Fork Oil Replacement Question

[smitty2600]

I'm about to replace the fork oil and looked at the service manual. Here's what it says.

"Oil replacement with installed fork. To have access to the upper plugs of the fork legs it is necessary to undo the four screws fixing the half handlebar plates; remove the half handlebars. Take off the rubber caps and unscrew the upper plugs. Undo drain screw at the base of each leg and drain out all oil, screw in again, fill up with the oil quantities prescribed, from the top of the legs and screw in again the upper plugs with o-rings."

My questions:

1. I took apart the half handle bars, but it appears that I really don't need to; I can remove the rubber caps with out removing them. Are there different handle bars on different Pasos?

2. Under the rubber caps there's a nut with a tire nipple on top of it. Is this what I'm supposed to remove? If so… after I put it back together do I have to put air in it? If so, how much pressure?

[Desmo_Demon]

1. I took apart the half handle bars, but it appears that I really don't need to; I can remove the rubber caps with out removing them. Are there different handle bars on different Pasos?

I believe that all handlebars are the same and interchangable.

2. Under the rubber caps there's a nut with a tire nipple on top of it. Is this what I'm supposed to remove? If so… after I put it back together do I have to put air in it? If so, how much pressure?

Yes, this is the tube cap that you must remove, which is why you need to remove the handlebar. Be careful, as it is a little under pressure from the spring. If you can raise the front wheel off of the ground in a way to unload the front suspension, it will be easier to remove and reinstall the cap, but it will still be pressurized (the cap can shoot up into the air if you aren't careful when you get to the last thread on the cap.....apply downward pressure to the cap, as you turn it, to prevent it from getting away from you).

I'm not too sure what the optimum pressure is for the forks, but I've heard 5-6 psi. I haven't gotten to that stage of my project, yet.

Here is a picture of the forks disassembled. You will see the cap that you need to remove in the top, right corner of the picture...

[Fraser]

smitty2600,

My understanding is that you do not have any pressure in the front forks. (After saying that I have tried 5 and 10 psi, with no real noticable difference). The air cap is so you can release any pressure accumulation.

Fraser.

[DaveM]

How much oil does each fork leg take ? and what grade is best to use.

Dave

[smitty2600]

How much oil does each fork leg take ? and what grade is best to use.

Dave

According to my user manual it takes A.T.F. DEXRON or equivalent (SAE 10) and it takes 350 cc or 11.8 US fluid ounces. With that being said I just used good automatic transmission fluid (if you buy one quart which is 32 ounces, it is more than enough to do both sides).

Thanks Desmo_Demon, I changed out the fluids last night. I was able to remove the top nut with a large crescent wrench. However trying to reassemble it was nearly impossible, I had to use a very large socket and socket wrench to keep constant pressure on the nut.

[Desmo_Demon]

However trying to reassemble it was nearly impossible, I had to use a very large socket and socket wrench to keep constant pressure on the nut.

I reassembled mine off of the bike and used a large socket on the cap to apply pressure while turning. I used the socket against the palm of my hand until I got it to catch a few threads, then I took the wrench to it. You may have different springs, which caused more issues with your reassembly. I think I read somewhere that there were several different springs available for these M1R forks.

I reassembled my forks using automatic tranny fluid, also, and used the measurement method mentioned in the Marzocchi rebuild manual (measured from the top of the tube when it is completely compressed into the slider).

[DaveM]

Thanks for the advice i will do the forks at the weekend.

Cheers
Dave

[smitty2600]

A few other things:

I did all the work using the center stand. First I released the pressure from the top (under the rubber caps) before I removed the bottom screws to drain the fluid. I didn't want the fluids spraying everywhere. However, there was very little pressure so this wouldn't have happened. After you remove the top nut the rest of the fluid will drain.

[Marinus]

I used 5W fork oil and measured down from the top as the fork with the damper takes a little more oil from memory. I also seem to remember my spring being under little or no pressure when resembeling. I took out a 25mm spacer that someone had put in there before me. My front end was to hard when I got the bike and was contributing to the bike pushing wide when exiting corners. I am 190cm and about 95kg. The bike is now a little soft but comfortable. It doesnt bottom out under hard breaking. The most important thing is to get the front and rear working together. If one end of the bike is out of sync with the other then not so funny things happen in corners like pushing wide or falling in.
Go to http://www.strappe.com/suspension.html. I found it very helpful. There are a couple of other sites on the subject that are really good too.
I have a few bits of road close buy that I know I can really hammer to feel how each adjustment effects the handling.

[smitty2600]

I used 5W fork oil and measured down from the top as the fork with the damper takes a little more oil from memory. I also seem to remember my spring being under little or no pressure when resembeling. I took out a 25mm spacer that someone had put in there before me. My front end was to hard when I got the bike and was contributing to the bike pushing wide when exiting corners. I am 190cm and about 95kg. The bike is now a little soft but comfortable. It doesnt bottom out under hard breaking. The most important thing is to get the front and rear working together. If one end of the bike is out of sync with the other then not so funny things happen in corners like pushing wide or falling in.
Go to http://www.strappe.com/suspension.html. I found it very helpful. There are a couple of other sites on the subject that are really good too.
I have a few bits of road close buy that I know I can really hammer to feel how each adjustment effects the handling.

I have those spacers also....those 25mm spacers were put in there by Ducati, you can see them in the picture above (it's the second one in...on the top right).

[Desmo_Demon]

After you remove the top nut the rest of the fluid will drain.

Sometimes you have to "pump" the fork by raising and lowering the wheel to get most of the oil out. I know with my Harley's forks, I can get another ounce of fluid out by pumping it (I change the fork oil in the HD every 10k miles....It's due, again, next week).

I have those spacers also....those 25mm spacers were put in there by Ducati, you can see them in the picture above (it's the second one in...on the top right).

That is correct. Both of my forks had that spacer in them. They are even listed in the Marzocchi repair manual....

http://www.bevelheaven.com/manuals/M1R/ ... age001.htm

[Marinus]

I have those spacers also....those 25mm spacers were put in there by Ducati, you can see them in the picture above (it's the second one in...on the top right).

They are there on the diagram. I don't know why I didn't see them before

I took them out because I didn't think I could get the forks to match the back suspension. The funny thing is I don't find the bike overly soft the way I have it set up. I ride my friends triumph Daytona and that is quite a bit harder then how I have the PASO at the moment but the roads we ride can be a little rough in places and I have never bottomed the bike out. Having said that, if the PASO had the breaks that the Daytona has then I'm sure the front would feel too soft under breaking.

I will have a play with it and firm it up again. Now that I'm really comfortable on the bike it will be fun to play with the set up again.