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Left fork tube leak at dust cover.


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My wife and I own a 1984 VR that we bought almost 4 years ago. It's a fantastic machine that my wife and I ride only a few hundred miles during Edmonton's short summers. The bike has 74K MILES (US-spec'd bike).

 

Yesterday I went to ride the bike and saw some oil on the floor underneath the end of the left fork tube. I determined that there is a slow leak at the left fork tube dust cover. If you look closely, you an see the oil track down the center of the tube.

http://i2.photobucket.com/albums/y35/Tony1M/leftforkleaking.jpg

 

I've never worked on a motorcylce fork, so I read Freebird's excellent tech library article:

[ame=http://www.venturerider.org/forum/showthread.php?t=496]Fork Seal Replacement - VentureRider.Org[/ame]

 

I think I understand how to do the job, but, before I start the job, I'd like to determine if our bike already has progressive springs. The previous owner was very conscientious about maintaining the bike (it still looks in near-new condition), so it is quite possible that he installed progressive springs at some point.

 

As I said, my wife and I ride the bike. I weigh about 285 and she about 130 (her precise weight is a closely-guarded national-security secret), so the bike is carrying 415 lbs of passengers. As far as I can tell, the travel of the fork does not bottom out during normal driving over some fairly substantial bumps. In short, the bike handles beautifully. How can I tell if the bike has progressive springs?

 

I assume that I should also replace seals in the side that is not now leaking. Tell me if I'm wrong.

 

How long should it take a savy newbie to replace the fork seals? How much longer, and how much more effort, if the springs are also replaced? (FWIW, I've rebuilt the carbs and the bike runs great, and I personally perform all of the maintenance on our 92 Accord [that we bought new], so I have some mechanical aptitude. I also have the "official" Yamaha service manual for the bike.)

 

Also, I would say maybe 25 mls of oil have leaked. How much oil can I lose without noticing a change in handling? Can/should I still ride the bike while waiting for parts?

 

Thanks for the advice.

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Factory springs are pretty soft. If you push it a few feet and grab the front brake the OEM springs will let the nose dive quite a bit. This is one of those things though that I'm not sure you'd be able to tell without having tried both............ A lot of the rider weight and all the passenger weight end up on the rear spring.

 

If you're running any air pressure in the front forks you probably have stock springs. Progressives are plenty stiff (many say too stiff) with no air in them

 

Best way to see what springs you have is to pull one out. Put bike on center stand, put a jack under the front of the oil pan to support it. Loosen the top pinch bolts on the fork you want to pull the spring from. Loosen the fork cap (I believe it's 17mm hex drive). Remove the fork cap holding some pressure on it as the springs have some preload.

 

After you have the spring out (it'll be dripping oil so have some rags or towels to wipe it as you pull it) look at it. The distance between the windings in a progressive spring is smaller on one end than the other. Stock springs have evenly spaced windings that I recall being about 2-2.5 cm.

 

Now, my 89 has springs in it that are not stock, and are not progressive. The wire is much heavier gauge than stock and the windings are much closer together (about 1-1.5cm). They are much stiffer than stock, and are a bit harsh. We ride 2 up at similar weight to you with no air in them.

 

If it's pooling on the floor you have a rather significant leak, typically they start by leaving dirty oily rings on the upper fork tubes. I would be leery of riding it. Aside form the damping provided by the oil the air pocket above it acts as a spring. More air = less spring rate means the sides are not the same and the axle will tend to twist with load.

 

When you do the seals do new bushings (sliders) and o-rings on the cap bolts.

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Stock springs have evenly spaced windings that I recall being about 2-2.5 cm.

 

The springs that were in my 83, which I got with 23,000 miles on it, and a set that came out of an 86 parts bike, all have the springs that on one end the windings are close together and the other end farther apart. I thought this was stock.

This would also be a good time to check, clean and regrease your steering head bearings.

RandyA

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1. Just leave the old fork seals in and put new ones on top of the old ones and super glue new ones in around the outside edges. Super glue the dust seal to the new seal.

2. Add 1/2 to 1 ounce extra 10 wt. fork oil. to stop the bottoming out after draining the old.

3. Run 12-15#'s air in front forks.

4. Cheaper, easier & faster to install, lasts longer...:confused24:

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Thank you all very much for your information, directions, and advice about riding.

