Fork Repair

[rmzaurora]

I've got a '90 VR and I noticed a while ago that the forks seemed to be weeping, so I got energetic this last weekend and following a couple of the older threads on here I was able to open up the top end and add fork oil, I'm hoping to just get her through the summer and then this winter I'm planning on an entire front end rebuild.... Well everything went well or so I thought but when I rode it to work yesterday, the forks have absolutely no give, the CLASS system is running on high and I can't seem to get the air out of the front end, is it possible when I put it back together I pinched off an air line? Or maybe I added to much fork oil? I'm just looking for suggestions, I know I'm going to have to tear it apart agian tonight and see I am just hoping that one of you guys had the same issue and maybe save me a lot of trouble and cursing at it tonight..

 

Thanks in advance for your help,

 

Bob

[Squidley]

Bob,

How much fork oil did you put in it and what weight did you use? I doubt you pinched a line unless you had the tubes out of the triple trees. A little more input on what procedures you followed and we'll be able to better give you some advise.

[rmzaurora]

I read a couple of the threads on here and I got some 10w from the local Yamaha dealer, as far as how much, the book said 400ml I put about 275-300ml in each side figuring that there was some left in there, since you say the air line probably isn't the issue then I'm guessing I need to drain out what I put in and start over... The only thing on the CLASS system is it's going nuts, when I push the "H" button for the front it takes like 10 seconds and it's at high, the compresser doesn't even run for a second or two, before I screwed with it, it took 30-45 seconds to air up... plus you could see the front end move up and down and now it doesn't move at all...

 

I should have taken it to a shop, I'm not a MC mechanic, cars I can work on but MC's are a whole different animal...

 

Thanks

[bkuhr]

Based on what I read with instructions from Progressive Springs, I figured I needed to put in oil until there was about 5" of air gap. I ended up overfilling-hard to tell, then stuck mity-vac hose 5" into fork and sucked all out down to 5" level.

[utadventure]

When I change out a set of spring in the '88 I had, they strongly emphasized the importance of matching the setup in each side to be equal for the front end to perform correctly.

 

Without draining the old oil and adding more to it without knowing how much was already in the forks you possibly have a)the forks out of balance with each other and b) potentially overfilled one or both with fluid. If overfilled the amount of air space for the compressor to fill would be reduced and the pressure would increase more rapidly.

 

My 2 cents worth: Put the bike on it's center stand, shift the weight to the back wheel - thus extending the forks, and open the top end of the forks. Then you can remove the fork oil drain screw and remove all of the fluid.

 

Replace the drain screw after they both stop draining and fill the forks as recommended in the service manual, paying attention that both sides receive the same amount.

 

Then reassemble the top end and test the air system again. You should see a much better result.

 

Good luck and happy riding!!

 

Dave

 

PS: If you have stock springs, use 13.8 US ounces of fluid in each fork, per the manual. If you have Progressive Springs, check their site for the correct amount of fork oil.

Edited June 9, 2010 by utadventure

[rmzaurora]

I'm headed home now to drain the forks and refill, I believe that they are the stock springs, I'm going to have the entire front end rebuilt this winter I'm just hoping I didn't screw it up to badly this past weekend. I'm betting on overfilled, I'll keep a close eye on how much each side gets tonight. Thanks again for all you guy's help and advice.

 

Ride Safe,

[stuckonstupid]

Rmz

 

I am in the process of trying to get my forks and seals contemplated on when exactly I'll consider getting started. ( I have the parts, just can't decide when) I bought new progressives and have decided that I already have pro's. That being said, you are welcome to my old ones and since I have already done this last year, BTW...don't use anything but OE Yamaha seals. I went the cheap ( Pyramid?) route last year and I'm doing it again this year, I can give you some cheap advice. Replace both seals and wipers, at least replace the top bushings, Progressives are great, replace all o-rings, use the right size phillips screwdriver (JIS #2, I think...I know it's jap sized) for the drain plug on each fork. I used Amsoil synthetic fork oil but I'm sure others are ok.

 

Call me if I can help

Ken

[saltcreep]

rmzaurora I ran into the same exact thing tonight, but I drained my forks 1st and then added 13.5 oz to each side... I knew mine were real low on oil because my front end is bouncy as hell and have been dripping on my tire. Not much at all came out, maybe not even 10oz between both of them.

 

They would not compress at all afterwards and my CLASS showed 40psi on the front ???

 

So I drained some, the psi on the front dropped , ran it around the drive and locked up the front brakes a couple of times.

It popped out the seal and dumped all of the fork oil on my front wheel and driveway...DOH!

 

So what I ran into I am guessing is not all the oil drained out, maybe some debris was blocking the drain hole? I don't know, I just thought I'd mention it so hopefully you don't pop that front seal like I just did.

 

I just parked it for now, too disgusted to mess with it at the moment.:headache:

[rmzaurora]

I really appreciate all the feedback from you guys, but when I got home Wednesday night I started to really inspect the front end before I started to take it totally apart again. What I found really sucked.. for lack of a better word.. The forks have compressed up into what I'm guessing is the bushings, and they were stuck. I called a buddy of mine and he said he had only seen this happen once or twice before on other bikes. So to make a long story short I ordered new Progressives for the front yesterday I went to the dealer last night and ordered new seals, bushing, and all the assorted parts needed to rebuild the entire front end. I put the bike on it's center stand and took off the front fender and gave the top of the tire a good whack from my rubber mallet and the front end dropped out of where it was stuck at and looks fine now... But I know better. So it's back to the drawing board, the shocks should be here Monday and I'll let you all know if replacing everything worked...

 

Thanks again for all your help,

 

Bob

[Squidley]

Let us know how it goes on the rebuild and if you get stuck, you know where were at

[tpalshadow]

I just tore mine apart too and was a little worried about what I saw. The right side is missing the metal spacer below the oil seal (#21 on the 89 part diagram) and the left side had none of the wavy washers in it!

 

I'm assuming this is part of the reason the right side was weeping oil. I guess it's going to take a little longer than expected to re-assemble as I will have to order some more parts! I'm hoping it will ride like a new machine when it is all said and done.

[jasonm.]

if it's weeping from the seal. You need a seal for sure. Also inspect the inner fork tube for pits and scratches. Either will make you seal fail in short order. Also you need to have the forks comressed and no springs in to use the 5" measure rule. The other way is to just do one side by removing the spring and being on the center stand measure 10.5 to 11" to the oil. I suspect you have too much oil.