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vic28222

Fork Oil Flush And Change

I have a 99 VFR with 35K miles on it. The fork oil has never been changed and the seals are not leaking. I will have the fork tubes off while steering head bearings are being changed (I'm going to post a separate note on this) and would just like to clean out my forks and change the oil but have several questions:

1. I would rather not disassemble the forks. Can I get away with just dumping the old oil, putting in some sort of solvent, pump a few times, drain overnight and refill? If so, what solvents (kerosene, laquer thinner, etc.) can be safely be used to flush the forks?

2. I am making the assumption that if the fork seals are not leaking that there is no real reason to change them at this time. Is this a safe assumption? I have heard of people getting close to 100K on original fork seals on VFRs.

3. What is considered to be the best fork oil now for the stock 5th gen? Weight? (Stock Honda SS-8 is 10W)

3. I know that a huge # of the people on VFRD think that the stock forks suck, and perhaps they do, and that one should replace valves if not cartridges, springs, etc. but my forks are just fine for me as they are and I am taking the position of "If it ain't broke, don't fix it." I just want to clean them out and replenish the fork oil. I have looked though all the "how to" suspension posts trying to find simple guidance on how to do this with pics but have not come across one. Everything seems to include changing something. If any of you know where I can find a post with pics that simply discusses how to do the fork oil drain/flush/replenish process, please send me a link to it.

Thanks in advance for your help!

Vic

PS. If you want to send me a note directly, please write me at vic5491@yahoo.com

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I would like to do the same on my 99.

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Being that you have 35k on the bike, you really should take them apart and change the bushings after giving them a thorough cleaning.

The job is not very difficult, and if you add your location to your profile, you might even get a member to help you and guide you through it. Once you've seen it done and/or done it once yourself, it becomes easy.

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1.Can I get away with just dumping the old oil, putting in some sort of solvent, pump a few times, drain overnight and refill? If so, what solvents (kerosene, laquer thinner, etc.) can be safely be used to flush the forks?

Yes, you can, although it is better to do as SEB posted and give 'em a rebuild. I suppose kerosene can be used for flushing, not thinner!.

2. I am making the assumption that if the fork seals are not leaking that there is no real reason to change them at this time. Is this a safe assumption?

If yo decide to just flush the fork oil, yes.

3. What is considered to be the best fork oil now for the stock 5th gen? Weight? (Stock Honda SS-8 is 10W)

I would go with stock weight.

If any of you know where I can find a post with pics that simply discusses how to do the fork oil drain/flush/replenish process, please send me a link to it.

In the maintenance section there is the following page describing catridge service:

http://www.vfrdiscussion.com/forum/index.p...p;showarticle=9

But if you just want fresh fork oil an nothing else: remove forks, unscrew top caps, remove springs, keep forks upside down to drain oil, flush with new fork oil or kerosene, assemble fork in reverse order.

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I have done this a couple times just for new fluid. Drain the fluid. Pump the rod up and down until you hear the fluid is pumped out. I used brake cleaner the first time and pumped out the old fluid. I then put in new fluid and pumped the rod to make sure there is no brake cleaner left. New fluid does a decent job of flushing old fluid out. With the miles you are due to tear them apart. I bet the fluid is really contaiminated and you cant get it all out without disassembly.

Your bushings are probably worn and the seals are rather old.

But yes, you can do just what you desribed. Loosen the fork caps before you remove the forks.

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Purists would say you should disassemble the forks, change the bushings and possibly spend $$$ on new valves. Cheapskates like me still get major improvements with just flushing the tubes and filling them with the prescribed amount of fresh oil.

Oil level is quite important. You should check the actual level, not just pour in 325cc (or whatever the number in the service manual is).

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Kerosene is a much friendlier solution to use than thinner or brake clean. I have done it a number of times and my 99 has 55,000 miles on it.

I don't think you need a rebuild unless the seals are leaking and the forks are showing a defined lack of response.

If you choose to just flush them out, do it a number of times with the springs out, of course. You can put the cap on and invert them while pumping as well as pumping in the natural position. I usually drain, fill, and pump with three fresh fills of kerosene. Do not overfill the forks during this process.

Here is the most important part. Spend a lot of time pumping the kerosene out before refilling with oil. There are a lot of areas in there that kerosene hides and it takes a bit of pumping and time for it to drain all out. I actually leave them inverted overnight and get a good bit of kerosene out the next day.

