Frozen Adjustable Fork Caps

[SEd27]

Does anyone have any tips on how to free up frozen late model adjustable fork caps?

I pulled the forks this past weekend to swap in a pair of Minton modded 77' dampers and for the life of me could not get the adjusters to budge past the lowest preload setting.

The bike sat out side for a good portion of its life, so the slotted tops show some signs of corrosion.

Currently, I have the cap bolts soaking in penetrating oil.

Any input would be much appreciated.

 

[angus67]

What kind of oil? Some work better than others. I like pb blaster. At this point, you've done all u can

 

[gggGary]

I have fought some really rusty ones and got them freed up, the "secret" is; they CAN be driven straight down. so you can get a drift on the head support the fork cap and drive the shaft down, when it moves a bit, lube, spray rust bust, drive back up, repeat as often as needed til it frees up. I think if you really want a full monty you can drive out the cross pin, then the adjuster will exit out the top of the cap.

 

[weekendrider]

Oil of whatever type, pb, diesel, transmission and acetone only lubricate the rust. Vinegar eats it.

 

[5twins]

Hmmmm really. Do you think that might work on a stuck motor? I've got one that seems to be hopelessly stuck. Those pistons seem fused to the cylinder walls. I've literally been soaking it for like 2 years with penetrating oil, lol.

 

[weekendrider]

For the six bucks it costs for a gallon of cheap vinegar. . . . . .
I've done two pairs of the adjustable fork caps. One with penetrating fluid which still required numerous back and forth poundings and wiping.
One by soaking in vinegar which still required some back and forth but it didn't feel as gritty and cleaned up quicker. Maybe it was happenstance.

 

[SEd27]

Thanks so much for the replies. I had them submerged in PB blaster.

Will try soaking in vinegar and gently pounding on the tops.

 

[SEd27]

So, I tried the vinegar soak for a few days and one of the adjusters came apart with very little effort. Its crazy how well the rust dissolves in straight white vinegar.

The other cap did not fare so well.... Managed to destroy the aluminum body, while attempting to pound the rod out (I even threaded the bolt into an old fork tube for support).

Does anyone had a spare fork bolt they want to get rid of?

 

[jamesgs4]

I have 1 spare, pay shipping and its yours.