Fork tube caps-- UPDATE

[sandy]

Decided to rebuild me forks today. When it came to removing the caps, nothing worked. I have a pneumatic impact gun which still didn't work. Heated with mapp gas and still no budge. Tomorrow a drill press and a milling machine will get involved. I've already looked at Pinwall forks.  Been a BAD day. Just venting. Ugggh!!

I drilled 2 holes on top of the cap. A friend and I used a 1/4" punch and a 5 lb hammer and took many whacks at it. Finally came off. Same technique got the other one off. Two new caps are $160 at my local shop. I could get them for less but he helps me many times. We have a good working friendship. On the right fork, the cap screws to the damper rod with a 14 ft/lb torque. I had to use a 2 ft cheater pipe to loosen it. I hate pro mechanics who think impact guns save time.

[Bighead]

First question is did you try to lossen them before you removed them fron the triplets tree? Always lossen the caps before taking forks off of bike. I loosened mine after being on and not touched for 17 yrs.

[sandy]

Yes; top pinch bolts loose and 130 PSI on the impact gun.

[The emperor has no clothes]

Yes; top pinch bolts loose and 130 PSI on the impact gun.

Damn ! I wish I could think of something you haven't tried yet. I got nothing. 

[Bighead]

Yes; top pinch bolts loose and 130 PSI on the impact gun.

Hmmmmm was able To Remove mine with a box end wrench.

[Forge]

Did mine with a short socket on a breaker bar while using a pipe as a cheater bar. One was pretty tight, but was no match for the 3’ cheater pipe.

[sandy]

FYI: I help friends with repairs and have rebuilt maybe 20 sets of forks in the last decade. Never had this problem before.

[Hook#3287]

Same happened to me while rebuilding a set for a buddy.

Had to use a chisel and ball peen

Some times that cap just don't want to come off.

I keep an extra one around now, but they don't give them away.

[da prez]

Tap on it with a hammer. Sometimes the shock will loosen them.     

                    da prez

[Chrisj CMA]

Did you try heat?  Heat guns do magic

[Tfrank59]

Decided to rebuild me forks today. When it came to removing the caps, nothing worked. I have a pneumatic impact gun which still didn't work. Heated with mapp gas and still no budge. Tomorrow a drill press and a milling machine will get involved. I've already looked at Pinwall forks.  Been a BAD day. Just venting. Ugggh!!

I feel your pain man sorry. Sometimes those things are just impossible you got aluminum screwed into steel and you don't actually know the right combination of heat, penetrant oil, impact or slow even torque that'll make it work. Hindsight is always 20/20. It sounds like the threads are galled and that's why I suppose you're going to end up machining out the plugs huh?  Let us know what you learn.

[Gryphon Rider]

Did you try heat?  Heat guns do magic

Decided to rebuild me forks today. When it came to removing the caps, nothing worked. I have a pneumatic impact gun which still didn't work. Heated with mapp gas and still no budge. Tomorrow a drill press and a milling machine will get involved. I've already looked at Pinwall forks.  Been a BAD day. Just venting. Ugggh!!

[h13man]

This is a problem using aluminum to aluminum thread contact being over torqued and/or corrosion added in. You're quite obviously at the point of no return but I suggest using anti seize on the new threads. BTW I feel the frustration from here.

[Bagger John - #3785]

There's an O ring on the top side of the fork caps which is designed to prevent water ingress. On all the "stuck" caps, was this compromised in any way? Was it replaced any time the forks have been apart?

[Tfrank59]

There's an O ring on the top side of the fork caps which is designed to prevent water ingress. On all the "stuck" caps, was this compromised in any way? Was it replaced any time the forks have been apart?

o-rings also keep out penetrating oil, so if they happen to have been compromised, a guy could spray some oil in there and wait and that could help free up things.  Happens all the time where I work when we're trying to get hydraulic cylinders apart.

[Paladin528]

There is no need for them to be that tight.  if the O-ring is in good shape you can just snug it up.  The upper pinch bolt will "lock" it in place.  I just removed mine and loosened the pinch bolt then a short combination wrench did the trick.  By the look of the fluid thats the first time they have been off in a VERY long time.

[Bagger John - #3785]

There is no need for them to be that tight.  if the O-ring is in good shape you can just snug it up.  The upper pinch bolt will "lock" it in place. 

Service manual states 14 ft/lbs for those caps.

All the ones I've taken apart for the first time since they left the factory were very easy to loosen with a 1/2"dr 6pt socket and an 18" breaker bar. When putting the fork tubes back on the bikes I merely snug the caps up, put the tubes in the trees and tighten the lower pinch bolts. Then, torque the caps to the listed value and torque the upper pinch bolts. Lastly, re-check torque of the lower pinch bolts.

[WintrSol]

My copy of the service manual says 25lb-ft for the caps; the 14lb-ft of for the damper lock nut under it. Not much, in either case.

[mrgeoff]

   I do believe that there is an anti seize made especially for aluminum to steel contact...I could be wrong but it would be something to check in to...!!!