new old Vision

[Lucky]

time for a caliper overhaul or a new line..

[RedRocket]

time for a caliper overhaul or a new line..

I took the caliper off.   The piston is pretty stuck now.  It's soaking in PB Blaster.

What problem could the line be?

[QBS]

Old line is rubber and soft, but not the cause of the caliper sticking.  Rebuild the caliper and replace OEM line with Stainless Steel line.  Return on expenditure is very high.

[RedRocket]

Even with compressed air through the brake line hole I could barely move the piston ???

[QBS]

I haven't done it, but some on the Forum have used a grease gun connected to the bleader valve to fill the caliper with grease and force the piston out.  You might try an Archival search.

[Brian Moffet]

I haven't done it, but some on the Forum have used a grease gun connected to the bleader valve to fill the caliper with grease and force the piston out.

This is how I removed mine.  It was not frozen though.  Compressed air is just that, compressed.  Because the friction of the moving piston is less than the stuck one, once the piston starts moving it will move really fast as the air uncompresses.   In other words, if you're not careful the stuck piston will become a high-speed projectile.

This is why I used a grease gun.  It was easier for me to just clean up the grease with brake cleaning fluid.

Brian

[inanecathode]

Its not the caliper, or the line, its the bleed hole in the master cylinder getting plugged up. I had the same exact problem with mine. You use the brakes a little, and the fluid heats up a bit and expands. Normally the tiny bit of extra expanded fluid goes up into the master cylinder through the bleed hole (if you look in there its the smaller of the two holes, almost cant see it). Instead, it applies the brake a bit. The brake drags, heats the fluid up, applies the brake harder, problem compounds.
A dragging brake can be a caliper seal sliding on the piston, or the piston getting stuck, or even a slight blockage in the line (internal lining failing and collapsing inward acting like a one way valve) but not a lever that gets harder and harder and harder.
My suggestion is rebuild the caliper and replace the line (that crap has to come from somewhere) but also get a rebuild kit for the master cylinder, and clean that puppy out real good. It doesnt take much to block the relief hole in the MC, just the tiniest bit of grit or rubber can screw the whole thing up.

[Tiger]

My suggestion is rebuild the caliper and replace the line (that crap has to come from somewhere) but also get a rebuild kit for the master cylinder, and clean that puppy out real good. It doesn't take much to block the relief hole in the MC, just the tiniest bit of grit or rubber can screw the whole thing up.

:) I have to agree with inane on this one...especially as this is a safety issue!!!!

          8).......TIGER........ 8)

[lexx790]

How do brake lines or master cylinders have anything to do with a removed caliper stuck piston???
The piston sticks because the aluminium caliper corrodes under the seals and pushes the seals onto the piston.
I use the master cylinder to pump the piston out, a lot safer than compressed air.
Scrape the corrosion out of the grooves before putting seals back in.
I managed to get my calipers alochromed  and then painted over them with high temp. paint ( not in the bores).

[fiat-doctor]

You guys are ALL right....   the old rubber hose is CRAP.  Look in the owners manual.... it says replace every FOUR years.
Replace it with stainless steel. 
The caliper DOES corrode behind the seal making the piston stick.
Clean and replace seals.
The tiny bypass port on the mastercylinder plugs and does EXACTLY as Inane says.
Rebuild the MC.

Do I have to say "it's the brakes stupid!"  Not the place to cheap out.

Not yelling at anyone in particular, just amazed that people half-repair a 25 year old bike and then ride 70mph on it.

Sirrus Consolidated has the MC kits.
Someone just posted an online source for low priced stainless brake lines.
RZ 350 caliper seals are available to repbuild the caliper.
Steve

[RedRocket]

GAH!


I got the master cylinder apart, and cleaned out the goop.

Unfortunately my caliper piston is IN THERE.

I just tried hooking it back up and forcing it out with brake line pressure and it won't budge.

[Tiger]

Unfortunately my caliper piston is IN THERE.

:) Two ways to do this...

1 - Place the caliper on the floor/work bench, piston facing DOWN!!...block off the brake line hose port and use compressed air, via the bleed nipple hole, (nipple removed!!), to push out the piston. PLEASE KEEP YOUR FINGERS OUT OF THE PATH OF THE PISTON!!!!!!!!!

...OR....

2 - Use grease, instead of compressed air to remove the piston from the caliper...SAFER!!!

                8).......TIGER....... 8)

[Tiger]

 :) ALL you need to go...and then some... 8)

http://ridersofvision.net/rovforum/index.php?topic=11860.msg107762

            8).......TIGER....... 8)

[Lucky]

never rule out a brake hose to lock a caliper. the can collapse internaly & hold pressure.  had to replace one on my van last year

[RedRocket]

I have it soaking in brake fluid for the night.

[inanecathode]

There's enough pressure in the MC to force the piston out, it's just when they get old they tend to only move out a little bit then go right back where they were. What i did to fix that on mine is put really quick pressure on the lever, then let it snap back quickly, then just repeat that. Failing that you can use air pressure through the banjo hole, i've also heard of using a grease gun through the bleeder zerk.

[RedRocket]

Well that was a job and half!
A lot of air, and a lot of beating on the caliper with a small hammer, and 30 minutes later it finally squeezed out.  The first seal looked like it got somewhat caught it it the bore.

[inanecathode]

Word, make sure that shit is *cleaaaaaaaaaan* squeaky clean going back in. Any doubts just buy a new piston.

[RedRocket]

Word, make sure that shit is *cleaaaaaaaaaan* squeaky clean going back in. Any doubts just buy a new piston.

My piston looks fine.  I hit with some 1500 paper, and steel wool. 
I just need to find seals.

[musicweb]

Here's the post for the stainless line I got:

http://ridersofvision.net/rovforum/index.php?topic=11606.msg106438#msg106438