Dragging calipers ??

[turbodude]

I am a bit stumped on this one so hopefully someone here can help a bit.  This is on my 2005 Multistrada 1000DS, but the brake system is similar to Monsters.  

Over the weekend I changed tires which means removing the front calipers from the wheel.  While they were off, I figured it would be a good time to clean out all the brake dust that accumulates in there.  So, I sprayed with 3m brake cleaner & blew out with compressed air.  I reinstalled the caliper and rim, then pumped up front brake.  

Now the front brake is dragging.  If I spin the front tire, it won't even go a full revolution before it stops.  I can feel the extra drag just pushing the bike in the garage.   The lever is very stiff as well.  I don't believe the problem is in the master as it was fine before & I didn't do anything to it.  I did a search and someone here posted that the brake cleaner is not good for the piston seals and may be causing the drag.  I was thinking of removing the caliper again and using something to lubricate the pistons (not sure what yet).  Does anyone here have any ideas?

Thanks for any help.

[DarkStaR]

I run into the same issue after messing with the brakes.

Usually goes away after a ride for me.

Go take it for a cautious ride around the neighborhood, maybe give it a panic stop or two, and re-check.

[VisceralReaction]

^+1
mine drag too after I mess with them and then they are fine.

[turbodude]

Hmm, I was going to do just that, but when I found it was tough just to push in the garage it made me nervous.  Thanks for the feedback guys.

[WTSDS]

Maybe this will help you.

http://www.ducatimonsterforum.org/index.php?topic=46781.msg849359;topicseen#msg849359

[turbodude]

Thanks for the link!  I will have to stop using brake cleaner on bike parts.  I greased up the caliper pistons with dupont white lithium greese with teflon, pushed them in, cleaned them up (without brake cleen this time).  They are much better now.  A little bit of drag, but much better than before.  Haven't ridden it yet, but it should be fine.

[Armor]

I woundn't use grease with brake fluid.

[Howie]

If the white lube gets past the seals you are in trouble.  Only synthetic brake lube designed for brake pistons or brake fluid should be used.  Yes, brake fluid will provide enough lubrication.  If your brake fluid gets contaminated with petroleum product the seals will swell.

[turbodude]

Ugh, should I clean the calipers again (this time with soapy water), then lube the pistons with brake fluid? 

[ducatiz]

Brake lube.  It is made for contact with brake fluid, usually silicon based.

Lithium will actually react with the glycol to produce a very thick gel fluid.  Think very thick soapy crap.



also, if you buy a brake piston kit from brembo, it usually comes with a small packet of grease

[Howie]

Clean with brake cleaner, alcohol or clean brake fluid, not soap and water.

[ducatiz]

Clean with brake cleaner, alcohol or clean brake fluid, not soap and water.

if he removes the pistons, sure..

but while they're installed, the soap/water with a brush method is fine.  I use those nail brushes from autozone..

[turbodude]

Ok so clean with brake cleaner & then use caliper lube as shown above?  (cleaning the calipers with brake cleaner is how this whole mess started.)

Thanks guys.

[ducatiz]

Yes, to get rid of the lithium grease.  But I'm understanding that you are REMOVING the pistons to do so.. flush out the caliper too to get rid of it inside and on the seals.  Wipe everything inside the caliper down wtih brake fluid, dry it and then lube the seals with the grease I posted above (or similar)

[WTSDS]

>>>Clean with brake cleaner, alcohol or clean brake fluid, not soap and water.

What's wrong with soapy water ? ?

My brake problem was due to a collection of grunge building up in the bores and on the outside of the pistons, jamming them together.
Once cleaned all worked perfectly and that was over 2.000 km ago

The pistons were stuck at the outer limit of travel and I did the cleaning after pushing the pistons back into the calipers. By the time I had reassembled things the water would have dried out. There's no reason any water would be able to get past the seals and contaminate the brake fluid. The pistons don't contact the bores, there's an annulus between the two.

I appreciate that using soapy water may not be suitable for cleaning if the pistons are removed, but if I was going to remove the pistons I would replace the seals as a matter of course anyway and use brake fluid for cleaning.