Author Topic: v11 lemans rear brake again NEAT FIX (Read 7166 times)

dl.allen · « **on:** July 02, 2015, 10:55:01 PM »

So my rear brake is dragging so I took it off and took the pads off. They still looked good and had life left. I cleaned the caliper area really well with brake cleaner and put it back to together. Then I bled new fluid though it with a vacuum bleeder. All seemed to go well. Put it back on. Brake pedal seems good etc. Still drags. Obviously the cylinders are not retracting. What should I do next? I havent taken the cylinders out I don't know how they work. Rotor not warped.
Thanks

dxhall · « **Reply #1 on:** July 02, 2015, 11:14:30 PM »

There are two rubber seals in those calipers - an outer, thinner one which acts as a dust seal, and an inner, thicker one which both (1) seals against the fluid behind the piston and (2) helps the piston retract when the brake is released. When the inner seal loses elasticity, it loses its ability to twist and untwist and doesn't pull the piston all the way back. Thus, the pad drags. If you've cleaned the inside of the caliper and the pads still drag, your inner seals are bad.

You probably won't be able to find new seals. When I rebuilt the calipers on my '98 Ducati last winter, I was told that Brembo doesn't sell seal kits in the US for fear of lawsuits. I was able to find kits for the fronts through an English seller on ebay named "powerhouse," or something like that.

dl.allen · « **Reply #2 on:** July 02, 2015, 11:19:33 PM »

I haven't taken the pistons out. Just cleaned behind the pads. Should I remove the pistons to inspect the seals and clean behind there? How is that done?

dl.allen · « **Reply #3 on:** July 02, 2015, 11:38:35 PM »

Is this the seals I need? Brembo P32B?

http://www.oppracing.com/product_display/30952-brembo-oe-brake-caliper-seal-set-32mm-seal-set-p32b/

Wildguzzi.com · « **Reply #3 on:** July 02, 2015, 11:38:35 PM »

Moto Fugazzi · « **Reply #4 on:** July 03, 2015, 12:46:24 AM »

I don't know if that's the kit you need, but MG Cycle sells new calipers for about $123.00 http://www.mgcycle.com/index.php?main_page=product_info&cPath=110_115&products_id=2510

The rear brakes on both of my V11's seem to drag, as well as my 2009 V7C. I never had warped rotors, but I usually have to change the pads every 10k miles or so, even though I don't use the rear brakes nearly as much as the fronts.
Ken

rodekyll · « **Reply #5 on:** July 03, 2015, 01:50:20 AM »

Be sure the caliper is centered on the rotor. It often needs shims to do that. I'm currently using 0.060 shims to get mine right. Without them the pads drag.

Chuck in Indiana · « **Reply #6 on:** July 03, 2015, 08:38:07 AM »

Our Internet is down, so no way am I pecking an answer on the fone, but it's a known issue. Search v 1 1 Lemans .com

twhitaker · « **Reply #7 on:** July 03, 2015, 08:46:10 AM »

You might check to see if the master cylinder is adjusted such that it is vented when the brake pedal is released.

dl.allen · « **Reply #8 on:** July 03, 2015, 12:43:03 PM »

new caliper ordered so I can get back on the road.
Also ordered the seals so I can rebuild the old one.
Then I can swap them every 3000 miles apparently.

How do I see if the master cylinder is venting?

Steve Scott · « **Reply #9 on:** July 03, 2015, 02:54:26 PM »

With the master cylinder cap off, CAREFULLY activate the brake lever. The reason I capitalized 'CAREFULLY' is because if the master cylinder is 'venting' correctly there will be a squirt of fluid into the reservoir at the very beginning of the master cylinder's movement. It's good practice to have a rag at the ready.

I don't know how your rear brake system is configured, if it's a remote master cylinder the 'squirt' might just be a little turbulence. Unitized master cylinders like many fronts (and most cars) can squirt a couple inches.

There is a little hole in the master cylinder where the reservoir connects. This hole must be uncovered by the piston when it is fully retracted. This allows fluid to fill the system to compensate for pad wear, and it also allows system pressure to 'vent' back into the reservoir as the fluid heats and expands. In an attempt to improve brake performance, it's not uncommon for master cylinders (usually the front) to be adjusted so that the master cylinder piston does not retract far enough, and the system pressure cannot escape back into the reservoir, I've done it myself. The general result is that the brakes drag, and they get worse from the heat of that dragging.