 

I guess I will not ride the bike until I do the maintenance, so this means I've got to get my butt in gear and get the job done..

 

The first thing I'm going to do is de-pressurize the fork. To tell you the honest truth, I don't know if there is even 1 lb of pressure in there! But I will know shortly after submitting this post.

 

I have to admit that I am intrigued by the following post:

1. Just leave the old fork seals in and put new ones on top of the old ones and super glue new ones in around the outside edges. Super glue the dust seal to the new seal.

2. Add 1/2 to 1 ounce extra 10 wt. fork oil. to stop the bottoming out after draining the old.

3. Run 12-15#'s air in front forks.

4. Cheaper, easier & faster to install, lasts longer...

 

5bikes, I assume that the fork still has to be disassembled in order to install the new ones on top of the old ones, correct?

 

Is the primary reason for doing this that the "stacked" seals (new seal on top of old seal) will not leak for a longer period of time, or miles, into the future than simply replacing the old seal with a new one? If that is indeed the case, then I would be interested in doing this, but I have a couple of additional questions that I hope you will answer.

 

1. Why do the new seal and dust cover have to be super glued when neither the old seal nor the dust cover had to be super-glued when they were originally installed - in the case of our bike, possibly as long as 25 years ago?

 

2. To me, a good picture is worth at least a thousand words. Do you happen to have a photo or two that you could post on which you show exactly where to put the super glue?

 

Again, thanks very much for the assistance, guys. If I remove the spring, I'll post a photo of it. Then maybe you can tell me for certain if it's progressive or not.

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There is zero psi in the front forks.

 

I did not release pressure, so this is the way it has been for at least this year and probably long before.

 

(I assume that this, together with the fact that the bike's front end does not seem to bottom out, at least somewhat supports the notion that the bike may already have progressive springs.)

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See for yourself. Our bike's front fork has no air valve. None under the removable plastic cover, and none anywhere I can see on the fork or tree.

http://i2.photobucket.com/albums/y35/Tony1M/noairvalve.jpg

 

Now what? Did some 84s not have air suspension front forks, even though there is "front" seemingly available on the CLASS display?

 

Thanks for any information.

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be carefull, i just bought my 88 and both fork seals are leaking, im running the bike to work daily and notice a pretty significant shimmy when i relax pressure on the handlebars , and its real loose in the turns, which brings me to my next questrion, who sells a fork rebuild kit and progressive springs

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The Schrader valve you are looking for is to air the forks on a non-Royale. On the Royale they are plumbed to the air pump/valves and controlled by the CLASS system.

 

Might be interesting to put the CLASS in manual mode and see if you can run them up to 5 PSI. That way you can be sure the gauge is reading pressure. Then put them back to 0 before pulling apart.

 

I believe under the caps you'll find a spacer. After you pull the spacer you might have to fashion a hook to get the spring out (depending on how fat your fingers are). There should be a spring seat sitting on top of the spring. Don't loose it.

 

There is no way I would superglue seals and dust seals in. You don't know what you've got, disassemble them and rebuild them right.

 

C'mon. Let's see a pic of the spring!

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The Schrader valve you are looking for is to air the forks on a non-Royale. On the Royale they are plumbed to the air pump/valves and controlled by the CLASS system.

 

Might be interesting to put the CLASS in manual mode and see if you can run them up to 5 PSI. That way you can be sure the gauge is reading pressure. Then put them back to 0 before pulling apart.

 

I believe under the caps you'll find a spacer. After you pull the spacer you might have to fashion a hook to get the spring out (depending on how fat your fingers are). There should be a spring seat sitting on top of the spring. Don't loose it.

 

There is no way I would superglue seals and dust seals in. You don't know what you've got, disassemble them and rebuild them right.

 

C'mon. Let's see a pic of the spring!

 

THANK YOU!:happy65:

 

Unfortunately, as you might be able to see in that last photo, to have enough room to get at the top of the fork and the fork pinch bolts (particularly the driver's right one which has a hazard switch bolted to the right "grill"), I had to remove the large plastic pieces of the "dash" into which the radio/intercom and CLASS control consoles sit. (Yes, the bike needs some coolant in the expansion tank.)

http://i2.photobucket.com/albums/y35/Tony1M/progress.jpg

 

So I'm going to assume that the pressure in the front fork is indeed zero as the CLASS previously told me. After I remove the front wheel, I'll remove the drain screw very slowly and pray that it doesn't come flying out of there with a stream of oil right behind it.

