Sticky brake pistons

[McRuss]

I'm having trouble with the front brake pistons/pads not releasing as they should. The front wheel, while it is not locked up, will not spin freely. I've removed the calipers, pushed the pistons out as far as I dared and cleaned them with a heavy cord and some brake cleaner. But they still seem to be sticking.

Any thoughts? Anyone else had this problem?

Oh, 2004 with 33,000 miles, 2nd set of pads, no problem until about 30,000 miles.

 

[Randy]

I'm having trouble with the front brake pistons/pads not releasing as they should. The front wheel, while it is not locked up, will not spin freely. I've removed the calipers, pushed the pistons out as far as I dared and cleaned them with a heavy cord and some brake cleaner. But they still seem to be sticking.
Any thoughts? Anyone else had this problem?

Oh, 2004 with 33,000 miles, 2nd set of pads, no problem until about 30,000 miles.

Have you flushed/filled the brake fluid lately?

Try using a scotch brite pad or emory cloth on the surface of the rotors.

Make sure you clean/grease the front axle every time you remove the wheel.

Make sure you haven't overtorqued the front wheel.

 

[ionbeam]

What Randy said. Then, push the pads away from the rotor and try to spin the front wheel. No spin -- you are looking at a wheel problem. Spin freely -- you are looking at a brake problem.

Assuming it is brake related, and assuming the pistons really are clean, check the following:

* The position and condition of the pad support, the wavy springie thingie on top of the pads

* Check the pad pin for corrosion, roll the pin on a flat surface to test for being bent

*Are the metal shims on the back of the pad missing? Some pads may require you to move the shims from the old pads to the new pads.

*If all the above are good then you will need to disassemble the caliper and clean everything, lube what needs lubing and change the seals.

 

[Warchild]

I'm having trouble with the front brake pistons/pads not releasing as they should. The front wheel, while it is not locked up, will not spin freely. I've removed the calipers, pushed the pistons out as far as I dared and cleaned them with a heavy cord and some brake cleaner. But they still seem to be sticking.
Any thoughts?

Gotta question for you... I bolded the above words that caught my eye: I just want to make sure you are NOT referring to the slight "drag" the caliper pads have on the rotors in routine operation. Because that is completely normal... the caliper pads lightly rest on the rotor surface even when not activated. If you lift the front wheel and try to spin it, you should hear a slight "hissing" sound as the pads gently ride on the rotor surface until the brake lever is squeezed.

Just want to make sure we are NOT talking about that.... or are we? Cause if we are, you probably don't have a problem.

But if you lift the front wheel and find that it takes undo force just to move the wheel, or the wheel doesn't spin at least a good revolution or so if you try to spin it hard, then I concur you have some brake issue here.

Oh, 2004 with 33,000 miles, 2nd set of pads, no problem until about 30,000 miles.

At 33K, have you ever torn down the calipers to clean/inspect?

 

[donaldb]

Oh, 2004 with 33,000 miles, 2nd set of pads, no problem until about 30,000 miles.

At 33K, have you ever torn down the calipers to clean/inspect?

Dale, do you have a tech site w/instructions/pic's of disassembling, cleaning, inspecting a caliper?

 

[Randy]

for point of reference, with the front wheel in the air, i can get about 2 1/2 - 3 revolutions when i give the wheel a good spin.

 

[Warchild]

Dale, do you have a tech site w/instructions/pic's of disassembling, cleaning, inspecting a caliper?

Not for the FJR, but I do for the Blackbird, and the principles are pretty much the same...

Cleaning the Brake Calipers

 

[donaldb]

it asks for a username and a password---will I have to register to view?

 

[radman]

Allow me............

CBR1100XX caliper rebuild

amateurs.............

 

[Warchild]

Allow me............
CBR1100XX caliper rebuild

amateurs.............

I didn't want to use that copy, because the new XX forum software restricts the number of images in any one post, so the last 1/3 of the photos don't show in that link...

Here, lemme just cut-n-past the article over a couple of entries:

-----------------------------------------------------------------------------------

First, you take your MityVac and suck out every trace of old, nasty brake fluid from the brake system as clearly outlined in Chap 15 of your Honda Blackbird Service Manual. Before you crack open your first bleed nipple, suck out the master cylinder until it's bone-dry:

Here is my neglected, nasty-ass crusty left front caliper:

Close-up of the pistons all caked with road splooge from 60,000+ miles of use. Bad Warchild.... dirty calipers, Bad, BAD!! :evil:

Break the caliper halves apart by removing the three caliper body bolts (12mm socket) on the non-piston side of the assembly. Note Honda's use of red loctite on the trailing threads of the bolts. You'll be working the rachet handle to the bitter end:

Pull the pistons out far enough to expose all the crusty brake spoo (yellow arrow) so you can thoroughly clean them. You could go whole hog and replace all seals at this point if you felt so inclined. Me, I elected just to clean the dog-shit out of the assembly, and keep going.

Using a non-petroleum based cleaner, scrub all the crusty road spooge off the pistons and caliper body:

Now flush your shiny-clean piston with clean hydraulic fluid and re-insert it into its respective cylinder:

Now clean out all the old dried, caked-up lube remaining inside the slider pin boots (obviously, replace these boots if they are damaged/torn):

And thoroughly lube up the interior of the slider boots with an appropriate silicone-based grease of your choice (per the manual):

Apply a thin layer of this same lube on your slider pins....

