K 75 Fork Oil Change - unscrewing top cap

[BlueStreak]

How on earth is this done?! Is a special tool needed to hold that two-sided whatever while unscrewing with the 6mm hex bit?

Using an 17mm open ended spanner (Haynes) seemed obvious until I tried it. Channel Lock pliers are no good since they will chew up that soft brass colored metal in no time. I can only imagine what Vise Grips would do! Of course, I gambled and drained the oil from below before attempting the top cap.:banghead

[deilenberger]

Ah.. no manual?

The top cap doesn't unscrew. The bolt in the center of it DOES unscrew, and if you are just changing the oil - that's all you have to remove (a turkey baster makes a fine funnel to use with that hole..) You may have to hold the cap to keep it from turning, I always used a large adjustable (Crescent) wrench.

If you want to actually remove the cap - it's held in with a round wire spring that recesses into a groove cut in the inside wall of the fork tube. To remove the wire spring lock - you have to push the fork cap down. I found this easiest to do using an allen driver with a 3" extension in a ratchet wrench.. push down on the wrench at the same time as you turn the entire cap with it. It will move down, and you can use a tiny screwdriver or dental pick to get the spring lock out.

BIG CLUE - don't do this on the sidestand. The cap will come shooting out, take your eye out likely, followed by the spring. CENTERSTAND, and I actually like to jack the front of the bike (jack under engine sump) so the wheel is almost off the ground, removing as much spring pressure as I can. I keep a towel around the wrench - so it is soft if it attacks my eye on it's way out.

[Kayseventyfive]

Which K75 fork are we talking about here?

[Crow18]

Also be very careful with the drain plug bolts. They will strip if you look at them wrong (or over-tighten them).

[BlueStreak]

Yes, I am having trouble keeping the cap from turning. Maybe it is put together too tightly. I have the Haynes manual, which said to use a spanner. I tried that and a Crescent and a Channel Lock. The cap is recessed so the bite area of any of these wrenches upon the two-sided cap is very small. I feel like I need one of these, but in 17mm open end! http://www.alloy-artifacts.com/Photos/tools/chromexquality_db2425_wrench_offset_f_cropped_inse t2.jpg
You may have to hold the cap to keep it from turning, I always used a large adjustable (Crescent) wrench.


1993 K 75, sometimes referenced as a /2.
Which K75 fork are we talking about here?

[Crow18]

... The cap is recessed so the bite area of any of these wrenches upon the two-sided cap is very small...


1993 K 75, sometimes referenced as a /2.

I found I was able to get a better purchase after removing the windshield mounting brackets.

[Kayseventyfive]

I feel like I need one of these, but in 17mm open end! http://www.alloy-artifacts.com/Photos/tools/chromexquality_db2425_wrench_offset_f_cropped_inse t2.jpg





I went outside and looked at mine, and it looks like a close quarter crowfoot would do it. I think I will make one out of an extra open end wrench. Just cut the head to fit nicely into the recess and weld a bolt to it for a wrench to grab.

It might be possible, if you do not have a welder, to thread a hex head bolt into the cut-off wrench head and secure it with a lock nut and red Loctite to have something to grip. Owing to the tight clearance, the nut would have to be ground with a cutting wheel for clearance after assembly, being careful not to overheat the Loctite.

Or, you could bend two 90 degree angles in a steel bar and cut an opening in one end to fit. What is called a "cranked spanner" in Blighty.

.

[PHMarvin]

Hi, Bluestreak,
I do mine with a 17mm open end and a 6mm allen. If you added where you are, someone close might volunteer to visit and do it or, at the least, give immoral support! Were you near El Paso, I'd be there as soon as I could get there, with the tools I use.

After you get it done and it is time to close everything back up, remember, the torque reading on the allen bolt (where you add the fork oil) is NOT two grunts and a fart. And the drain bolts should be snug, not TIGHT. If you try to tighten them much, they will strip very easily. Good Luck!

[BlueStreak]

Hey, thanks to delienberger, kay, and Phil.

I managed to get the left side unscrewed with help from my son. I held the 17mm wrench on the cap while he loosened the screw with a 18" breaker bar; the brass cap is still in good shape. The right side still won't budge and is getting galled badly. I'm convinced there must be a special tool for this! Tomorrow, I'm off to my favorite store here in the San Diego area (Pat's Tools) to see if he has some oddball, right angle thing that might help. I don't see how a crowfoot would fit in there.

If all else fails, I might have to pull the battery, drain all fluids from the bike, lay it down and inject the 330 ml through the drain hole.

[98lee]

Go back to Don's post and follow directions for removing the cap. Put the cap in a vise held by the flats not the round part. You should then be able to remove the filler.


:dance:dance:dance

[deilenberger]

If all else fails, I might have to pull the battery, drain all fluids from the bike, lay it down and inject the 330 ml through the drain hole.Ah - this sounds like proof of the rule - always remove the fill plug BEFORE removing the drain plug. Most of us have eventually learned this by unpleasant experience.

[PHMarvin]

Hey, thanks to delienberger, kay, and Phil.

If all else fails, I might have to pull the battery, drain all fluids from the bike, lay it down and inject the 330 ml through the drain hole.

Hi, Bluestreak,
You're welcome! If you decide the above is necessary, first remove the recalcitrant fork. Yes, this entails removing wheel, calipers, fender, etc., but you'll be able to position the fork any way you need to refill with oil. You'll also be able to take it to the workbench and maybe be able to remove the filler plug.