Article [13] ST1300 - Pre-load Fluid Replacement

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Have ridden about 9K miles since adding fluid. Around half of those miles are two up with nearly 400 lb. combined rider weight, plus gear in bags. A little fluid must have leaked, because it takes about 1.5 turns (3 clicks) to get pressure. It took less than 1/2 turns (1 click) to get back pressure when I first added fluid. Wondered if anyone else had the experience of having to add fluid again that soon.
Unless you used NEW crush washers, there is a chance your used sealing washers are weeping fluid.
I've found this on members bikes that re-used the original washers again.
You can purchase new washers from McMaster Carr.
 
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dduelin

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I believe the fluid breaks down over time under heat and constant pressure. After topping mine off I adopted the practice of backing off the preload wheel to zero turns of preload when I park the bike in the garage. After 25,000 miles the preload adjuster still begins to work with less than 1 turn. While some fluid could conceivably leak out mine has never lost fluid.
 

mlheck

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Yes, I re-used the old washer and found the same as you. What was only a half turn became a turn and a half. I refilled it and used the washers once again. I may need to get some new washers.
 

Dinkie Diesel

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I should have read this info-mercial before working on mine after NatSTOC. I lost my ball!!! No worries, it still works and I don't think it will move on its own. As far as counting the clicks, I'm guessing I won't be able to tell if it is a click or two off. I had to screw mine in many turns before it started to engage before the work. I felt my way along as I did not read thread this before doing the work. I didn't take off any brackets or remove the hose from the fender supports. Thought it was quite simple though. I poured out the old fluid and filled it with ATF. Put it all back together and still had many turns before engaging. Took it all apart again and realized I should have stuck a small phillips screw driver down the hole to push the piston back out all the way. When I did that I think I moved it another 1/4". Refilled and reassembled and then I had success.
 
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I should have read this info-mercial before working on mine after NatSTOC. I lost my ball!!! No worries, it still works and I don't think it will move on its own. As far as counting the clicks, I'm guessing I won't be able to tell if it is a click or two off. I had to screw mine in many turns before it started to engage before the work. I felt my way along as I did not read thread this before doing the work. I didn't take off any brackets or remove the hose from the fender supports. Thought it was quite simple though. I poured out the old fluid and filled it with ATF. Put it all back together and still had many turns before engaging. Took it all apart again and realized I should have stuck a small phillips screw driver down the hole to push the piston back out all the way. When I did that I think I moved it another 1/4". Refilled and reassembled and then I had success.
You can purchase the single SS detent ball (BB) at most hardware shops.
Search this forum, as if I remember correctly, someone posted the correct size when they did that.
Hope this helps.
Igofar
 

Dinkie Diesel

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You can purchase the single SS detent ball (BB) at most hardware shops.
Search this forum, as if I remember correctly, someone posted the correct size when they did that.
Hope this helps.
Igofar
Thanks FarGo, Dave has it in his original post at 4mm or 5/32". You have to get up real early to stay ahead of DDuelin. I'll make my way to the hardware store one of these days.
 
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Finally got around to doing my adjuster today. Followed instructions from intotheabis but left the rod attached. My fluid looked new, just a might short in volume. Had a success the first time 'round. About 20 minutes. Thanks guys.
 
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Igofar- Thanks for your instructions on recharging the rear suspension pre-load valve

Igofar wrote excellent instructions and has a link to pictures in order to easily recharge the hydraulic fluid in the rear shock pre-load unit. Folks, this is so easy even a blind cave-man could do it! The difference is amazing: my 2003 had what I thought was good suspension until I added almost 30cc of hydraulic fluid, and followed his charging method. The difference is amazing; the rear suspension is alive and well, handing bumps, and rough road while increasing the rear suspension travel but not destabilizing the bike. I don't want to steal his thunder, so you'll have to ask him for the written instructions. But I do want to thank him for a renewed ride!
 
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dduelin

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The instructions are here in the first posts of this thread. There is another link?

The rear suspension travel is fixed by the specifications of the rear shock absorber and swing arm. Refilling the preload adjuster does not change the rear suspension travel but what happens over time is the preload oil breaks down and the adjuster loses effectiveness. We have to crank in more and more preload to get the same amount. There is only 36 clicks of preload available, it you have to use 18 to just begin adding preload you have lost half of the available preload. Refilling the adjuster with new oil allows preload to begin being added with 1 click or half turn of the adjuster. Since preload sets ride height this can affect where the bike sits in its available 123 mm of travel but it doesn't change the amount of travel.

Setting the shock up right does make a huge difference.
 
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The instructions are here in the first posts of this thread. There is another link?

