thedeatons

This is a long story. I am at my wits end. I'm ready to send my bike to the dealer and pay money to have then bleed the back brake, but i don't even know if that is the problem... My fear is that they will find something else wrong with the brake system, and that will cost me...

Here is the problem: i got this bike from my dad and the back brake was working intermitently. Seemed like there was air in the line. I removed the rear caliper from the bracket, laid it on the floor, and bled the line. That worked for many months.

Later on i got the rear caliper powdercoated, and installed new seals inside. I bled it after that and it continued to work fine.

Months later i installed an hrc reservoir delete, and bled the rear brake, and that was fine too.

Months after that i bought rear brake pads and installed them. After install i pried the new pads apart and reinstalled the caliper. Very shortly after this the rear brake felt like there was air in the line. I tried to bleed it again to no avail. So i thought this would be a good time to rebuild the master cylinder. I used an oem honda kit with new spring, plunger, boot, and snap ring. It still wouldn't bleed after that.

Next i tried buying a large syringe and good tubing and tried pushing brake fluid through the line. That didn't work. In fact it was extremely hard and slow to push fluid through. After that i tried using the syringe to pull fluid through. That didn't work either.

So here i am. Kinda sick of working on it...

8541Hawk

The first question is Did you clean the caliper piston before you pushed it back into the body of the caliper?

If not , then I would suspect you pushed dirt into the seal area.

The fix would be to disassemble the caliper, clean everything, and reassemble.

thedeatons

I did... That was part of my make it sparkly after powdercoating the caliper routine.... I could put that on the list of things to polish again, assuming I decide to take it all apart again

James

Wicky

Leaky nipple?

thetophatflash

Isn't that a little personal? lol I hook my Mytivac under suction to the nipple with a release wrench already in place then push down on the pedal with my right hand while releasing the nipple. The extra suck seems to help get the bubbles over the hump.

CrankenFine

This sounds like debris at the bleed nipple of the caliper or an impediment in the line itself.

superbeater

It sounds like you know how to work on the caliper and M/C. Carefully disassemble each and check for anything that isn't right. Look for dirt, debris or any thing irregular. Take your time with disassembly so you see any thing strange.
You should be able to push fluid up from the bleeder nipple to the M/C fairly easily.
When you have the nipple out of the caliper, wrap the threads with Teflon tape to reduce leaks (air or fluid) when bleeding.

SIRR1

I am old school and rarely use the rear brake, they scare me really bad!


It's sounds like you know your way around so the first thing I would do is clean the gunk off the bleeding valve to insure a good seal and reinstall then pump the brake pedal quickly using short strokes.


No need to bottom the pedal out each stroke.


Install your fluid drain hose and run most of the clean new fluid through the M/C line and caliper but don't drain the resivore and do this until you have good clean fluid in your drain hose.


Close the valve, top off the resivore and give the pedal several short stokes and you should start to feel pressure build, with pressure on the pedal open and close the drain valve, top off resivore and repeat until you have good pedal pressure.


Wait a few minutes and check for pedal pressure, if its gone repeat the above steps.


If you loose pressure again I would purchase one of those easy bleed valves around $20 bucks shipped and try that if not you may have a nicked O-Ring in your M/C that's allowing air into the system.


Good luck and tell us what the problem ended up being.


SIRR1

Stixx

Maybe look at replacing the brake line. I had front brakes that felt like they had air in the lines. I had not done anything to them to introduce air, tried and tried to bleed them. replaced the lines and problem went away. the only thing I could come up with is that one of them was starting to fail and would swell a little when I applied pressure.

CrankenFine

Have you had any success determining the problem?

thedeatons

No... I haven't worked on it yet. Pretty deep into some other projects. Will go on a group ride tomorrow then may be motivated to play with it...

