ST1100 right fork leg oil filling

[Graham Watson]

I want to fill the right fork leg with oil to the correct 190m/m measurement (Honda Service manual).
Obviously, I have to attach the fork damper so that the oil doesn’t come out but as the spring, collar and fork cap etc. are all assembled so its impossible to fill and measure.
Do I have to disassemble the spring and all its components?——-if so, it looks very difficult to reassemble the spring seat, collar, stopper etc.
Any tips or guidance would be appreciated.

Regards,
Graham Watson

 

[Hondeltor]

Any service manual measurement is only correct if the fork leg is fully collapsed with the spring removed.

The damper rod stays in the fork, it only unscrews from the cap and then the clip slips out from under the nut and the preload spacer and spring pull out. (Be very careful, they are under quite a bit of spring tension).

I have set fork oil levels before with the fork on the bike but its more work to check and reassemble than simply removing the fork before removing the spring. Once you pull the fork from the bike youre 75% of the way there anyhow.

 

[Hondeltor]

If you don't mind me asking, why do you suspect the oil level is wrong? Is the fork leaking? If it is, you might as well have the seals done too, it isn’t that difficult of a job.

 

[Roger]

Standard 1100 forks - the right side is specially awkward to reassemble. I gave up needing three hands for the job and just add right-side folk oil by volume with a large syringe LESS 10% of what the book says. I'm not tempted to pump in an exact amount and risk blowing a seal. Anyone would be hard put to tell the difference in ride quality between my set up and one done with 'correct' levels like Hondeltor mentions. IMOH of course..... But what oil do you use? ARGH!

 

[John OoSTerhuis]

When’s last time the fork suspension fluid was changed? The fork removed and crud flushed out? It’s not that hard to do a fluid R&R properly, and gives peace of mind. Edit:

Fork Seal R&R Tips ( ST1100 ) *

Fork Seal R&R Tips ( ST1100 ) *

www.st-riders.net

You can make a simple tool to hold the right fork damper rod, or borrow the free STOC R&R loaner tool kit. Two holder tool examples:

Error - ST-Riders Media Gallery

www.st-riders.net

John

 

[Hondeltor]

When’s last time the fork suspension fluid was changed? The fork removed and crud flushed out? It’s not that hard to do a fluid R&R properly, and gives peace of mind. Edit:

Fork Seal R&R Tips ( ST1100 ) *

Fork Seal R&R Tips ( ST1100 ) *

www.st-riders.net

You can make a simple tool to hold the right fork damper rod, or borrow the free STOC R&R loaner tool kit. Two holder tool examples:

Error - ST-Riders Media Gallery

www.st-riders.net

John

This is a good point, topping off fork oil is throwing good money after bad. It does wear out and need replaced.

 

[Graham Watson]

Standard 1100 forks - the right side is specially awkward to reassemble. I gave up needing three hands for the job and just add right-side folk oil by volume with a large syringe LESS 10% of what the book says. I'm not tempted to pump in an exact amount and risk blowing a seal. Anyone would be hard put to tell the difference in ride quality between my set up and one done with 'correct' levels like Hondeltor mentions. IMOH of course..... But what oil do you use? ARGH!

 

[Graham Watson]

Roger,
I realize that its 4 yrs ago since you posted the problem of filling the right fork leg with the correct amount of oil but after struggling for ages to reassemble the spring etc. , I have come to the same conclusion and using a syringe is the easiest way to refill the fork leg.
Regards,
Graham Watson

Standard 1100 forks - the right side is specially awkward to reassemble. I gave up needing three hands for the job and just add right-side folk oil by volume with a large syringe LESS 10% of what the book says. I'm not tempted to pump in an exact amount and risk blowing a seal. Anyone would be hard put to tell the difference in ride quality between my set up and one done with 'correct' levels like Hondeltor mentions. IMOH of course..... But what oil do you use? ARGH!

 

[Graham Watson]

When’s last time the fork suspension fluid was changed? The fork removed and crud flushed out? It’s not that hard to do a fluid R&R properly, and gives peace of mind. Edit:

Fork Seal R&R Tips ( ST1100 ) *

Fork Seal R&R Tips ( ST1100 ) *

www.st-riders.net

You can make a simple tool to hold the right fork damper rod, or borrow the free STOC R&R loaner tool kit. Two holder tool examples:

Error - ST-Riders Media Gallery

www.st-riders.net

John,
As well as trying to repair the water pump on my ST1100, I am also overhauling the forks and find that the left fork is easy enough to refill but refilling to the correct measurement on the right fork is a different kettle of fish as you know.
There are tools available that make the job easier but what I found the best way to fill the fork was to disassemble the right fork, clean all the parts, of course, and then totally reassemble but leave the top cap unscrewed to the fork leg.
Pour the required amount of oil into a measuring jug and pour the oil down the tube then screw the cap on the fork.

