Commando forks maintenance...

I had bought a pair of new Honda #91255-KBH-003 fork seals almost two years ago to replace the 20+ year old originals.
Finally got around to installing them this week with the improved Spring weather in the Midwest US.

Man, it's a big job to get the fork legs off and disassembled. Even though I had changed fork oil several times over the years, there sure was a lot of sludge and solids in the bottom of the sliders. And rust on the top of the springs and rods.
But the top and bottom bushings and tubes were OK.
I have a 1-5/16" socket that is handy to remove the top tube nuts without risking the tach and speedometer.

I had to make some swabbing rods to get the crud cleaned out of the sliders and clean the area where the red fiber washer sits in the bottom.

In all I put about 10 hours into the job, including digging out the tools, cleaning, and replacing the front fender studs with socket screws.
The Honda seals need to have the outside diameter reduced just a bit to fit nicely.

I used 5.5 ounces of Maxima brand 15 fork oil in each leg. Since this oil is clear I included an ounce of red ATF oil for potential leak identification.

After all this work I wonder how effective is just changing fork oil through the drain screw. The internal components can build up a sludge layer that
won't be removed through that hole.

Satisfying work for an old guy like me, but I wonder what a shop mechanic hourly rate for the job would be?

Yeah man Bob its a dreaded task for me too and nothing to add but a nod on trying to keep ahead of a fully fettered Commmando. Mainly thanking ya for reminding me about the rust above fluid levels that I've had get so thick durring storage it took a hard bounce to compress fork some and then stayed down, ugh. So decided to paint upper parts next time inside. Always a next time, we hope eh. Hope all the electrics remain functional afterwards.

Bob Z. said:

After all this work I wonder how effective is just changing fork oil through the drain screw.

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I take the old girl out for a brisk ride, then pull the plugs promptly upon arriving back at the shop. While these are draining, the engine and transmission oil get dropped. And this year, at the two-year anniversary, the front brake fluid was flushed. Yes, it takes a lot of drain pans...
It's a bit disconcerting the amount of black streamers that exit into the drain pan, but it bolsters my confidence that most of the crud is in suspension, and going out with the oil. I won't know for sure until the forks come apart for seal replacement. I hope that'll be awhile...

Nathan

Re-filling the forks with oil with the long springs in place can be messy and slow.
Did you use any special home-made deal to help trickle in the oil?

Also, draining through the small screw hole can require pumping the forks up and down several times.
Then you get some good velocity squirts that a drain pan can't catch.

By the way, the old seals still had the remnants of the thin paper washer located between the bushing and seal.

I fill factory forks via a cattle syringe with syringe so fluid dribbles-adheres to coils. Peel caps are drilled for 2 ports one to vent air-bubbles and the other fed by funnel or cattle syringe w/o plunger but still a slow fill but no big nuts to crack.

Bob Z. said:

Re-filling the forks with oil with the long springs in place can be messy and slow.
Did you use any special home-made deal to help trickle in the oil?

Click to expand...

Nope, just a small funnel with a short section of rubber hose pulled into the spout. It only takes about two minutes per leg to fill.

Bob Z. said:

Also, draining through the small screw hole can require pumping the forks up and down several times. Then you get some good velocity squirts that a drain pan can't catch.

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Get a big pan with a built-in lip. http://www.autozone.com/shop-and-garage ... 34895_0_0/ Left leg: turn the bars all the way to the right, then, with the bike on the side stand, pull the plug. Straddle, lock front brake, and pump. Right leg: start on the center stand, then follow same general procedure.

Nathan

Just my twopence , if the seal is of the single lip type,when water collects above it this can be "sucked" in when the fork extends, The single lip face's down and can be drawn off the stanchion when the fork extends ,due to vacuum . This will either draw in moisture or water.
Duel lip [one edge facing down ,one up] are better,but add to the drag.
It's always an eye opener when all the rusty mess dribbles out. Good dust seals and GOOD chrome help. Once the main seal or dust seal as lost there edge it's open season for moisture , Just put the fork oil change on your Jobs list. I have just bored out over 1mm a side from an old slider and there is still a hollow from wear :!:

Norton original seals are single lip, the Honda seal used as a replacement are double lipped.