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Help figure out this rear brake mess on '87 VR.


jonsmyth

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I have a bizzarre issue where the rear wheel disk rotor is for some reason out of alignment with the brake caliper housing. This has caused the rotor to actually come in contact with the housing, and I do not know how this issue started.

There are clues. First I purchased the bike making a bad clicking noise when the rear brake was applied. Also, then as now, the rear brake pulsates at low speed- or the pulsing is less apparent at high speed.

The clicking went away when I noticed the pinch bolt on the rear axle was loose. When I tightened it, and the axle was secured, the clicking dissappeared. When the caliper was removed, it was obvious the rotor was contacting the inboard (wheel) side of the housing, as it is mounted on the bike.

A local Yammer mechanic said i was probably missing a spacer, but viewing the exploded views of the manual and parts catalog, this is not clear to me that i'm missing anything.

It is possible that the previous owner or his freind Homer left something out when doing a tire change or something. I have used two washers on the caliper housing mounting bolts to offset the housing towards the wheel by 1/16 - 3/32 towards the wheel side, this looks like it has helped.

The Yammer mechanic said the pads are supposed to float, and adjust to the wheel position. The brake is functional. the pads are hopefully "reseating", but all ain't rite.

 

Suggestions, you motor-heads?

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with big washer between the bracket and swingarm- but it pushed the rotor even further into the caliper- so the big washer is now between the "head" of the axle and the swingarm.

This picture is just a try- not how it is now!

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Carl was right, I edit my post earlier should have left it alone. make sure you remove the washers you added to the caliper or you will still have problems. You might have stuck caliper, remember its a floating caliper as well. it will adjust it self to fit the rotor. So if the rotor is rubbing the caliper assembly the caliper will off set itself as well.

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I see a problem with the axle hole on the swingarm. Looks to me like the inside edge is ground towards the outside at the rear of the hole. I know the shoulder of the axle comes through there against the washer, but something just doesn't look right!

 

JMHO

 

Dan

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I see a problem with the axle hole on the swing arm. Looks to me like the inside edge is ground towards the outside at the rear of the hole. I know the shoulder of the axle comes through there against the washer, but something just doesn't look right!

 

JMHO

 

Dan

 

I saw that as well, but figured it might be the camera angle.

Chuck if your swing arm is bad, I have an extra one layed up some where, If I find it you can have it for the shipping cost to you.

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I saw that as well, but figured it might be the camera angle.

 

Chuck if your swing arm is bad, I have an extra one layed up some where, If I find it you can have it for the shipping cost to you.

 

The Angle on the inner side of swing arm is OK, I just looked at mine.

 

Ok, I suggest you completly Remove the Caliper from the bike. and the caliper mounting piece. And the Rear Wheel, and greese everything, includeing the Drive Shaft Forward Spline.

 

That Caliper NEEDS TO BE REMOVED, AND REBUILT!!!! Sorry. Order, Re-Build Kits, and new set of brake pads. You might as well do the left Front side also, as you are going to have to go thru the Replace all the fluid, and Rebleeding process.

 

And you might as well Re-Build the Rear Master Cylinder as long as your at it !!

 

I know, you did not want to hear that. :whistling:

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By the look of your picture your swing arm is screwed. I think maybe somebody before had put the washer in the wrong postion and then to try to line up the caliper they filed off the swing arm. Just my thoughts.

See pictures of a perfect Venture,,, an 85 of course:stirthepot:

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Your swing arm is normal for you year of Venture. I have an 89 and just looked at it and my is cut at an angle also, just like yours. The is a difference in swingarms between the the earlier Ventures and the later first gens. You will also find that the relay arms are different also as the made a change to them in 1988 to those. Anyway the washer goes between the wheel hub and the torsion bar for the caliper. The caliper is mounted securely to the bar and it floats a bit on the axle. I did just rebuild my braking system and I ended up using some washers on the mounting bolts for the caliper to get it spaced out properly to clear the rotor. My rotor is warped a bit also and I plan on replacing it but I had one of the button bolts strip out the allen head on it so I just left it till I could get in the proper bolts for it. The spacers I used where the ones from the brake lines as I upgraded to steel braid lines when I rebuilt the system.

You might also want to take a look at the hole the axle goes thru on the torsion bar as I have seen the very egg shaped. This might be part of your problem. I dont believe the hole is perfectly round from the factory but cant say for sure and this part isnt available anymore from Yamaha.

Hope this helps you a bit and let me know you have other question.

Rick F.

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The swingarm on my 89 also has that angle to it. I wonder if they did that to the MKIIs to facilitate getting that washer in.

