Fork cap removal...grr

83 Kz750 h3 Ltd with air assist. I have tried using an m8 1.0 bolt threaded into the valve and a breaker bar, heating it, penetrates, everything short of c4 and I cannot get the cap off.... ANY suggestions would be appreciated. I actually bent the bolt trying to remove this stubborn cap, and its design limits my choices on removal. Thanks everyone.

Be sure to loosen the top triple tree clamp bolt first. Ed

Yes, top of tree is loose as can be. Even loosened lower clamps and slid it up a few inches before retightening the lower.

Application of heat may actually be tightening the joint.

If the cap is aluminum and screwed into a steel tube, heat will expand the cap more than the tube, thereby tightening the grip.

In such case, it would be better to freeze the joint immediately before attempting to unscrew the cap. This may be done by applying dry ice to the cap immediately before attempting to unscrew it.

Good Fortune!

I haven't tried the dry ice. I'll give that a shot. Thank you!

Witchwerx:

Are you changing fork oil?

If so would you take some photos and document the process of disassembly/reassembly of the front suspension?

I have an 83 F1 that has 30 year-old oil in the forks.

Gary

upncummr wrote: .....
I have an 83 F1 that has 30 year-old oil in the forks.

The 750-F1 has different forks than the Ltd H models. Each F1 fork cap (spring seat) has a circlip. Also, the F1 has a cross-over tube assembly which balances the air pressure between the forks. The Ltd H models don't have that. F1 manual: search eebbaayy for KZ750 shaft manual.

Witchwerx wrote: 83 Kz750 h3 Ltd with air assist..

Is the bike an 83 750-H4 or an 82 750-H3?
Not sure if it matters, but the H4 forks are a little different than the H3 --- they have different fork caps (spring seats).

My forks are similar to the 750-H3. I had a spare triple tree which I used as a clamping device on a work table. I heated the tubes & used a crescent wrench to remove the caps. I think I smacked the end of the wrench handle with a mallet or sledge hammer.

upncummr wrote: ...Are you changing fork oil?
If so would you take some photos and document the process of disassembly/reassembly of the front suspension?
I have an 83 F1 that has 30 year-old oil in the forks.
Gary

Should be able to change the fork oil as a routine maintenance item without disassembling the forks,

Good Fortune!

The next time, yes. But 30-yr old fork oil is going to be yucky & what doesn't come out will probably contaminate the new oil. I would take 'em apart & give the innards a good cleaning w solvent. And I would go ahead & replace the seals. Maybe the fork gaiters too (?).

upncummr wrote: Witchwerx:

Are you changing fork oil?

If so would you take some photos and document the process of disassembly/reassembly of the front suspension?

I have an 83 F1 that has 30 year-old oil in the forks.

Gary

I used a small bearing puller to depress the top caps to remove the circlips. Leave the tubes in the triple and hook the puller jaws to the bottom of the clamp, when you thread in the ram, it will easily depress the top cap and hold it for you. Also, you can just thread the ram out and slowly relieve the spring pressure and vice versa.

Stupid question but I seem to remember some of those bikes with air forks having the tops held in with a snap ring instead of screwing in like regular forks,Do you have a picture of the tops of the forks?

I tried the dry ice method with no success. It's stuck on there tight. The base of the cap almost appears to be brass, which I found odd. Before I go at it with a monkey or channel wrench I'm posting a picture of the offending cap. The size again for the valve uses an M8 1.0 thread. At this point the bike may just have to bear the scars of the wrench. Any further ideas would be appreciated. If I get the cap off, I will write up a DETAILED fork seal replacement guide for everyone as thanks.