Foot Brake Problem -88 VR

[safetyguy]

I was bleeding my brakes per the Service Manual - right front, left front, rear, and the one on top. I installed SpeedBleeders on the left front and the rear as I went along. Everything worked as per normal -- fluid came out exactly as expected.

 

No problems until I tried to bleed the one on top. Nothing came out - no air, no fluid, --nothing. I went around to the left front and nothing came out from there (even though it did a few minutes before). Likewise for the rear caliper bleed valve (which worked before). Hey, at least the right front works perfectly.

 

Everything is like it came from the factory -- I never delinked the brakes or did any brake upgrades on this VR. The brakes were working fine before all of this. I just wanted to do some flushing for maintenance reasons.

 

My guess is that there is something going on with the rear master cylinder. I searched the forum but nothing turned up that is exactly like this problem.

 

I am open to suggestions before I begin surgery on the patient ....

[Venturous Randy]

You did refill the reservoir didn't you?

RandyA

[safetyguy]

You did refill the reservoir didn't you?

RandyA

 

as Tweety Bird said once, "I did, I did!"

[bongobobny]

Hmmm, try the rear again, and if you get fluid there, the rear master is probably OK. Instead I would look at the proportioning valve or the metering valve having a piece of junk blocking them. The proportioniong valve is bolted onto the rear master cylinder, and the metering valve is bolted onto the frame near the battery just before (or is it just after) the bleeder on the line...

[safetyguy]

The problem is nothing is coming out of the rear bleeder or the left front either.

 

As a first attempt, I was thinking of applying a little suction on all the bleeders to see what that would do. However, you are making it sound like I should start disassembling and cleaning.

[Rocket]

The problem is nothing is coming out of the rear bleeder or the left front either.

 

As a first attempt, I was thinking of applying a little suction on all the bleeders to see what that would do. However, you are making it sound like I should start disassembling and cleaning.

 

Go for the suction first, as there could be a lot of air from the bleeder changeout.

 

Also get a plastic turkey baster, file or cut off the ridge off the very bottom & discard the squeeze bulb. Thread the baster tube into the filler hole & you will have more fluid capacity for bleeding. I usually fill the tube up, when doing a brake flush.

[safetyguy]

Problem solved.

 

I used a vacuum brake bleeder on the left front bleeder. After about 20 seconds under vacuum, a lot of air came out and things started to flow freely. I used suction on all the other bleeders and pulled a few more air bubbles out of each.

 

I then did a normal brake bleed/flush sequence after that, and everything is just fine now.

 

Moral of the story - it may be wise to vacuum bleed the brakelines first when you do something that opens up them up - like put in Speedbleeders.

 

Thanks for the suggestions and ideas!

[skydoc_17]

Speed Bleeders are a useful little do dad if your braking system is COMPLETELY FULL OF BRAKE FLUID, but if you have air in the brake lines, like right after you install the Speed Bleeders, when you compress the foot pedal, or squeeze the right front brake lever, the air in the line compresses, but there is not enough fluid force to open the ball valve in the Speed Bleeder to allow the air to escape. With the extra force of the Vacuum Pump, you were able to get enough brake fluid to the Speed Bleeder to open the one way ball valve. Once the system is purged of air, then the Speed Bleeder works okie dokey. I'm a little old fashion about bleeding brakes, I like a clear plastic tube on the standard bleeder valve, and the tube submerged in a bottle of brake fluid. You can see the fluid moving, and you can see the air bubbles coming out of the brake line. For someone that doesn't bleed their brakes often, Speed Bleeders can make a bad situation worse. If you have rebuilt a Master Cylinder, or replaced a front or rear caliper, you might do better to install a standard bleeder valve in the brake system until you get good fluid flow to the caliper, or from the Master Cylinder. If the Speed Bleeder allows the owner of a motorcycle to flush his braking system more often, then I am all for them. BUT there are times when a Speed Bleeder will compound a pesky brake job into something worse.

Earl

[safetyguy]

Earl:

 

I discovered what you just said to be the case. If you have a Mityvac (or the Harbor Freight $25 clone) and use it after the initial install, Speed Bleeders seem to work as advertised.

 

The problem was I couldn't figure out how to bleed the left front brake with a traditional bleed valve by myself the other night- my arms weren't long enough to tighten the bleed valve while keeping pressure on the foot brake after pumping and I didn't have a second person around to make the operation work. So since I had some SpeedBleeders sitting on the shelf, I said why not give them a try.

 

Once they are bled properly (with no air issues), I think that there may be some advantages to Speed Bleeders. With them it seems like you can pump your brakes pretty quickly and some real tiny air bubbles come out. I am not sure that these tiny bubbles would have come out from traditional bleeding techniques and they weren't coming out under vacuum either. Of course this is a one time observation and not a scientific conclusion. This is a debate for another thread though ....

 

If I had to do it again, I probably would just install a single Speed Bleeder on the left front and use traditional bleed valves everywhere else. With this setup, one person can bleed the brakes alone.

 

Mike

[camos]

I'm a little old fashion about bleeding brakes, I like a clear plastic tube on the standard bleeder valve, and the tube submerged in a bottle of brake fluid. You can see the fluid moving, and you can see the air bubbles coming out of the brake line.

Me too, old fashioned that is. Never had a problem getting the air out but haven't had that much experience at it either. Bled the brakes on two different cars and 3 different bikes without a problem. Mentioned this once before on this forum and got no response so figured I managed to offend someone. Perhaps I'm just lucky but anyway, thought I would mention it again cuz it seems to work and the topic has come up.