 

Unless there is another way to do it (please tell me there is), I'm going to have to go somewhere tomorrow to buy a 1/2"-drive, 17 mm male hex socket in order to remove the fork caps. That means I'm not going to be able to get the springs out tonight, so tomorrow will be the earliest I can post photos of the spring.

 

Tonight I'll try to get the brake calipers, front wheel and fender off the bike.

 

Sites like this are invaluable to us owners of obsolete (but absolutely fantastic) machines, don't you agree?

 

Thanks very much for the assistance. I really appreciate it.

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I used a bolt with a 17mm head(or 11/16, I can't remember), and I just welded the threaded end into a piece of 1/2 inch square tubing. I made it about a foot long. Then, I just stick a half inch drive ratchet in one end. Works like a charm.

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I used a bolt with a 17mm head(or 11/16, I can't remember), and I just welded the threaded end into a piece of 1/2 inch square tubing. I made it about a foot long. Then, I just stick a half inch drive ratchet in one end. Works like a charm.

 

The torque spec on those caps is pretty low. Should be able to get away with a bolt that has a 17mm head and jamb a couple of nuts on it.

 

While you're at the hardware store get yourself a 3' piece of half inch threaded rod and 4 nuts. Jamb 2 nuts together on each end of the rod. You'll need this tool to hold the damping rod while you pull the bolt from the bottom of the fork.

 

The bolt in the bottom of the fork is has a socket head. I'm pretty sure it's 8mm but not certain it's not 10. Might want to grab those while you're out. Because of the recess the bolt is in you want them to be 3/8 drive or long, the 1/2" drive won't fit in there.

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The bolt works, but when I looked for one I couldn't find one. So.... Sears had a 17mm Hex Key. I cut about an inch off the end of it and the next door neighbor... 85 y.o. and needed something to do... welded it into an old junker socket I had laying around. Worked pretty good.

 

http://www.venturerider.org/progressive/The%20front%20suspension%20of%20my%2083VR%20was%20continually%20bottoming%20out%20due%20to%20some%20very%20old%20fork%20springs_files/progressive15.jpg

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The bolt works, but when I looked for one I couldn't find one. So.... Sears had a 17mm Hex Key. I cut about an inch off the end of it and the next door neighbor... 85 y.o. and needed something to do... welded it into an old junker socket I had laying around. Worked pretty good.

 

http://www.venturerider.org/progressive/The%20front%20suspension%20of%20my%2083VR%20was%20continually%20bottoming%20out%20due%20to%20some%20very%20old%20fork%20springs_files/progressive15.jpg

 

Great idea, Condor. I'll do the same if I can't find a 17 mm bolt.

 

Well, here's my progress so far. (You can see on the floor where the fork oil leaked.) I had other stuff to do, so I did not have time to drain the fork oil. That'll be first thing tomorrow, before going to get those necessary tools.

http://i2.photobucket.com/albums/y35/Tony1M/progress1.jpg

 

While cleaning the fork tubes, I could not help but notice that the driver's left outer fork tube rotates (a bit) noticeably harder than the right. Is this significant?

 

If I had all the parts I needed, I could probably get the whole thing back together tomorrow and maybe even go for a ride, but because I'll likely have to order parts, that's going to be impossible, especially if I decide to get the progressive springs.

 

BTW, what parts absolutely MUST be replaced so the fork doesn't leak? (Will Yamaha likely have these in stock?)

 

Which parts are also DESIRABLE to be replaced? (Will Yamaha likely have these in stock? Will parts from other years and models fit?)

 

And while I'm asking questions, am I going to have enough space between the floor and the fork tube so that I can slide the outer tube off the inner? I sure hope so!

 

Again, thanks very much for your help, folks.

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I have changed my fork seals on my 83 VR a couple of times. I got tired of buying seals at a Yamaha store (100 miles away) so I took an old seal to my Napa guy and he ordered seals for me at about $8.00 each. (Can't recall the number but it is a metric seal) I have never loosened the pinch bolts. I always remove the springs and after the front tire is off I use an impact and a hex socket and take the bottom retainng bolt out and slide the bottom 1/2 of the fork off.This probobly isn't the right way but it is considerably quicker.Frank

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Well, it was a real battle to break the fork cap free, but finally I did. I hope that the driver's right side is easier!