The rear suspension travel is fixed by the specifications of the rear shock absorber and swing arm. Refilling the preload adjuster does not change the rear suspension travel but what happens over time is the preload oil breaks down and the adjuster loses effectiveness. We have to crank in more and more preload to get the same amount. There is only 36 clicks of preload available, it you have to use 18 to just begin adding preload you have lost half of the available preload. Refilling the adjuster with new oil allows preload to begin being added with 1 click or half turn of the adjuster. Since preload sets ride height this can affect where the bike sits in its available 123 mm of travel but it doesn't change the amount of travel.

Setting the shock up right does make a huge difference.
I used Igofar's instructions, and with very little edit, this made my job very easy.


1. Remove Seat(s)
2. Remove Left side cover (above knob) .
3. Unscrew the knob COMPLETELY (counter clockwise)
4. Notice the preload adjuster is on a bar, follow it up to the (1) 10mm bolt holding it in place, and remove it.
5. Notice the brake line is held in two small clips on the front of the rear fender, lift it out.
6. Pull the metal mounting rod towards you until in snaps out of its resting channel.
7. Turn the preload adjuster upside down.
8. Hold unit with large adjustable wrench, remove banjo bolt
9. Wrap a papertowel around bolt and both crush washers (leave washer in place so they seat the same way as before)
10. Dump ANY fluid or goop out of preload adjuster by turning upside down and screwing the knob ALL the way into the max position.
11. Unscrew Counterclockwise completely again.
12. Take chopstick, allen key, or small screw driver and PUSH the piston back as far as it will go (about 1 inch) You'll feel/hear it thunk.
13. Fill preload unit completely up with HYDRAULIC JACK OIL flush with the top. Let air bubbles rise, then top again.
14. Insert the bolt with washers still in place and snug down.
15. Turn the knob completely to the max setting again (clockwise)
16. Unscrew the knob completely again...
17. Dump oil out again, push piston back in again, fill with oil again. You just filled the line, and emptied the preload unit.
18. Fill the preload unit one last time, then insert the banjo bolt, check the direction of the line, hold it with your adjustable wrench and tighten the bolt firmly, but not too much, because it’s a hollow, soft bolt. You just want to seat the crush washers.
19. Now you should start feeling resistance about 1 or 2 clicks in.
20 STARTING POINT: From fully soft (counter clockwise - open) turn it clockwise 4 clicks, this means you'll get one with no resistance, and a couple with some resistance, then it will get firm. \
Start at 4 (default setting is 7 clicks or 3 and a half turns from fully open)
21. Now to to the right side of the bike, and find the hole in the frame that goes through to the bottom of the rear shock. If you check with a flashlight, you'll see a small punch mark on the screw and the frame for reference.
Gently turn the screw CLOCKWISE until it lightly seats (dots should match up)
Now, turn it COUNTERCLOCKWISE 1 and 1/2 turns ONLY (This is 3 half turns).
Default setting is 2 half turns out from seated if you want to go back.
Now go take the bike for a ride on some various types of roads (hwy, mountain, twisty etc.)
Check to see if your rising and falling as much as before, or how the wind affects your ride.
Just remember, It will behave differently than your used to, so be carefull and get used to it.
***Any suggestions are done at your own risk***disclaimer..dang lawyers etc.
Check your tire pressures before you go out. I run 40 front, 42 rear for a softer ride.
Hope this helps.

Igofar
 
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ST Gui

240Robert
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I used Igofar's instructions, and with very little edit, this made my job very easy.
What were your edits?



21. Now to to the right side of the bike, and find the hole in the frame that goes through to the bottom of the rear shock. If you check with a flashlight, you'll see a small punch mark on the screw and the frame for reference.
Gently turn the screw CLOCKWISE until it lightly seats (dots should match up)
Now, turn it COUNTERCLOCKWISE 1 and 1/2 turns ONLY (This is 3 half turns).
Default setting is 2 half turns out from seated if you want to go back.
What is that screw and what does it do?
 
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Full disclosure: I ain't no Honda mechanic. IMHO:

The pre-load affects compression, and as it seems apparent, you can compress a spring to have shorter travel, and a greater force is required to move/compress the spring's natural resistance compared to when unloaded. This is a highly technical area when dealing with constant vs. variable rate springs, and I believe the ST has a constant rate. None the less, the reason you add preload is to lessen the effect of every ripple in the road as excess spring travel is not safe at highway speeds.
The screw on the right is controls the damping effect for the rate of spring rebound, ie slowing down the upswing on the pogo stick effect. The entire center tube inside the spring is called the damper unit. The damping will affect your ride, and its worth your while to adjust it even an 1/8 turn to see if your ride can be improved.
 
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dduelin

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Preload and damping rebound are different for different weight of rider(s) and for the type of riding one is doing at the time. It is good that Larry identifies the settings as starting points because if you are not Larry on Larry's ride then you might like different settings.

http://www.youtube.com/watch?v=CAhksxRCIik&lr=1
 

ST Gui

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I'm familiar with the dynamics and interaction of preload, compression, damping, and rebound.