Regards,
Graham Watson

 

[Graham Watson]

Roger,
I realize that its 4 yrs ago since you posted the problem of filling the right fork leg with the correct amount of oil but after struggling for ages to reassemble the spring etc. , I have come to the same conclusion and using a syringe is the easiest way to refill the fork leg.
Regards,
Graham Watson

Roger,
I found the best way to refill the right fork is to pour the correct amount of oil into a measuring jug, unscrew the fork cap and just pour the oil down the tube then reattach the cap.

Regards,
Graham Watson

 

[Bush]

Graham,

You said "There are tools available that make the job easier but what I found the best way to fill the fork was to disassemble the right fork, clean all the parts, of course, and then totally reassemble but leave the top cap unscrewed to the fork leg. Pour the required amount of oil into a measuring jug and pour the oil down the tube then screw the cap on the fork."

If you disassembled the right fork, why didn't you just use the recommended method of filling, which is done before putting the spring back in, by measuring the fluid height from the top of the collapsed fork tube? It is the only accurate way of ensuring the proper amount.

Posting tip - Do not add your content within the QUOTED section of a previous post, or part thereof, which you are importing into your post.

 

[Graham Watson]

Graham,

You said "There are tools available that make the job easier but what I found the best way to fill the fork was to disassemble the right fork, clean all the parts, of course, and then totally reassemble but leave the top cap unscrewed to the fork leg. Pour the required amount of oil into a measuring jug and pour the oil down the tube then screw the cap on the fork."

If you disassembled the right fork, why didn't you just use the recommended method of filling, which is done before putting the spring back in, by measuring the fluid height from the top of the collapsed fork tube? It is the only accurate way of ensuring the proper amount.

Posting tip - Do not add your content within the QUOTED section of a previous post, or part thereof, which you are importing into your post.

Bush,
Many thanks for your reply.
The damper rod MUST be installed with the socket bolt & washer securing it.
Then a dimension is taken (190m/m) using a tape measure from the collapsed tube to give the correct oil height.
That is when the problems arise———-it is impossible to then put in the spring, spring collar, stopper etc. because the threaded top part of the damper rod disappears under gravity.
After numerous attempts at trying to get round the problem, I then resorted to ST-owners.com to look for guidance and a few people have made tools to help and also it’s possible to borrow the tools.
One member wrote that he got round the problem by using a syringe to get the correct volume.
In my case, I got a family member to help compress the spring and assemble the internals of the fork then secure the whole thing in the fork using the socket screw/washer.
Then I poured 385 cm3 of oil into a jug and poured it into the top of the fork tube and then screwed the fork cap into the fork tube.
Job done.
If you know a better way of doing the job, please tell me as more oil went on the floor than in the fork leg!
As I mentioned, tools are available from members to help doing the job.
Again, many thanks for your reply.

Regards,
Graham Watson

 

[Bush]

Hello Graham,
It seems you have misunderstood the procedure somewhere along the line. Obviously, you can't measure the oil height with the spring and rod installed for two reasons. First, you can't get a measure down the tube with the spring there and secondly, you are supposed to measure it with the fork tube fully collapsed, which it won't be with the spring installed.

The oil is added while the spring is out, fork collapsed and measured to a height of 7.5 inches down from the top of the tube. Now, here is the part that seems to have stymied you. To hold the damper rod up, before you add the oil, attach the nut to the top of the rod and wrap a piece of wire around it. This allows you to hold it up (or your helper's third hand can do it), while you add the fluid and gently pump the fork to remove air, to get a proper oil height.

Once filled to the proper level, have your third hand continue to hold the wire, while you thread the spring over it and into the fork tube. Then, if you have the wire only slightly wound under the nut, you compress the spring while your helper inserts the washer under the nut and pulls out the wire.

Also, IIRC, there is a spacer involved just below the washer too, on the right leg.

No other tools needed at all, except the helping hands.

 

[Bush]

Another tip for getting the washer under that nut, while compressing the spring - set the nut at the top of the threaded rod, a few threads on, allowing greater clearance to get the retaining washer in place. Then screw the nut down so that about a 1/2 inch of threads appear above the nut.