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If your forks have never been serviced then you definately need to change the oil. I'd recommend flushing them out several times with the same kerosene solution then once again with fresh kerosene to see if they are truly clean. They are probably filthy. Check slider tubes for rust pitting. If you are considering new springs this is an excellent time to do that as well. Just had my forks done with Racetech GV and the inner and outer bushing showed little or no wear after 54K miles. I wouldn't replace them until you need to do seals or decide to upgrade the valves. I put 7.5W oil in mine.

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I too had the opinion that "if it ain't broke don't fix it" as it concerns fork seals. But the collective brains on VFRD convinced me to do it while the forks were out. It was a wise decision. Although my forks weren't leaking, the rubber on one of the seals was split and it was obvious that there wasn't much life left in it. I had fewer miles than you at the time. Fork seals are not too difficult to replace and the bushings are literally a piece of cake.

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If any of you know where I can find a post with pics that simply discusses how to do the fork oil drain/flush/replenish process, please send me a link to it.

Maybe a video helps in deciding if this is a task you want to do by yourself. This youtube channel/user has some motorcycle maintenace videos up on youtube, for intance on how to replace the head bearings. Of course he doesn't show you everything as he wants you to buy his DVD's. Still it gives some insight on what skills and tools are required.

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Thanks to all who have chimmed in on this topic and offered helpful guidance! I do appreciate it!

I posted two different notes a couple of days ago requesting help.... 1) This note about simply flushing and changing fork oil and 2) How to change out my own steering head bearings. I got a lot of help with both and will be doing the work myself as soon as I find a little time and my garage is warm enough to work in without shivering!

I still plan to simply flush and refill my forks at this point but now know that I can easily do so using kerosene to flush and how to do so. I'll likely use the OEM Honda SS-8 oil and set the level as prescribed for stock. As I said earlier, the forks have been just fine thus far and the seals are not leaking so I do not feel the need to change anything.

When I got a quotes on having both the forks and steering head bearings done both mechanics advised against changing steering head bearings to tapered bearings and both wanted to totally rebuild my forks with new bushings, seals, etc. The cost of both jobs with parts were going to be in the neighborhood of $500. By doing the work myself, and simply flushing and refilling my forks and going to tapered bearings in the steering head the total cost will be less than $100 including a couple of tools I will have to buy. Assuming it all goes well, I will have saved a bunch of money, learned something new and valuable and picked up a couple of new tools along the way. All in all, this sounds like a win-win all the way around.

Thanks again to all for your help!

Cheers,

Vic

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In the video in posting #10 the mechanic removes the allen bolt at the bottom of the forks and then removes all the internals. My question is can one clean then inside of the forks with kerosene without separating the two exterior parts of the forks? My guess is that you can???

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yes after the allen bolt is out you can pull the insides without pulling the tubes from the sliders.

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V4 Rosso posted a link to fork cartridge service. Due to linkrot, the page he links to has moved.

The new link is: http://www.vfrdiscussion.com/forum/index.php/topic/9-cartridge-fork-service/?hl=fork

The only thing I would do different from the linked writeup would be to loosen the top bolt FIRST, before loosening any of the other bolts. Don't take it off, just loosen it. This will prevent the need to risk scratching the fork while putting it in a vice.

With luck, I'll be changing my fork oil sometime in the next two weeks.

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Does anyone know the size of the drain bolt on the bottom of the forks on a 5th Gen? I want to buy the correct sized long reach hex/socket.

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Does anyone know the size of the drain bolt on the bottom of the forks on a 5th Gen? I want to buy the correct sized long reach hex/socket.

I think it is 6mm.
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Does anyone know the size of the drain bolt on the bottom of the forks on a 5th Gen? I want to buy the correct sized long reach hex/socket.

I think it is 6mm.

I'm pretty sure it is 6mm too

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Yes, 6mm. You need a long bit. Shorties won't reach.

Ciao,

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FYi, you don't have to do a total fork dissembly just to change the oil. just remove the cap and the spring dump oil and replace.

Meaning you don't have to touch the bottom bolt and separate the fork, but if going to separate the fork, then you want new seals going back in.

Wow I replied to a 6 year old thread, who dug this up.

Edited by spud786

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