Steve Scott · « **Reply #10 on:** July 03, 2015, 03:04:34 PM »

Another simpler test would be to crack the bleeder when the brake is dragging and see if it lets go.

If it does, then that's a sure sign that the system cannot vent back into the reservoir.

pat80flh · « **Reply #11 on:** July 03, 2015, 04:35:11 PM »

Quote from: Steve Scott on July 03, 2015, 03:04:34 PM

Another simpler test would be to crack the bleeder when the brake is dragging and see if it lets go.

If it does, then that's a sure sign that the system cannot vent back into the reservoir.

This can also be a symptom of a collapsed brake hose

dl.allen · « **Reply #12 on:** July 03, 2015, 08:35:43 PM »

thanks for the explanation. That all makes sense.
I will test the new caliper for retraction then I can go after the master cylinder if it still isn't.

Thanks again. Will report back in a few days when I get the new caliper on.

earemike · « **Reply #13 on:** July 04, 2015, 03:45:31 AM »

Glad you're on to it.

Previous owner of one of my bikes had to replace the disc because he cooked it with a dragging rear pad. Fairly common occurrence if you don't use the rear much I believe.

Let us know how you go for future reference.

dl.allen · « **Reply #14 on:** July 10, 2015, 12:49:50 AM »

So..... new caliper
bled with vacuum bleeder and then with pedal multiple times
long pedal throw but firm
works perfectly on bike stand
go for short ride and it dragging and heating up!
I'm at a total loss as to what to do next
everything seems to be acting correctly so there must be air still in there
any last ideas before I see if the honda shop will fix it for me?

earemike · « **Reply #15 on:** July 10, 2015, 01:22:37 AM »

Quote from: rodekyll on July 03, 2015, 01:50:20 AM

Be sure the caliper is centered on the rotor. It often needs shims to do that. I'm currently using 0.060 shims to get mine right. Without them the pads drag.

I'd double check this next, sorry that's not a great help

malik · « **Reply #16 on:** July 10, 2015, 01:24:04 AM »

The rotor is centered between the pads, isn't it? I once replaced the front tyre on the V7C and swapped the spacers around by mistake. Significant drag. Solved when I went over what I had done before. Could have sworn I had the spacers in properly. Didn't. The V11 has a different spacer system - is there's anything on the wheel that can be reversed there, or not set fully home, to cause the rotor to sit a tad off-centre?

Mal

earemike · « **Reply #17 on:** July 10, 2015, 01:59:09 AM »

Quote from: malik on July 10, 2015, 01:24:04 AM

The rotor is centered between the pads, isn't it?

I'd have thought the caliper should be centred first, you've a pre-existing problem so perhaps the fault isn't the caliper itself.

If you check the gap between caliper and disc at both front & back you'll know if the caliper is parallel to the disc and if the disc is centered. Beyond that I bow to the forum experts.

voncrump · « **Reply #18 on:** July 10, 2015, 03:24:51 AM »

I have seen this problem caused by overfilling the reservoir, try it with the reservoir only half full.
A bit of heat from using the brake expands the fluid and if there is not expansion room in the very small reservoir it can cause dragging which then rapidly heats the fluid and makes the problem worse.
Cheers, voncrump

Testarossa · « **Reply #19 on:** July 10, 2015, 04:44:34 AM »

I've seen a front brake drag because a wheel bearing was improperly seated -- wheel spun true but was a bit off center. This might not be possible with a rear wheel but check it because your problem recurred after the bike settled back onto its suspension.

smdl · « **Reply #20 on:** July 10, 2015, 04:53:46 AM »

Does it use a rubber brake hose or braided steel line? If the former, the hose could be collapsing internally when pressure is released, preventing fluid from returning to the master cylinder.

Cheers,
Shaun

dl.allen · « **Reply #21 on:** July 10, 2015, 08:58:23 AM »

Thanks for replies
rode it around again without hitting back brake and its cool so it centered and not dragging until I apply the brake.
I definately have a full resevoir and will try it half full.
also will try hanging weight on pedal over night and have caliper off and up as high as possible.
then will bleed one more time.

cruzziguzzi · « **Reply #22 on:** July 10, 2015, 10:39:22 AM »

Quote from: Steve Scott on July 03, 2015, 03:04:34 PM

Another simpler test would be to crack the bleeder when the brake is dragging and see if it lets go.

