Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[hogdooz]

I've been reading the posts about braking problems and want to let everyone know what I've found and see if anyone else has run into this.
A few months ago I was working on a Heritage that had a warped front rotor, pulsating, and in general, poor braking. In the process of checking the system and adequately bleeding the caliper which had very oddly worn pads, I decided to check the movement of the pistons. Two out of the four pistons were stuck. And these two pistons were on the same side, so when the brakes were applied, all the pressure was from one side, which warped the rotor. After freeing the pistons, proper bleeding, and a new rotor and pads, the brakes were better than the rider ever remembered.
Since then, every bike I've checked has had at least one piston on each caliper frozen. These are all late model bikes with 10K to 40K miles on them. And, of course, once all the pistons are operating and the system is bled, the brakes are functioning much better.
My wife's 2009 CVO FLTRSE3 with 27K miles on it has had the front rotors replaced once because of drastic pulsing--that was about 7K miles ago. It's now pulsating again. I checked the calipers and one side had two pistons on one side frozen, the other caliper had one piston on each side frozen, and they were opposite pistons. I have freed the pistons, replaced the fluid, and am in the process of getting the rotors replaced again under extended warranty. I'm sure her braking will be smooth as glass as soon as the rotors are installed.
One of the main processes of getting a good, firm, maximum lever pull is proper bleeding. If anyone is interested in the procedure I learned from a Motor Company tech, email me and I'll go through the procedure.
If anyone has info or thoughts on any of this, I will be very interested in what you have.

[Twolanerider]

Since Harley won't sell service parts for the Brembo calipers are you disassembling, cleaning and reassembling or are you using the service kits from the Drag book to replace anything?  I've had perhaps 15 sets of these calipers apart for chroming or powder coating.  That's a disassembly of parts never with their bike in the same place though.  So it's not as if a lot of attention is being paid.  First thing that's done is jam something between the pads and put some air against the brake line hole to pop out the pistons.  Of those several pairs of calipers I've dealt with two had pistons hung so badly compressed air wouldn't pop them out though.

[hogdooz]

So far, clean and reassemble. And so far, all have broken loose with quick lever action or just a little air. I will check them again in 3K-4K miles to make sure they are still free.

[TN]

part of my regular maintenance during tire changes are cleaning brake calipers and pistons with brake system still intact using brake parts cleaner.
I’ve been known to do this between tire changes also. It doesn’t take long and what a difference it makes in braking efficiency. Brembo calipers have no dust boot on the pistons and are subject to sticking.



TN

[Twolanerider]

So far, clean and reassemble. And so far, all have broken loose with quick lever action or just a little air. I will check them again in 3K-4K miles to make sure they are still free.

Should you ever need service parts here are Drag numbers that might help:

Complete rebuild kits with pistons and seals.  Fronts 1702-0117 and rear 1702-0118.

If the pistons are good here's now a kit that's just the seals.  1702-0125 or 1702-0126 for front and rear respectively.

[Hotrod50]

OK, dumb question.  How can you tell if a piston is frozen?

[efrbc1]

Check out www.lyndallbrakes.com and go to the service/tech tab.  You will find a detailed instruction how to clean HD calipers.  I do this about twice a year and brakes are solid and effective.  Costs about $5 and takes about 1/2 hour.

Chris

[CVO2FIXUP]

OK, dumb question.  How can you tell if a piston is frozen?

  How do you tell if the pistons are frozen. X2

[TN]

perform the brake caliper maintenance provided in the link to lyndall brakes at least yearly and you will see for yourself. Like anything after you do it a time or two yer proficiency will improve and so will the braking action. I also like the lyndall pads for the less dust they produce compared to the stock pads. Just take it easy and don't pop the pistons all the way out while performing this task.

[Para Bellum]

 How do you tell if the pistons are frozen. X2

If all of the pistons are frozen, you won't have much (or any) braking; if not all are frozen, you would have decreased braking effectiveness, so you might (or might not) notice having to squeeze harder to get enough braking. So, any time you have the brake calipers off, like replacing brake pads, you can check that the pistons are moving freely.

Or, as TN said,

part of my regular maintenance during tire changes are cleaning brake calipers and pistons with brake system still intact using brake parts cleaner.
I’ve been known to do this between tire changes also. It doesn’t take long and what a difference it makes in braking efficiency. Brembo calipers have no dust boot on the pistons and are subject to sticking.

.