Ducati Monster Forum

Moto Board => Tech => Topic started by: desmodoktor on January 08, 2013, 02:51:34 PM

Title: Changing the Fork oil.
Post by: desmodoktor on January 08, 2013, 02:51:34 PM
hello,
thinking on changing the fork fluid on my 02 m750. any tips or advice?
is it a simple drain refill process? (proper amount)
is there anything i should pay more attention? never done it before. thank you .  [Dolph]
Title: Re: Changing the Fork oil.
Post by: He Man on January 08, 2013, 03:11:19 PM
I just did my fork oil, litterally like 15 mins ago. well i did the whole 9 yards, took out all the valves cleaned them and threw in new seals to boot.

There are a few tools involved.


http://kuixihe.com/node/1 (http://kuixihe.com/node/1)
Title: Re: Changing the Fork oil.
Post by: desmodoktor on January 08, 2013, 03:32:22 PM
Quote from: He Man on January 08, 2013, 03:11:19 PM
I just did my fork oil, litterally like 15 mins ago. well i did the whole 9 yards, took out all the valves cleaned them and threw in new seals to boot.

There are a few tools involved.


http://kuixihe.com/node/1 (http://kuixihe.com/node/1)

wow thats great what you did there! THANK YOU!  [thumbsup]
Title: Re: Changing the Fork oil.
Post by: dlearl476 on January 08, 2013, 06:21:30 PM
Quote from: He Man on January 08, 2013, 03:11:19 PM
I just did my fork oil, litterally like 15 mins ago. well i did the whole 9 yards, took out all the valves cleaned them and threw in new seals to boot.

There are a few tools involved.


http://kuixihe.com/node/1 (http://kuixihe.com/node/1)

Man, that's fantastic. Best Tech write up EVAR!  [bow_down]
Title: Re: Changing the Fork oil.
Post by: Slide Panda on January 09, 2013, 05:13:54 AM
Couple things to note when it comes to putting it all back in

1 He Mans bushings are knackered and need to be replaced
2. While you have things apart, it's a good time to polish the slider tubes. It'll improve their function
3. If you're not replacing the fork seals, I recommend you leave them on the sider. Saves you the risk of cutting them during removal. A cut may not be evident until you get the fork reassembled and oiled - which sucks, trust me.

Title: Re: Changing the Fork oil.
Post by: desmodoktor on January 09, 2013, 06:41:22 AM
Quote from: Slide Panda on January 09, 2013, 05:13:54 AM
Couple things to note when it comes to putting it all back in

1 He Mans bushings are knackered and need to be replaced
2. While you have things apart, it's a good time to polish the slider tubes. It'll improve their function
3. If you're not replacing the fork seals, I recommend you leave them on the sider. Saves you the risk of cutting them during removal. A cut may not be evident until you get the fork reassembled and oiled - which sucks, trust me.



Ok. Since the fork was never serviced on my 750 Idk what I'm going to see when I pull everything out . What parts in there wear out and are considered part of the service . I want to know so I order them . What type of fork oil are you guys using? I use MOTUL products for everything . I'm very happy with it. By the way , I have no leaks and the suspensions seems to work fine . I just want to change the fluid since the bike is 11 yrs old 10k miles .
Title: Re: Changing the Fork oil.
Post by: Slide Panda on January 09, 2013, 07:46:50 AM
Well - everything wears out... but the highest wear items will be the seals and bushings. Parts list will be

1. Inner Bushing, 1 per fork leg
2. Outer Bushing, 1 per fork leg
3. Oil seal, 1 per fork leg
4. dust/wiper seal, 1 per fork leg
5. Oil

Other stuff -
seal lube, a light coating just makes life easier during install
Seal driver, should be a 43mm
Damping rod bleeder tool - not strictly necessary but will save you a lot of mess and hassles.
If you like your tools - a no mar cap wrench http://www.motomfg.com/category_s/47.htm (http://www.motomfg.com/category_s/47.htm)

Other stuff like the valve shims do wear over time - but not to a point where you'd need to worry.

