750 Paso fork MOT issues

[Graemer57]

Just been told that, to get through MOT, need to replace fork seals. My local friendly (Honda) mechanic doesnt want to take on the job because he is a bit worried about the possible complexity of marzocchi forks. How straightforward a job is it in reality? Am pretty competent mechanic though time poor but would like to hear from anyone with experience. Is there a thread covering this job, cant seem to find one?

Graeme

[paso750]

Graeme,

it`s fairly easy and in the downloads you find the M1R service manual.
https://app.box.com/s/auo3ckdjv0qirxdzo ... 24487115/1
All you do in short is remove fork, drain oil, remove bottom bolt and with a jolt pull the stanchion tube from the fork leg. Remove the dust seal, washer and stop ring. Then carefully drive a screw into the oil seal and warm up the outer part of the fork leg around the oil seal. Then with some pliers pull out the screw and seal. That`s a better method than levering the oil seal out as you can break away a part of the forks sidewall.
Clean the stanchion tube, oil it and the new oil seal a little and carefully pull the seal over the tube. Insert the tube in the leg, screw the bottom bolt back in, push the seal down and drive it down with a PVC tube or something with a matching diameter.
I`ll skip all the rest as that`s in the manual. Just beware to fill in the oil when the stanchion tube is fully pushed down the fork leg and when removing the top cap of the fork hold it with one hand while loosening it as below it is a preload tube and the fork spring which are under tension.
It can be a messy job so rubber gloves come handy.

Here`re the oil seals: http://www.ebay.co.uk/sch/i.html?_trksi ... +&_sacat=0
For the dust seals you`ll probably have to check your local Duc dealer. (#000048396)

G.

[Graemer57]

thank you for such a great reply!

Graeme

[lane1feathers]

G'day Graeme,
Fork oil seals and oil change is no biggie. I'm surprised a m/cycle mechanic won't do it.
I just did it myself and have never done it before so you should be fine.
Check out 3rd page of 'The story so far' in the 906 forum. Forks are the same.
I started by removing the brakes, then speedo cable, then wheel, then mudguard. You will need to support the bike from underneath at front of engine as its front heavy. I then placed a drip tray under forks and removed the drain plug at the rear of the fork leg just up from the bottom. Then I removed the rubber caps at the top of the forks and unscrewed the nut underneath. This removes the air valve and now you will have a steady flow of shitty oil coming out the bottom.
Now you need to go into your toolkit and grab the appropriate sized Allen key and coming up from the bottom undo the Allen bolt. You will need to use the long end to reach. For purchase use a ring spanner as it will be tight. It's easiest to get this bolt undone while forks are on the bike, still in the triple clamps and still under pressure of the internal spring. There will also be less chance of damage to stanchion tube than if using a vice. The rest of the oil and the gunge will now come out.
You are now free to remove the slider (fork leg) from the tube (stanchion tube). To do this you need to yank down on the slider (as if its a slide hammer) and it will come off the end. It may take 2 or 3 goes coz you'll be afraid of damaging the base on the concrete
Then you can remove the dust seals then retaining clips and oil seals as Gerhard suggests. It would also pay to flush with metho at this point to remove any grime from inside coz if you don't, you will end up with stuffed seals again.
I then undid bolts of triple clamp and slid the tubes down so top of tube is free of top clamp then tightened bottom clamp (to hold steady) while cracking the top nut that had the valve in it. This prevents damage from a vice. You can also do this step while tube still in both triple tree clamps, but you have to remove clip-on (my bolts were rounded so I couldn't) Now you can unscrew the top cap but be careful as the spring inside will want to pop it out when it gets to the end of its thread. Now you can remove the tube from triple clamp.
Place on bench and remove spacer, spring and the rest of the guts making sure to keep in order so you know how it goes back in . Clean inside tube with metho. LET THEM DRY. Then reassemble. I started by replacing the guts in the tubes then put the tubes in the sliders. Now slide the oil seal down from the top and into the slider. Use some PVC tubing as a slide hammer to push the seals home. If you use a screw driver you will damage the seal (as it is metal under the rubber and once it's out of shape, it stays that way and you need a new seal) Replace retaining clips then slide the dust covers over the top and down into place.
Replace bolt in bottom, and drain screws.
Now you have to replace the oil. For this the tube must be pushed all the way home into the slider. The cap, spacer and spring must be removed to do this. I then poured in the oil filling it to roughly 100mm from the top. I then inserted my home made oil sucker (see the thread I told you about) and sucked out unwanted oil. 180mm from top perfect. Then pull tube up to full extension and replace spring, spacer and cap. To get cap tight you will need to put fork in triple clamp. Continue with re assembly. Don't fill with air, valves are for pressure release only

[paso750]

That`s an interesting way to do it. I usually remove the handelbars to loosen the top cap w/o removing it.
Then I remove the fork from the bike, remove the cap, preload tube and spring and spill out the oil while moving the stanchion tube in and out a few times. (I don`t open the bottom drain screws unless only an oil change is done and the fork remains on the bike.)
After the bottom bolt is out I put an old towel on the vice and hold the fork tube by the caliper mounts to pull out the stanchion tube.

For assembly after replacing the seals and filling up the oil I screw on the top cap by hand put the fork back on the bike and after tightening the triple clamps I remove the cap again to insert the cleaned spring and preload tube. I find it easier to press down and screw on the cap when the fork is on the bike.

I have a front paddock stand like this which is as great help (also for storage, combined with a rear stand)
http://www.ebay.co.uk/itm/BIKETEK-UNIVE ... 5d408f215a

[lane1feathers]

That`s an interesting way to do it.

G.,.......everything I do is interesting

also some people don't have a bench in their garage let alone a vice so this gives an alternative.
Worked for me

[paso750]

then you have to ask the wife, friend or neighbour to hold the forkleg very tight while you yank the stanchion tube out
(what did you use to hold the bike up when the fork was out ?)

[lane1feathers]

I used my home made paddock stand
I made it when I did the strip down last year

You can clearly see it in this pic.

[higgy]

old plastic milk crates rule if you can find them

[Graemer57]

do they have to be made out of old plastic or does new plastic work just as well? :-)