I'm in the process of removing forks from an M85. I need to pull the tubes down out of the clamps but am not sure how to proceed.

Is the top of the tube tapered and fit into a taper in the top clamp? Where can you provide some force to get them moving down? (There is some corrosion.) Trying to twist the tube by hand does not work.

The right fork seems to function as normal. However, the left tube is stuck at a length maybe 2 " less than full extension. The lower fork tube will rotate on the upper but that side does not want to compress or extend. Any suggestions?

The cap pulls the tapers together. Make sure the bottom clamp is fully free, loosen the cap a bit, spray some penetrating stuff around, load the forks so there is a pull on the taper and then use some persuasion techniques (tap cap downwards/tap on OD of clamp/apply heating etc.

Another way is to let all the oil out, take the spring out, leave the cap off and use the slider like a slide hammer to shock the taper free.

The stuck side may have a rusty fork tube bore or maybe the fork tube is bent or maybe the slider has a dent. Maybe the fork leg is completely full of oil or water.

Yep. Slacken Bottom clamp, Slacken Fork cap by a fraction of a turn and sharp (Soft Faced) hammer blow square on to the Fork Cap.

Taper should let go fairly easily.

Wayne....

You guys are pretty smart. The forks popped loose but there was some water in the fork tube. I was able to get it moving fairly easily and dump the water. It seems to slide OK now. However, is there a recommended repair/ recover method? Should I disassemble and polish all surfaces..or maybe just flush a few time with oil and move on? Thanks,

Dan

Important things to do if there has been water in there

Remove all rust from all the steel bits - especially the whole way though the ID of the fork tubes. Pitting is not important but getting rid of any particles that might come loose in service is important. Remember that the springs can rub loose anything not part of the parent metal.

I have recovered a set of severely rusted (internally) forks from a 348 Cota by cleaning all traces of oil out of the tubes and then plugging one end and filling the with molasses and leaving for a few weeks. This dissolves the rust and leaves the steel alone. Similar molasses treatment was used for the other steel parts like damper rods and springs. I haven't used molasses on any aluminium parts and suspect it may damage them. I usually use a specialised aluminium corrosion treatment for those parts.

You should not need to polish anything except the outside of the sliders (for visual appeal). The sliding surfaces (ie damper piston to ID of fork tube and the anti-bottoming devices) do not need polishing.

After you get the bike rideable, use it for a few hours then change the fork oil to remove the fine particles generated by the running-in process.

The only remedy for pitting of the chromed surface of the tubes is to have them re (hard) chromed or to buy new tubes. This is commonly required on old bikes.

How does molasses eat rust? Isn't it sort of just sugar?

yes its a byproduct of sugar manufacture. I have no idea how it works but it is commonly used for cleaning up rusty steel for automotive restorations. Have a look on google if you really want to know how it works.