While the rear suspension travel is fixed at 4.8", its functionality is affected by sag and load. Preload is used to adjust the effective spring rate by a small degree, "giving back" some travel. This in turn allows the suspension to be more compliant, soaking up the ripples. I'd say uncontrolled travel is more accurate than excessive travel, as I'm of the opinion that properly done, more a little more travel for the ST wouldn't be a bad thing. But that can also be a matter of preference based on riding style and preference, i.e., a GoldWing to a Hailwood's 250-six, and somewhere in between.

Now that you mention the screw affects damping, I think that's mentioned in the Owner's Manual. I probably should look through it once in awhile.

Thanks for the info.
 

ST Gui

240Robert
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dd, thanks for posting that video. It demonstrates what I know about suspension, but I didn't have any clue that the effects of the damping adjustment screw would be so visible. Now to have a couple of buddies help me check that adjustment.

Is there a video that shows how to adjust sag?
 
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dduelin

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I'm familiar with the dynamics and interaction of preload, compression, damping, and rebound.

While the rear suspension travel is fixed at 4.8", its functionality is affected by sag and load. Preload is used to adjust the effective spring rate by a small degree, "giving back" some travel. This in turn allows the suspension to be more compliant, soaking up the ripples. I'd say uncontrolled travel is more accurate than excessive travel, as I'm of the opinion that properly done, more a little more travel for the ST wouldn't be a bad thing. But that can also be a matter of preference based on riding style and preference, i.e., a GoldWing to a Hailwood's 250-six, and somewhere in between.

Now that you mention the screw affects damping, I think that's mentioned in the Owner's Manual. I probably should look through it once in awhile.

Thanks for the info.
All adding preload practically does is increase ride height. A spring is measured by it's rate in force to distance compressed and the only way to change spring rate is to change it for another different rate spring. What preload does do is to increase the amount of force necessary to BEGIN compressing the spring. After that is overcome and the spring begins to compress it takes the same force to compress it the same distance - it's rate does not change. Preload is useful because the weight of the bike and rider are relatively constant so by adding preload the weight of bike and rider compress the spring a shorter distance. Sometimes we call this sag. Adding preload reduces sag and allows the bike to use more of the fixed amount of suspension travel the motorcycle has. If sag is 50% of available travel only 50% is available to compress when hitting a bump. If sag is 30% then the bike can use 70% of available travel to compress when hitting a bump.
 

PopJack

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I should have read this info-mercial before working on mine after NatSTOC. I lost my ball!!! No worries, it still works and I don't think it will move on its own. As far as counting the clicks, I'm guessing I won't be able to tell if it is a click or two off.
Not being nearly as clumsy as Dinkie, I did not lose my ball. I lost my spring though. I'm thinking one from a ball point pen might work- we'll see.
 
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I did mine a little over a year ago and it made a nice improvement. Over the 30k miles of hard use last year it needs attention again. Unfortunately it is now completely frozen. I can't get the knob to turn at all. I removed the knob and used penetrating oil on the ball and what I can get to of the threads, but that didn't help. I'll work at it some more, but it's stuck so bad I don't think it will move. I was afraid of breaking the knob!
 

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Great write up the artilce. Very easy project to take care of even for somewhat of an unexperienced guy to take care of. Now to test out the adjustments and see how it handles. ...........:06biker:
 
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Long story short, like many, I've been fiddling around with what to do with the rear shock on my '04 ST1300. I've tried swapping springs, but that generally gave a harsher ride, but not necessarily any better damping. I finally got around to flushing and repleneshing the preload fluid on my shock last night. Had seen several 'how-to's' and after looking them over, I kind of combined the methods. As mentioned in mid-thread on this thread, you don't have to remove the knob. In fact, the knob makes it a heck of a lot easier to crank the piston in and out. I then replaced the two crush rings on the banjo bolt and, to keep the line from dripping while disconnected, I simply wrapped a paper towel around the fitting and pushed it up between the knob's mounting arm and a piece of plastic that was in the area of my repair (BTW, if you don't replace the crush rings, you WILL get a leak after you button it all back up and put the bikes weight on the shock). I emptied and flushed the cylinder twice. The second time seemed to push more black gunk out than the first. Then did as mentioned by attaching the cylinder and filling the line by screwing the knob/piston to full max. Then removed the cylinder, unscrewed the knob, pushed the piston back, then refilled, attached, added preload until I felt resistance (3 clicks - 1 1/2 turns), then cracked the banjo. After doing this, I removed the cylkinder yet again, and topped it off. Then reattached the cylinder one final time. I now get resistance on the 2nd click (1 full turn) and have my preload set at 9 clicks (I weigh around 210 lbs with gear). went for a short ride and felt a noticeable difference before I'd ever left the driveway. Firm, not harsh. Controlled. Will make a 100-mile or so ride this weekend to verify. But overall, a simple, quick, maintenance task that no one should put off doing.
 
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