Dump and run method of changing fork oil by Dave Moss

[katana]

Following on from my fork oil change, on the fazer forum this guy was mentioned.

Here is his video for non adjustable forks:


While here is the cartridge version


So after watching the videos what do you think?

What do you think of wait till the oil starts to drip, and that is clean enough?

What about greasing the greasing of the fork seals.

[wull]

I haven’t watched the video but I’m guessing you’re talking about fork stiction with regards to lubricating the oil and dust seal?

You said in your other post that it’s been 10 years so I’d do the full shebang, replace the seals etc and do it properly, no point doing a dump and run, lubing the seals for stiction just for a seal to shit itself in the near future then you have to go through the process again.

Here’s a video I made 4 years ago showing the difference between having fork stiction and not having it. It’s quite a difference.

[roadster]

One of the issues with fork behaviour is caused by alignment problems if the wheel spindle is not tightened in the correct sequence. Generally the nut side of the spindle should be tightened but the clamp on the right hand fork should only be snug not tight. The forks should then be vigorously bounced to achieve good alignment of ( usually) the right hand fork leg before the clamp is tightened to the correct torque. Different designs have other variations but the principle is the same. If the forks tubes are being re-installed then much the same principles need to be applied on tightening the triple clamps in the right sequence.

I have a couple of low capacity machines which do not have any ability to change the distance between the bottom fork eyes. There is no hope of avoiding over constraint on these!

[mangocrazy]

I note that the damping rod fork that Dave Moss did the dump and run procedure on had only 700 miles on it, but still had black residue in the oil. There would probably still be some residue left in the fork, but not enough to worry him apparently. With forks that had 10 years use on them the oil would be full of crap and draining them would still leave plenty of that crap behind. So I'd either strip the forks completely and clean them out, or flush the forks a couple of times with degreaser or petrol to get tthe last of the crap out, then leave to drain before re-filling with fresh oil.

But after 10 years with the same oil I'd personally be doing a full strip down to check on the state of the fork bushes and seals.

[katana]

I haven’t watched the video but I’m guessing you’re talking about fork stiction with regards to lubricating the oil and dust seal?

You said in your other post that it’s been 10 years so I’d do the full shebang, replace the seals etc and do it properly, no point doing a dump and run, lubing the seals for stiction just for a seal to shit itself in the near future then you have to go through the process again.

Here’s a video I made 4 years ago showing the difference between having fork stiction and not having it. It’s quite a difference.

Thank you for the video.

My rebuilt forks are fine, no stiction issues. Saw the videos and wondered if anyone else did this. So thought I'd ask here and see what other people thought. Do any other people lube the seals as it seems likea possible way to cause issues.

[katana]

I note that the damping rod fork that Dave Moss did the dump and run procedure on had only 700 miles on it, but still had black residue in the oil. There would probably still be some residue left in the fork, but not enough to worry him apparently. With forks that had 10 years use on them the oil would be full of crap and draining them would still leave plenty of that crap behind. So I'd either strip the forks completely and clean them out, or flush the forks a couple of times with degreaser or petrol to get tthe last of the crap out, then leave to drain before re-filling with fresh oil.

But after 10 years with the same oil I'd personally be doing a full strip down to check on the state of the fork bushes and seals.

Was interesting that the cartridge forks were only 700 miles on them and all the bits that came out. The idea of going till the dripping stars does intrigue me. I'd spray in some brake cleaner and maybe some pour in a little new oil to collect any debris left.

[dern]

Unless you know when the bushes were done then that's a bodge as far as I'm concerned. As soon as I saw all that metal come out I'd have stopped and ordered the bushes and done it properly.

I'm sure that he know what he was doing but the video doesn't explain what the motivation for doing the dump and run was. I've done it once on a track bike but the oil came out more or less clean and I was short of time.