James

Wolverine

I'm throwing out a hail mary here... the last set of brake pads I bought for our Jeep didn't fit for crap. I had to file them down so they could slide in the caliper bracket itself. Are these new pads having a fit issue? If they don't have the clearance to move after everything is buttoned up, this may be your issue. Just a thought.

smokinjoe73

Wait, your going on a group ride with no back brakes?

Dont ride a bike with iffy brakes unless its to limp it to go get new brakes. And even then know you are taking your (and others) life in your hands.

There is a reason back brakes exist and a reason you would never be allowed on a racetrack without them. They save my hide when my fronts gave out on the track.

FWIW the brake system is really simple and parts available on ebay. You could just replace it.

xeris

I'm thinking more than a hail Mary. The problem started after the install of the new pads. Good call Wolverine.

smokinjoe73

I agree with wofvmans idea but think its more likely a cocked pad. (or otherwise mis-installed). I have mis installed rear brakes often. It can drag and heat up, locking the rear wheel. Even had a buddy experience this on his Aprillia rsv.

thedeatons

Not a brake pad issue at all. The pedal goes down to the stop. No pressure at all in rear brake.


James

ascothawk

Try bleeding it at the master cylinder. It's worked on the clutch and when I installed braided brake lines.

Wolverine

This would make me inspect every o-ring in the master. I would think master has to be culprit, especially if you can't build any pressure.

smokinjoe73

You should spring the 20 bucks to buy an ebay unit til you fix this or just use that one.

I am not overstating it by saying your life may depend on it.

RCVTR

did you replace the reservoir with a short piece of clear tubing, with a plug in it? I think that's the HRC mod you are referring to.

If so, you may have a vacuum lock that is preventing fluid from filling the master cylinder. Remove the plug, then pump the brake until the pads contact the rotor, making sure the reservoir tube doesn't run out of fluid. Once the pads are contacting the rotor, fill the tube, but leave an air gap at the top. Then replace the plug. A longer tube with a bigger air bubble may be required.

thedeatons

Success!!! After working on this for a LONG time, having the caliper off four different times, spraying brake fluid everywhere multiple times, i finally went to the Honda shop.

No i didn't have them do it i found the old guy in the service department. The guy who has never steered me wrong before, and has worked on a lot of machines over the years, and i asked for advice.

I told him i'd been using a large syringe, and was trying to push fluid through from the back, then i tried pushing through from the front. Fluid was moving, no leaks, but for dome reason i had no lever pressure.

I coaxed him into coming outside and looking at it, just to tell me if he thought it could be he hrc reservoir...

After about two minutes he showed me the curly part of the rear brake hose, the part coming off the master cylinder, was pretty high in relation to the caliper. He said i probqbly have an air pocket, and if it was him he would remove the caliper and hold it up high to let the air travel upward to the bleed nipple.

So just now i did that, and set the caliper on the right rear passenger peg while i bled it. I sat my syringe in the hrc tubing, and put pressure out it, and TONS of air came out. So i twisted the caliper all around to try and get any trapped air to the nipple, and more air camr out!

My back brake now works for the first time in a year

Wisdom....

James

kenmoore

What a rigmarole!

Glad to see that you finally got it.

The back brake on the VTR is sad at the best of times.

I do use it to correct my line when over cooking corners a bit but apart from that I find it pretty pointless compared to other bikes I ride.

Did you go on the ride with a back brake?

thedeatons

No, not yet. I've been on plenty of rides without it, both last year and this year. Like you I only use it for trail braking in turns, or as "wheelie control"... That was the only thing that worried me, two-up wheelies getting out of hand and having no fail safe.

James

smokinjoe73

Glad you got it fixed but the sad truth is riding without a working back brake is more foolish and dangerous than you clearly realize.

If wisdom was gained, it would be to never do that again. Back brakes can save your life. They saved mine when my fronts went out at 90mph in the rain.

Wolverine

fixed that for ya.

VTR1000F

Wait, wait, wait, wait, wait. Let me go get some popcorn.

Big_Jim59