 

[John OoSTerhuis]

It’s in the picture I posted but the simple home-made damper rod holder tool’s use may need explanation:

One long 10mm bolt (1.0 pitch) and two nuts for it. Screw one nut halfway onto the end of the damper rod. Spin the other nut up on the bolt shaft, screw the bolt into the nut on the damper rod and then spin the other nut down until it contacts the other and locks the bolt in place. Hook a length of coat hanger under the head of the bolt and you’re in business.

I do this easily by myself with a strap from the rafter holding the end of the coat hanger or custom Andy Hand version.

Note the manual specs the OEM damper rod nut leave 10.5mm (0.41 in) of the rod’s threads exposed for the fork cap to screw onto. There have been one or two reports of damper rods becoming detached from the fork cap (204 in lbs!).

FWIW, I’ve always pulled my forks to replace the suspension fluid. I do a dump-n-flush x 3 with ATF and let them drain overnight, fully extended and slightly elevated so the last dregs drip out the lower drain plug holes. You’d be surprised at the tiny shiny bits you might find in those last drops.

Anyway... every time I’ve done this, as a test I measure out the ‘capacity’ figures in the manual and pour it in, pump out the air and let them settle. In every case when I used my siphon to adjust the spec’d level I had to withdraw a full fluid ounce. A fluid ounce equates to about a one inch change in the level inside a 41mm fork tube. So instead of 7.5” of air you may only have 6.5” using just the ‘volume’ method. You can infer what you will from that info.

FWIW 2 - as long as one is pulling ST1100 forks (especially if you’re replacing seals) I recommend taking the anti-dive unit apart to inspect. Mine wasn’t functioning properly as the piston lip’s seal was chipped.

John

 

[Graham Watson]

It’s in the picture I posted but the simple home-made damper rod holder tool’s use may need explanation:

One long 10mm bolt (1.0 pitch) and two nuts for it. Screw one nut halfway onto the end of the damper rod. Spin the other nut up on the bolt shaft, screw the bolt into the nut on the damper rod and then spin the other nut down until it contacts the other and locks the bolt in place. Hook a length of coat hanger under the head of the bolt and you’re in business.

I do this easily by myself with a strap from the rafter holding the end of the coat hanger or custom Andy Hand version.

Note the manual specs the OEM damper rod nut leave 10.5mm (0.41 in) of the rod’s threads exposed for the fork cap to screw onto. There have been one or two reports of damper rods becoming detached from the fork cap (204 in lbs!).

FWIW, I’ve always pulled my forks to replace the suspension fluid. I do a dump-n-flush x 3 with ATF and let them drain overnight, fully extended and slightly elevated so the last dregs drip out the lower drain plug holes. You’d be surprised at the tiny shiny bits you might find in those last drops.

Anyway... every time I’ve done this, as a test I measure out the ‘capacity’ figures in the manual and pour it in, pump out the air and let them settle. In every case when I used my siphon to adjust the spec’d level I had to withdraw a full fluid ounce. A fluid ounce equates to about a one inch change in the level inside a 41mm fork tube. So instead of 7.5” of air you may only have 6.5” using just the ‘volume’ method. You can infer what you will from that info.

FWIW 2 - as long as one is pulling ST1100 forks (especially if you’re replacing seals) I recommend taking the anti-dive unit apart to inspect. Mine wasn’t functioning properly as the piston lip’s seal was chipped.

John

John,
Thanks for your ( and others too numerous to mention) help repairing both the water pump and the forks on my ST1100.
I saved a fair chunk of change rebuilding the pump myself.
As I mentioned previously, I totally stripped the forks and fitted new seals, bushings etc.
Filling the left fork to the correct (187m/m) dimension was no problem but the right one was a different kettle of fish:- I solved the problem by getting a jug with the right amount (385 cc) of oil and leaving the fork cap off and just pouring it in.
Maybe you could tell me if this was a no-no!
Only done a couple of miles on the bike but seems OK.
Next thing on my repair list is the leaking fuel cock assembly so I’m researching a repair kit as the genuine Honda part is around the $142 mark.
As before, many thanks for your help.

Regards,
Graham Watson

 

[Bush]

Maybe you could tell me if this was a no-no!

I imagine John will reply to this also, but if that right fork was totally disassembled for bushings and seals, all the old fluid should have been removed and using the volume method to refill should be OK. It is when you are just replacing the fluids, without disassembly that you really should measure the fork oil height, to have the correct amount in there.

 

[John OoSTerhuis]

I don’t get it. Why didn’t you just pour in the suspension fluid and adjust to the level spec’d, before you installed the spring?

As you did have it apart, pouring in the quantity of suspension fluid listed as “capacity” in the manual through spring coils should be OK.

John