When you pull things apart have a good look inside for signs of gunk that would foul the porting.

Oh and be ready for a stink bomb. Old fork oil can get very very ripe smelling
Title: Re: Changing the Fork oil.
Post by: cmejia1978 on February 08, 2013, 10:49:51 AM
Help!!!! need to re-assemble the fork and for that there is a special tool, any ideas on how to doo it without it??¿ a friend of mine pointed out 2 screw drivers, a lot of patience and a firm grip, any ideas?¿ I have non adjustable forks, the part that I am trying to re-build is the fork seal, the 2 metal things that are before it with the metal seal kind a like... I will post the picture thank you!
Title: Re: Changing the Fork oil.
Post by: He Man on February 08, 2013, 11:08:50 AM
^ what.
Title: Re: Changing the Fork oil.
Post by: Slide Panda on February 08, 2013, 12:15:36 PM
If you've gotten it apart to the point you've removed the seals - you needed a spring compresser of some sort. Also, you need a seal drivers to seat the oil seal.

So:
Fork spring compresser
Fork seal driver - probably 43mm but you should confirm for your forks
Title: Re: Changing the Fork oil.
Post by: cmejia1978 on February 08, 2013, 12:25:36 PM
Yes indeed the spring does not bother me at all, but the fork driver, is there any way to do it without it?¿  [bow_down]
Title: Re: Changing the Fork oil.
Post by: Slide Panda on February 08, 2013, 12:40:32 PM
You might be able to make one out of some PVC. But you need something that will ensure the seal will be all the way in, even AND (big and) will not damage the easy to damage wipers on the seal. IF you nick or mangle that, you'll probably get a oil leak immediately. It'll be a small one, but will leak
Title: Re: Changing the Fork oil.
Post by: cmejia1978 on February 08, 2013, 12:49:29 PM
holy shit I better start taking the forks into my car and pulling to my friends workshop...  [coffee]
Title: Re: Changing the Fork oil.
Post by: Dellikose on February 08, 2013, 02:00:48 PM
What's the standard fork oil weight? I've seen a couple different answers, but the most common answer has been 7.5wt.

Do all models use the same weight? I have a '99 M900 with the adjustable Showas (I believe).
Title: Re: Changing the Fork oil.
Post by: He Man on February 08, 2013, 06:36:43 PM
you can make the fork seal drivers out of PVC and a propane torch to soften it and then cap them around the fork to mold it before it cools down.
Title: Re: Changing the Fork oil.
Post by: JoeB on February 20, 2013, 04:43:17 AM
Here are some pics of fork and damper rebuild (https://www.flickr.com/photos/zipzamzerpople/sets/72157632806676633/show/)
Title: Re: Changing the Fork oil.
Post by: nickshelby500kr on February 20, 2013, 06:14:19 AM
Quote from: JoeB on February 20, 2013, 04:43:17 AM
Here are some pics of fork and damper rebuild (https://www.flickr.com/photos/zipzamzerpople/sets/72157632806676633/show/)

just out of curiosity, how much did all of that run you?
Title: Re: Changing the Fork oil.
Post by: ajw85 on February 20, 2013, 06:21:23 AM
Quote from: JoeB on February 20, 2013, 04:43:17 AM
Here are some pics of fork and damper rebuild (https://www.flickr.com/photos/zipzamzerpople/sets/72157632806676633/show/)

Race-tech gold valves?
Which kind did you end up going with?
How do you like them?
Title: Re: Changing the Fork oil.
Post by: JoeB on February 20, 2013, 03:28:10 PM
I had Terry Hay (sydney) do the forks and rear damper.

Both are completely rebuilt.  The rear sachs unit has a rebound separation valve installed, and a revised shim stack as well as the uprated Eibach spring.

The front forks have a modified racetech valve and shim stack, and a few other secrets he has up his sleeve.

The results are a completely settled bike with more usable grip than ever, excellent communication from the suspension and it all cost less than a new rear damper (which was the direction I was headed until I spoke to Terry about the problems I was having with the tyres)