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Brake question

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zap427

Member
I used the Lyndall method of cleaning my front calipers because I had to pull the front brake lever about half way before getting any braking. After the clean things were much better in terms of lever travel getting brake within a quarter of lever travel.

The problem, after this cleaning I seem to have more front drag on my rotor then before the cleaning. I know a certain amount is considered normal, but how much is a "little bit"?

Also, what actually pulls the piston back in the caliper when the lever is released?

Thanks
Jeff
 
You shouldn't have more drag after cleaning unless you didn't get the portion of the piston well up inside the caliper.

You should be able to turn the tire with only noticable drag.

As far as what retracts the pistons....not much. When the master cylinder is released there's a small amount of draw back from when the return spring pushes back on the piston but the pads will always be in contact with the rotor.
 
There is nothing to pull the piston back. I relaxes with no pressure. that is the drag. pad barley touching rotor with no pressure. that is normal.:cheers
 
OK, I cleaned them good using a shoe string. I had an old putty knife between the pads to control how much piston was exposed.

In terms of wheel rotation how much do you guys think is normal? I was told with the tire off the ground one revolution of the wheel is normal. Mine do not come close to one rev unless I push the pads in by hand. Of course once I use the brake the pads don't pull back as far.

If the one rev thing is true, the only thing I can think of is that I did not expose enough of the piston while cleaning. I was a bit nervous about having them come out too far.
 
never did the revolution thing. It should touch the rotor with no presure. laying against the rotor. If it is being held against the rotor something is wrong. may be a warped rotor? May be lever is not clearing. Check see if brake light is staying on?
 
No brake light. I can't imagine it being the rotor as I noticed it right after the cleaning. If the pistons sucked back just a bit more it would make a big difference.

The bike pushes fine, no noticeable drag. But there is no where near a full rev with the wheel off the ground.

Thanks
 
Glider,

Well that makes me feel better. I do know the rear spins easier but of course, just one caliper.

The fellow that told me that claims he regularly gets a rev and one half with the tire elevated. This is probably nothing but I do know it changed with the cleaning. Like I said, no problem pushing it by hand and the rotor does not seem to have extra heat build up when I ride.

Thanks
 
zap427 said:
The bike pushes fine, no noticeable drag. But there is no where near a full rev with the wheel off the ground.
Click to expand...

A couple of things:

1. With the top off of the MC reservoir, do you get a little "up-welling" as you apply the brake? You can siphon out some of the brake fluid until it is about 1/4" above the highest point in the bottom of the reservoir. In this case, you should actually see a little "fountain" as you apply the brake. Be gentle so you do not squirt brake fluid out of the reservoir.

IF YOU DO NOT HAVE ANY OF THE ABOVE HAPPENING, YOU WILL NEED TO REBUILD THE MC.

2. If #1 worked out OK, then just run around a bit to see what happens after a few hundred miles. If it stays VERY tight, you may need to rebuild the front calipers.

TQ
 
Zap; I just went out and checked my '07 FLHTC front wheel. I consistantly get 1- 1 1/8
revolution. If I give it a grunt, it goes about 2 turns. My hand is only on the wheel from about 1:00 to 4:00 positions to give the spin. I can hear the pads dragging. The wheel spins the same after I pull the lever hard and release.
 
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