And finally, reassemble these bad boyz:

Although the Service Manual calls for new caliper assembly bolts, frankly, you're safe to use the old ones if they are in good shape, cleaned of old threadlocker, etc. Here I'm applying Loctite Blue to the trailing threads of the caliper assembly bolts prior to reassembly:

Torque these bolts down to 24ft-lbs.... now, don't be dicking this one away!!! :!:

DONE! All cleaned, lubed, reassembled and ready for some new brake pads! Although the Honda factory pads are quite excellent, me, I went with the Carbone Lorraine SBK-3 pads. :twisted:

Bleeding the system with fresh hydraulic fluid is left as an excerise for the reader......

Obviously, with the monoblock calipers the FJR uses, you won't be "splitting" the caliper halves as is shown above. Still, most all other aspects of the job are the same in principle.

 

[donaldb]

pretty strait forward stuff there..............thanx!!

I suppose draining the break fluid dry would make no difference one way or the other w/an ABS system?

 

[Geezer]

If you are concerned about bleeding all of the air out of your system you could flush in some fresh fluid before you take the calipers off. You would then have to figure out how to stop the fluid from draining out once you take the brake lines off of the calipers.

I haven't donre this but I think a couple pieces of rubber held on gently by a small clamp or set of vice grips would work.

 

[donaldb]

Geezer I was wondering the same thing, do you have to drain the system to clean the calipers? is it necessary? or if you have good fluid already in the system how do you remove the calipers w/out loosing fluid and do it in a fashion as to not damage the lines? If that is possible I'm sure you would still need to bleed a little after you re-connect the caliper. But crimping the line? will that work w/out damaging the line? :blink:

I would think it would be possible w/stock lines but not w/stainless. I'm not sure maybe Dale or Radman or someone w/higher mechanical knowledge will come to our rescue.

 

[Ignacio]

for point of reference, with the front wheel in the air, i can get about 2 1/2 - 3 revolutions when i give the wheel a good spin.

That seems in the range of reason to me. I concur that the pads do put a little force on the rotors even when fully disengaged. I remember from an automotive engineering class that it was for a good design reason with piston and seal designs, but memory and Googling don't seem to work for me today.

I do know that the little bit of drag is one of those things that folks out at Bonneville check for before going on high-speed runs. To help that [/i]little bit[/i] they get out a screwdriver out and pry brakes pads away from rotors before each run. At the end of the run they have to pump the brakes once or twice to get them to work.

 

[Geezer]

Geezer I was wondering the same thing, do you have to drain the system to clean the calipers? is it necessary? or if you have good fluid already in the system how do you remove the calipers w/out loosing fluid and do it in a fashion as to not damage the lines? If that is possible I'm sure you would still need to bleed a little after you re-connect the caliper. But crimping the line? will that work w/out damaging the line? :blink:
I would think it would be possible w/stock lines but not w/stainless. I'm not sure maybe Dale or Radman or someone w/higher mechanical knowledge will come to our rescue.

No, no. Don't crimp the line under any circumstances.

I was thinking about removing the line from the caliper and placing a piece of rubber over each side of the end of the line. Then clamp those rubber pieces snug so they seal the fluid into the end. It would be messy to work on until you sealed it up so you'll use some rags and work quickly. Some soft wood pieces might work instead of rubber to make the seal, or maybe bits of wood between the clamp and the rubber pieces to stiffen the rubber.

You still need to bleed the calipers once you put them back on.

 

[ionbeam]

I was thinking about removing the line from the caliper and placing a piece of rubber over each side of the end of the line.

Less than 50 cents from the hardware store.

This is probably one time where a golf tee isn't a good idea :lol:

 

[Randy]

I do know that the little bit of drag is one of those things that folks out at Bonneville check for before going on high-speed runs. To help that [/i]little bit[/i] they get out a screwdriver out and pry brakes pads away from rotors before each run. At the end of the run they have to pump the brakes once or twice to get them to work.

As do the roundy-round NASCAR guys before qualifying

 

[donaldb]

I was thinking about removing the line from the caliper and placing a piece of rubber over each side of the end of the line.

Less than 50 cents from the hardware store.

This is probably one time where a golf tee isn't a good idea :lol:

that's why we keep you around

 

[McRuss]

(Quote Gotta question for you... I bolded the above words that caught my eye: I just want to make sure you are NOT referring to the slight "drag" the caliper pads have on the rotors in routine operation. Because that is completely normal... the caliper pads lightly rest on the rotor surface even when not activated. If you lift the front wheel and try to spin it, you should hear a slight "hissing" sound as the pads gently ride on the rotor surface until the brake lever is squeezed.

Just want to make sure we are NOT talking about that.... or are we? Cause if we are, you probably don't have a problem.

But if you lift the front wheel and find that it takes undo force just to move the wheel, or the wheel doesn't spin at least a good revolution or so if you try to spin it hard, then I concur you have some brake issue here.Quote)

It takes undo force to move the wheel, not an obscene amount but not the soft hiss that the rear makes. The pieces are all in correctly and the axle is fine.

Oh, 2004 with 33,000 miles, 2nd set of pads, no problem until about 30,000 miles.

At 33K, have you ever torn down the calipers to clean/inspect?

No, that is next, thanks for the pictures and stuff. I did clean the pistons but not the pins. Didnt think about that, will give it a shot. May need to remove pistons and replace seals, go whole route.

Thanks to all who gave input/insight.