If it does, then that's a sure sign that the system cannot vent back into the reservoir.

I like this ^^^ to see if there is in fact a problem. I didn't see yet whether you note the "drag" to be constant or intermittent as in rotor issues - probably up there somewhere and I missed it.

You might try beveling the leading edge (rear) of the pads.

There's a continuous contact - ever so slight - on my Sportster , front & rear and beveling the edges made quite a difference.

Todd.

rodekyll · « **Reply #23 on:** July 10, 2015, 03:15:45 PM »

A quick and clean way to reduce the fluid level in the cup is to wick it out with a paper towel.

Quote from: dl.allen on July 10, 2015, 08:58:23 AM

Thanks for replies
rode it around again without hitting back brake and its cool so it centered and not dragging until I apply the brake.
I definately have a full resevoir and will try it half full.
also will try hanging weight on pedal over night and have caliper off and up as high as possible.
then will bleed one more time.

Not a valid test of centering. Centering is an eyeball thing. You're looking for the caliper (the fixed part) to be centered on the rotor, not for the pads (the variable part) to be centered on anything. On my calipers the seam where the two halves split make a good centering index.

A 'drag' test is to raise the wheel, insert a feeler gauge between the pad and rotor and work the brake and turn the wheel as you 'feel' with the gauge. The friction will tell you which pad is sticking and how much/when.

smdl · « **Reply #24 on:** July 10, 2015, 05:42:22 PM »

Quote from: cruzziguzzi on July 10, 2015, 10:39:22 AM

I like this ^^^ to see if there is in fact a problem. I didn't see yet whether you note the "drag" to be constant or intermittent as in rotor issues - probably up there somewhere and I missed it.

You might try beveling the leading edge (rear) of the pads.

There's a continuous contact - ever so slight - on my Sportster , front & rear and beveling the edges made quite a difference.

Todd.

I agree with confirming if you have a residual pressure issue. If you crack the bleeder and suddenly the caliper releases, you can start working your way back up to see where the problem is (hose, MC, etc.). That is, of course, unless you have already determined that the issue is caliper alignment!

Good luck.

Shaun

bmc5733946 · « **Reply #25 on:** July 10, 2015, 05:55:18 PM »

People sometimes move the stop bolt adjustment for the brake lever and cause this problem. This bolt touches the lever and sets the level of the toe piece, it should not be adjusted without adjusting the piston actuating rod as well. The bolt may also have collected some road debris thus holding some pressure on the piston.

Brian

Tom · « **Reply #26 on:** July 10, 2015, 11:59:33 PM »

:1: on the good advice. I've been stumped on one of my front calipers hanging up on one of my 1100 spots.

dl.allen · « **Reply #27 on:** July 11, 2015, 05:15:19 PM »

So hopefully problem solved.
After more bleeding and checking everything mentioned here it was still working fine on the stand.
Went for a couple mile test ride, came back and hot!
Had my kid help me pump the pedal while I got down there 2 inches away with my best reader glasses.
One side was moving in and out the other was not! Kid was pumping away and I by luck I noticed the seam between the brand new caliper halves was leaking! I guess that explains why it was working on the stand but under heavier pressure it clamped once then sucked air. So...waiting for an exchange and will try again.

Worked on the old one just for boredom. It was likely just sticky and gummed up. Hopefully reporting back soon with working brake!

Tom · « **Reply #28 on:** July 12, 2015, 05:01:24 PM »

dl.allen · « **Reply #29 on:** July 17, 2015, 07:23:20 PM »

SOLVED!

took brake back apart cleaned the anti seize off.
bent the retainer spring almost flat so it would impart more pressure on the pads and lubes everything with high temp synthetic brake pin lube from napa.
no more drag!
Rotor cool to the touch
thanks for all the input

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Author Topic: v11 lemans rear brake again *NEAT FIX* (Read 7166 times)

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Author Topic: v11 lemans rear brake again NEAT FIX (Read 7166 times)