fork question

[leslo]

I've got an 81 GS750E and I think I need to replace the fork oil. As usual my clymer manual is of little help in this area unless I want to disassemble the entire fork assembly.
Can I put the oil in the air valve port at the top of the trees or do I really have to take apart the entire thing?
Also is there a set pressure I need to put on these air valves in psi?
Thanks guys,
Les

[Dink]

No there is no set pressure , in fact it is far better to set your preload with washers and forget air altogether.
if you look at the bottom of the fork leg above the axle there should be a small screw, this will drain the fork oil, you do need to at least take the fork tops off , you cant put oil in through the air valve, it is also a good idea to flush the fork leg out with kerosene before putting fresh oil in, also it is easier to do all this with the legs removed from the bike.
Dink

[Mr. Jiggles]

Careful taking those caps off - they can sometimes pop out pretty violently. Before removing, be sure to bleed any air pressure in the forks and remove as much preload as possible.

Good luck.

Jeff

[KGB]

Careful taking those caps off - they can sometimes pop out pretty violently. Before removing, be sure to bleed any air pressure in the forks and remove as much preload as possible.

Good luck.

Jeff

And there is a spring behind them. Be prepared for a launch from that spring once released.

[Anonymous]

I'm with Dink. Take the forks out of the triple tree, remove the top and springs, drain and flush, replace with fork oil to the recommended height, then replace the springs/ top and remount. Not hard to do and the bike will ride better.

[Hotblack]

I did the forks on my 550 (no air valve or DU rings) last year and remember it being a breeze. I put the bike up on the center stand and raised the front wheel up off the ground. Ummmm this is all coming back to me now.... I removed the front wheel. After that I drained the fork oil into a pan, then removed the handlebars (just lay them on a rag on the tank, don't bother disconnecting anything). From there I worked on one fork at a time, first removing the fork cap with a socket which enabled me to maintain even downwards pressure on the spring, I had no problem effecting a smooth release. If you do this with the fork still in the tree you can use two hands on the socket and none on the fork tube. Next I took the forks off for a thorough flushing, but you don't have to if you really don't want to, as long as you measure the fork oil volume as you put it in (the baby bottle method) instead of measuring the oil level (the oil suction gun method). It's not hard to take the forks out and put them back in though, I'd recommend just doing it. I did one fork at a time, always a wise strategy when working on two or more of something like this. This is also a good time to check you fork seals, and replace the dust boots if they're cracked. Mine were, and I'm fortunate that I got in and cleaned out the corrosion around the retaining clips before it got to the sealing area, they're still tight and strong. I also had two brass washers on hand for the little drains, just in case, but they were unneeded. I re used the old ones, and no leaks. Good luck! Oh, putting the springs back in isn't too bad with the socket method either, as long as the forks are in the tree. I don't know if your air valve will interfere with a socket, or if it's removable or what.