 

Attach a clear hose to the bleeder that goes up 3" to 6" before turning down into a bottle with some brake fluid covering the end of the hose. Crack the bleeder then pump the master cylinder. Fluid will rise in the tube to the top of the curve before running down into the bottle. Any air bubbles can easily be seen as can the colour of the fluid if all that is being done is to replace the old fluid. As long as a little time is allowed for any air bubbles to make their way to the top of the curve, there is no problem with sucking anything significant back into the bleeder while pumping so I have found it is not necessary to tighten the bleeder between pumps. Just make sure the hose is properly sized so it grips the bleeder valve securely. Once all you get is clear fluid with no bubbles, tighten the bleeder and move on to the next segment or bleeder valve farther away from the MC.

 

For what it is worth, that has been my experience.

[big dude]

Hey guys this post is what i needed to read. The wife an I just did weekend trip in southern

indiana,a day out from home, I had to rely on front brakes only man!!!what a trip... I'm gonna start by bleeding brakes but ive forgotten the order in which to bleed can you guys refresh my memory? handle bar area (i forgot name of) then left front ,then rear? i have a vacum pump. :confused24:thanks

[pmelah]

big dude i dont think it maters i started at rear then to left front then to slave and i have great L/F brake and rear good clutch slave now i have to do right front all with the vac:detective:

[big dude]

If i remember right 1st gen has an order to bleed for quicker results

[VentureYZ]

If you are bleeding the front brakes with standard bleeders and are by yourself, pump them up, tie a stiff rubber band around the handle bar and lever to put pressure on the lever. Then crack the bleeder loose and let the rubber band pull the lever till it bottoms out and snug the bleeder down.

 

Mike Allen

[big dude]

squidley you helped me before on my rear brakes can u chime in here an refresh my memory.

[Squidley]

squidley you helped me before on my rear brakes can u chime in here an refresh my memory.

 

Mike,

 

How I usually do it is like this, I bleed the rear caliper 1st off, get solid flow out of it, if using a vacuum bleeder. Then I will go up top by the steering head (on the MKII's) and bleed there. Go down to the left front and bleed that. If it's a 1200 I'll tackle the anti dives after the front left caliper, this is all with a vac bleeder.

 

I'll then do an old fashion petal bleed, pump it up hold pressure and crack the bleeder. I'll do this several times until I get a solid flow of fluid out of the bleeders. I like to use clear hose so I can see if any bubbles are coming out.

 

It can get a bit tedious as it sometimes will take a bit of time, but I never have to worry about if the brakes are right or not. A vacuum bleeder is a must if your going to do brake fluid maintenance on your bikes, be it 1st or 2nd gens. I do the same things when I bleed a clutch, vac bleed it, and then old fashion pressure bleed.

 

Give me a call if you run into problems, my new # is in my profile

[big dude]

thanks Brad, I value your experience your skills, an friendship..

[big dude]

pulled side cover off today first chance i've had , just pushed down on pedal an watched fluid drip from push rod. time for a build kit. pmed skydoc for kit but he hasnt got back with me yet.. searched web seems they have kits for 1200 83 85 not for 86.. any suggestions

[frankd]

Mike,

 

It is available from the dealers----this is my local dealers page, but wherever you buy your parts from will have it....

 

http://www.richsyamaha.com/pages/OemParts#/Yamaha/XVZ13DS_-_1986/REAR_MASTER_CYLINDER/XVZ13DS_(1986_MOTORCYCLE)/REAR_MASTER_CYLINDER_(XVZ13DS_-_1986)

 

UPDATE--I just clicked on the URL above, and it doesn't quite work right. You have to clear out the 'try again' message, and then enter the bike data (motorcycle-1986-xvz13dc-rear master cylinder).

 

It's item #2, and the p/n is 4W1-W0041-00-00. Google the p/n and tons of places that have it show up.

 

 

Skydoc is very busy---he's still moving. He has been answering his emails when time is available.

 

Frank D.

Edited August 26, 2012 by frankd
prompt didn't work correctly

[Squidley]

pulled side cover off today first chance i've had , just pushed down on pedal an watched fluid drip from push rod. time for a build kit. pmed skydoc for kit but he hasnt got back with me yet.. searched web seems they have kits for 1200 83 85 not for 86.. any suggestions

 

 

Mike,

 

This is just my experience, and isn't the gospel, but I have found that trying to rebuild a rear brake cylinder or clutch slave doesn't always work out so good. If you decide to go this route, make absolutely sure that the inside bore and all machined surfaces are spotless, zero pits or defects. I have done a couple and it seems that the material that was used is one step above pot metal. I have only had a 50% success rate with rebuilding them and have attempted 6.

 

If a new one can be had, I would spring for a new one. I replaced the clutch slave on my '86 with a new one because of all the failures I have had in the past with them...

[big dude]

HEY BRAD DID REBUILD today seemed to bleed out real good.. mc was slick.. the 26 yr old rubber piston gave up the ghost.. no seat time on it yet..I was wondering if u have heard of anyone making some kind of heat shield for the resivour? It's only one inch from exhuast pipe, as u know..no wonder they get to boiling easy ...been down that road coupla times.. not lol

[Squidley]

I was wondering if u have heard of anyone making some kind of heat shield for the resivour? It's only one inch from exhuast pipe, as u know..no wonder they get to boiling easy ...been down that road coupla times.. not lol

 

Mike,

 

I personally haven't heard of a heat shield being made for that area. I believe the key to all of that is to keep the fluids changed out on a regular basis. This will insure that the return orifice in the m/c will stay clear and allow for the thermal expansion of the brake fluid. It will also lessen the possibility of moisture building up in the system causing corrosion and all sorts of other havoc.

 

Glad to hear you got it done though, now go enjoy the fruits of your labor