 

The rear caliper on my 89 does not float, it's bolted rigidly to the bracket. You can see in jonsmyth's first pic that the caliper does not float.

 

The brake caliper bracket is positioned relative to the wheel by the collar between the bracket and the rear wheel bearing. Either the bracket is bent (seems unlikely) or there is something wrong with the assembly.

 

If it were me I'd be pulling that rear wheel and comparing carefully to the parts fiche. In particular I'd be making sure that the bearing is fully seated and it's circlip in place. The narrow end of the collar points toward the wheel - if it's backwards it won't go in as far as it should (and the oil seal will be ruined).

 

You don't have the axle in on your pic at the end of the swing arm so that may have stuff hanging funny but it sure looks too tight. If you look at the other pics of 1st gens you'll see a small gap between the swing arm and that washer. On the 2nd gen it's a much larger gap.

Edited by MiCarl
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This is going to be crazy, but the wheel looks like it is too far to the left. Isn't there a a spacer that goes in the differental itself???:confused24: I would pull the wheel, remove and inspect every piece, then put it back together. The brake rotor should be in the center of the caliper unless the rotor has been removed and put back wrong somehow.

 

Just my worthless opinion.:080402gudl_prv:

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Your swing arm is normal for you year of Venture. I have an 89 and just looked at it and my is cut at an angle also, just like yours. The is a difference in swingarms between the the earlier Ventures and the later first gens. You will also find that the relay arms are different also as the made a change to them in 1988 to those. Anyway the washer goes between the wheel hub and the torsion bar for the caliper. The caliper is mounted securely to the bar and it floats a bit on the axle. I did just rebuild my braking system and I ended up using some washers on the mounting bolts for the caliper to get it spaced out properly to clear the rotor. My rotor is warped a bit also and I plan on replacing it but I had one of the button bolts strip out the allen head on it so I just left it till I could get in the proper bolts for it. The spacers I used where the ones from the brake lines as I upgraded to steel braid lines when I rebuilt the system.

You might also want to take a look at the hole the axle goes thru on the torsion bar as I have seen the very egg shaped. This might be part of your problem. I dont believe the hole is perfectly round from the factory but cant say for sure and this part isnt available anymore from Yamaha.

Hope this helps you a bit and let me know you have other question.

Rick F.

Same goes for my 89. when i 1st put the bike together after my accident I made the mistake of putting the washer between the wheel and caliper support . The result was the disc grinding on the caliper so I spaced the caliper in with 2 washers. Later I realized my mistake so I removed the added washers and then moved the space washer to the outside of the caliper bracket. problem solved. and yes that angle cut on the swing arm is normal. Make sure you have the right spacer washer though the thick end of the axle should not pass throught the washer.

Here are some pictures of what it should look like note the space between the swing arm and caliper bracket or washer it does not actually touch the bracket or washer as in the MKI.

 

When tightening, tighten the axle shaft 1st then the swing arm pinch bolt last.

Edited by saddlebum
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Now if you put all this info together, you'll come to realize that it doesn't matter on the cut of the swing arm, because it would have very little to do with the position of the brake caliper bracket. You see, the axle goes through the swing arm then through the washer then through the bracket and then into the wheel. The expanded end of the axle will not go through the washer, nor should it go through the bracket. If you put the washer before the bracket then the washer holds the bracket in place and then the axle can be tightened. The right side of the swing arm should not be tightened to the wheel assembly in this process. You will need to snug the pinch bolt to keep the axle from turning so that you can get proper torque, but in the end you loosen the pinch bolt, tap the swing arm and then retighten the pinch bolt, so that the swing arm will position itself without stress to the arm itself.

Now the wheel is held on by the axle, the thick end of the axle pushes against the washer on the one side and the nut and washer hold things at the other side. Virtually then, the wheel is held tight to the left side of the swing arm only, with the right side only keeping the wheel in line.

So it really doesn't matter what the cut is on the right side of the swing arm, seeing as it has 'nothing to do with holding the wheel tight to the bike'.

Hope this helps, rather than create more confusion.

Carl

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I'm thinking that " Clutz " the mechanic was working on that bike, before you bought it. Take wheel, out and inspect everything, as the previous post reccomended.

 

Something is wrong, and its not the angle on the swing arm.

 

 

And be sure to post what you find, feedback is required on this site !!

With pictures !!!

 

:detective::detective:

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for what it's worth; when I bought mine the rear brake disk was shopt as a result of a missing washer. Teh shop didn't realize this untill after they replaced the disk and it had a grinding noise. If you're not missing one, could you have a wrong sized washer, or possibly the wrong size disk?

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