealed-lube wheel bearings. Or my ShiteOldBoxer did, anyway.
Until the grease seal failed and it pumped out all the grease, and the
bearing ran hot (very hot), and the inner race welded itself to the
spindle while the rest of the bearing was evenly distributed in
fragments in the hub.

Having a rear wheel bearing collapse feels exactly like a blow-out. The
bike veers all over the place. In my case, it happened right in the very
centre of the Dartford Bridge, at 50mph, which was scary in the extreme.

I rode the thing 10 miles to a friend's house, at 20mph, with the wheel
wobbling like feck and *horrible* noises coming from the back end. Bob
Porecha picked it up and sorted it out for little over a ton, IIRC. The
spindle had to be cut out with an angle grinder, as the inner wasn't
going to unweld itself. Then it was a matter of a new set of rear wheel
bearings and a new spindle. Amazingly, the hub itself wasn't damaged.

 

Put it on the mainstand, get down beside the front wheel, grasp the wheel in
both hands and push your knee against the caliper as hard as you can. This
should back off the piston a little. Do the other side similarly, and then
see if the wheel turns freely. You'll probably have to do something of the
sort anyway, if you're going to take the calipers off.

Are you sure it's not in gear, and the fucked clutch is dragging?

 

err, no

<fx: shuffles off to garage>

 

Hide/plastic/rubber mallet and gently belt the caliper.

 

BMW - these are Brembo callipers? Pop the plastic cap off and use a
lever, an old screwdriver should do, to push the pads (and pistons) back
into the calliper. Then pump them out, if necessary repeat.

There is the risk of damaging the seals if the pistons are corroded but
if that's the case they're fucked anyway. I've never had a problem in
the past.

Seized wheel bearings and spindles are unlikely. Not being out of gear
is 'probable'.