1998 front fork caps stuck

[Zaos]

Goodmorning I was following Sean’s fork video but the top bolt caps with the air valve started rounding on me. I honestly have 0 idea what I did wrong considering I loosened the top clamp, used a 6 point 22mm impact socket yet it still rounded it. Now I was wondering what I should do next and if anyone sells these caps. New they are 150$ each which is fairly pricey.

 

[Fire-medic]

I forget what year bike you have, but this could be a good time to go from the 40 mm '85-'92 front end to a '93-''07 43 mm front end, if you're having to spend that kind of $.

I believe that since you say you have the schrader valve in the fork cap, you have a '93 or newer.

I think I'd remove the schrader valve, and empty the oil/no pressure in the downtube, and then use a heat source, and something like acetone and ATF (50/50), Kroil, or PB Blaster. Then see what kind of results you have. I don't recall having to use an impact socket on those caps. It sounds like someone did a 'way-past OEM spec torquing (17 ft/lb for the '85-'93 40 mm style) which should easily have been removed with hand tools and no impact driver. I suspect the '93-'07 cap bolt torque value is similar, look in the front of the service manual for the info, to confirm the torque for the 43 mm downtubes and their cap bolt torque spec.


https://ia800204.us.archive.org/14/...ice-manual/yamahavmaxvmx12-service-manual.pdf

Ron Ayres Yamaha
Bolt, Cap

3LR-23111-00-00

Retail Price: $149.99

Your Price: $136.35

https://www.ronayers.com/oemparts/a/yam/50045c14f8700209bc794304/front-fork (see #15 & 35)

OK, I found the '93-'07 spec for the cap bolt. As I suspected, the torque value for the cap bolt is the same for all years: 17 ft/lb.

 

[Zaos]

I forget what year bike you have, but this could be a good time to go from the 40 mm '85-'92 front end to a '93-''07 43 mm front end, if you're having to spend that kind of $.

I think I'd remove the schrader valve, and empty the oil/no pressure in the downtube, and then use a heat source, and something like acetone and ATF (50/50), Kroil, or PB Blaster.

It’s a 98 so I already have the upgraded forks. I used PB blaster before I impacted aswell. No idea what the issue is here. There’s still some grip with the sockets but it’s soon to round completely. I’m assuming I could use an extractor set but I really want to confirm I can find replacements for these caps.

 

[Fire-medic]

Contact Sean Morley [email protected]

or CaptainKyle [email protected]

as they are the used parts go-to guys here.

You might try inserting a bolt the same thread as the schrader valve, and a nut of the same thread, thread the nut onto the bolt, run the bolt fully-through the cap & then use the nut to run-down to lock the cap bolt to the machine screw in the schrader valve. Then try to back the cap bolt out.

Given your unfortunate problem it stands to reason that the last person to tighten the cap bolt, cross-threaded it, making it difficult to remove, as you've discovered.

A question: is it just one side, or both?

 

[MaxMidnight]

As Mr Medic says you shouldn't need much force to undo them. Are you sure you had the impact wrench set to undo and not tighten?
If the hex is completely goosed then a pair of stillsons (pipe wrench) may be the best option?
Then see if anyone has spare caps.

 

[Zaos]

Contact Sean Morley [email protected]

or CaptainKyle [email protected]

as they are the used parts go-to guys here.

You might try inserting a bolt the same thread as the schrader valve, and a nut of the same thread, thread the nut onto the bolt, run the bolt fully-through the cap & then use the nut to run-down to lock the cap bolt to the machine screw in the schrader valve. Then try to back the cap bolt out.

Given your unfortunate problem it stands to reason that the last person to tighten the cap bolt, cross-threaded it, making it difficult to remove, as you've discovered.

A question: is it just one side, or both?

Both sides.

 

[Zaos]

As Mr Medic says you shouldn't need much force to undo them. Are you sure you had the impact wrench set to undo and not tighten?
If the hex is completely goosed then a pair of stillsons (pipe wrench) may be the best option?
Then see if anyone has spare caps.

Yea I was able to get one off, still working on the other. I am sure it was set to undo. Ive asked around and no one seems to have one.