Topic: Seized fork tube

[McBain]

I am currently in the process of tidying up my front forks. I had drained the oil out of one and was working it back and forward when it seized up, now I can't move it any way, forward, backward, twist it. It is stuck solid, any ideas for freeing it up? I've tried lubing it up and hitting it down with a soft hammer, tried twisting it in a visa to no avail.

[ekpent]

Just a guess but if you pushed the fork bottom all the way up too far the fork seals may be stuck on a rusty portion of the upper fork tube hidden under a fork gaiter.
  As Cal mentioned though more info needed to clarify.

[McBain]

It's a 750 k2, when it seized the damper rod bolt and spring were in, the seal had been removed, the spring and the dampener are now out. The only thing I can think of doing now is putting the fork housing in the vice and twisting the fork tube with a set of stilsons. I'm a bit hesitant to do this

[edwardmorris]

Early or late K2? Fork lowers were different. Try using some heat before forcing it in the vice.

[McBain]

The strange thing is it was working freely until I drained the oil, it had a two piece seal fitted and I had dramas getting the lower half of the seal out so it's possible I damaged the fork housing or tube (nothing visible).

[McBain]

So no harm to be done by heating the housing?

[McBain]

Well I managed to separate the tube from the housing using  a combination of heat and a set of stilsons, I taped the tube up to prevent damage from the stilsons. Found the tube has a big gouge in it so I will need to clean that up now.

[Stev-o]

What caused the gouge? That may be your issue.

[McBain]

Yeah there was a small piece of the housing floating around in there. I didn't have a hone to suit that small so I made one with a long drill bit with a rag wrapped around it with 1500 wet and dry taped around the rag. Worked a treat!

[McBain]

Forks came up a treat

[hotdog]

I'd be checking if your stanchion is bent....the cause in the 1st place

[PeWe]

+1 something bent....
Better to replace fork tubes now when it's apart instead of realise it later when driving the bike that must have bad handling or stucked fork on the road.
I have never had that kind of problem with my fork. CB750 K6-76

[754]

Next time put the fork back in the trees, and bolt axle in the bottom to. Try to loosen..no scarring..
 Fork tubes are self checking. Put one against the other,  turn 90 degrees a few times..like to see if there is a gap.. ..repeat. With the other..any bend will be readily apparent.

[BobbyR]

Find a flat surface and roll the tube over it back and forth. If it is bent you will know right away.

[McBain]

I rolled the fork tube on a flat surface and checked against a straight edge before reassembling, all checked ok. I have filled with oil now and they feel fine.

[BobbyR]

Good show!  Very simple test wasn't it