 

Here's a full length photo of the spring:

http://i2.photobucket.com/albums/y35/Tony1M/spring1.jpg

 

Here's the top:

http://i2.photobucket.com/albums/y35/Tony1M/springtop.jpg

 

Here's the bottom:

http://i2.photobucket.com/albums/y35/Tony1M/spring2.jpg

 

I don't think the photos do justice to the visual difference between the top and bottom of the spring.

 

I'm guessing it's a progressive spring. I'm anxious to hear if I'm wrong.

 

(BTW, there was indeed zero pressure in the fork. When I removed the drain screw, the oil just dribbled out. As I said before, even with zero pressure, as far as I can tell, the bike handles great.)

 

I'm now ready to remove the outer (lower) tube. Wish me luck.

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It's a progressive.... :thumbsup2:

 

The progressives usually have a piece of 1/2" PVC on top to preload the spring. Can't remember exactely how long, but around 5". I cut my preload in half and still use the CLASS. With the top cap off the oil should have drained fairly easily.

Edited by Condor
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Those look like stock springs to me. My Progressives from one end to the other continually have the coils going from tighter together to having more space in between the coils. I'm sure someone has a pic for you My bad I guess I should have looked at the pics with my glasses on :doh::256:

Edited by Pappa Bear
Blind as a Bat!!!!!!!!!!
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Condor,

Thanks! No need to spend money on new springs! (You know what that means.)

 

I have no spacer on top of the spring. Should I stick something in there when I reassemble?

 

BTW, the uncompressed length of the spring is 20-3/4". (Pappa, at the top of the spring there are 13 coils per 3". On the bottom there are 8 coils per 3".)

 

The nuts on the 1/2" threaded-rod tool are apparently too big. When I put the tool down into the tube, I hit a stop, but the tool spins freely. Should I grind down the faces of the nuts a little bit?

 

I can probably grip the outer fork tube with a strap-wrench and use our electric impact to remove the allen-head bolt. Is this OK?

 

Thanks for the help, guys.

 

Tony

Edited by Tony1M
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Condor,

Thanks! No need to spend money on new springs! (You know what that means.)

 

I have no spacer on top of the spring. Should I stick something in there when I reassemble?

 

 

Tony

 

There should be four washer/cups... 2 per side.. that will fit into the PVC for a preload, and keep the spring from chewing up the plastic. They're OEM. If there are none then it's time to put some in, and one of the reasons for bottoming out. I can see where the P.O. might have left them out as it's a PITA getting the top plug to thread back into the tube. He may have just given up. That's where that modified socket comes in handy. The relaxed length of the stock spring is 18" and the I'm running about 3"PVC preload. Some of the guys are running the whole 5" (aprox.), but I'm still using the CLASS air assist. The spring -is- a progressive. Much thicker coils than stock. IT also displaces more oil so when refilling the forks plan on using less oil to fill.

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There should be four washer/cups... 2 per side.. that will fit into the PVC for a preload, and keep the spring from chewing up the plastic. They're OEM. If there are none then it's time to put some in, and one of the reasons for bottoming out. I can see where the P.O. might have left them out as it's a PITA getting the top plug to thread back into the tube. He may have just given up. That's where that modified socket comes in handy. The relaxed length of the stock spring is 18" and the I'm running about 3"PVC preload. Some of the guys are running the whole 5" (aprox.), but I'm still using the CLASS air assist. The spring -is- a progressive. Much thicker coils than stock. IT also displaces more oil so when refilling the forks plan on using less oil to fill.

 

My springs are amost 3" longer than yours. Do I still need the pre-load? (BTW, as far as I can tell, our front suspension never bottomed out, even over some pretty deep potholes.)

 

I just broke a pneumatic 3/8" to 1/4" socket adapter trying to loosen that 10 mm hex bolt inside the bottom of the outer tube. The PO must have really put the loctite to that bolt. The strap wrench is incapable of holding the tube while using a simple lever. Can I re-install the fork brace in order to have that prevent the outer tube from turning as I attempt to loosen that hex bolt with a breaker bar?

 

Thanks again.

 

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