Pre-Load Fluid Replacement Follow Up

[Igofar]

I was getting frustrated with my pre-load adjusting knob going 8-10 clicks before I felt anything so I decided to follow suit and remove the unit and replace the oil like others have done. The bottom of the shock was a little grungy, could be from road dirt however. Cleaned up with just a spray of contact cleaner. Didn't see any oil leaking anywhere. I unbolted the (2) bolts holding the unit, pushed it through to the right side and simply lifted it out between the shock and the battery box. I didn't have to remove anything else. I held the units flats with a cresent wrench and removed the banjo fitting. Both copper washers were clean and undamaged so I re-used them.
I poured out about a thimble worth of some really nasty, milky looking oil and sediment into a clear glass bowl. I pushed the plunger back down with a plastic chop stick so I would not damage anything inside the unit. It was stuck, but gentle pressure moved it back where it should be. I worked the screw and pushed it back several times with new oil to clean it out some. After I felt it was clean, I opened the screw all the way, pushed the piston fully open and filled it to the top with clean hydraulic jack oil from the machine shop. I re-attached the banjo fitting, pushed it back through to the left side, and attatched the two bolts again. I installed the spring, ball bearing and knob and tightened the phillips screw. I crossed my fingers....I turned the knob 1 turn and felt resistance on every click.
After I finished I started wondering if maybe Honda left that air space in there for a reason? Maybe it heats up and expands? Maybe I'll blow my seal and ruin my shock now? What have I done
I'm sure I'm just over thinking this, but has anyone who has topped off their pre-load unit had problems afterward? Blown seals, gaskets, etc.
Just need a little reasurance or a group hug perhaps.
Did I do the right thing?

 

[brandanharmon]

I topped off my preload adjuster about 4 months ago and it has held up perfectly. I filled it all the way up with not problems so far. The amount of fluid in the resv. struck me as being a very little bit. I think you did the right thing and that you should not worry about it.

 

[Killtimer]

Did I do the right thing?

Yes

 

[RaYzerman]

I think you're good. Any expansion (on the shock end) will simply translate into a teeny bit more preload, no worries.

 

[Igofar]

I put on approx 1K miles this week, and so far no oil leaks. (I didn't replace the washers)
I did notice one thing that may be important however. Before I re-filled my unit up with oil, it took 8-10 clicks before I felt resistance on the large knob. This seems to be similar to several other folks bikes. Prior to the re-fill, I could also run the knob all the way up to MAX hard, or the last line on the unit. Now, since I've topped the fluid off, the knob bottoms out with 1 1/2 lines still showing!
I'm really starting to wonder if HONDA left that space in there for any reason????

 

[SupraSabre]

I put on approx 1K miles this week, and so far no oil leaks. (I didn't replace the washers)
I did notice one thing that may be important however. Before I re-filled my unit up with oil, it took 8-10 clicks before I felt resistance on the large knob. This seems to be similar to several other folks bikes. Prior to the re-fill, I could also run the knob all the way up to MAX hard, or the last line on the unit. Now, since I've topped the fluid off, the knob bottoms out with 1 1/2 lines still showing!
I'm really starting to wonder if HONDA left that space in there for any reason????

From Sunday 8/21/2011 Coffee Thread:

Bob you should have come up to the RTE in Woodside today as IGOFAR Larry filled the preload adjuster on about four ST including mine and it made a big difference in the ride. He did it for no charge!!

Larry,

When you filled the preload adjusters at the RTE, did you remove the shock, or just the preload adjustment knob assembly?

Since Mother Honda will not replace my shock, I'm thinking of doing this. Any tips?

Thanks!

 

[Igofar]

Don't have to remove the shock.
Takes about 10-15 minutes tops.
Remove seat
Remove Right saddlebag
Remove left side cover
Remove right side cover
Remove single bolt on rear master cylinder
Go to left side of bike.
Turn adjustment knob all the way counter clockwise till it stops.
Now carefully remove the JIS phillips screw.
Place rag under knob assembly (to catch detent ball and spring)
slowly pull knob straight off, watching to the bb to fall.
remove bb and place in safe spot.
take toothpick and remove small spring under bb (or you'll loose it when you move unit)
now remove the (2) 10mm head bolts that hold the preload adjuster in place.
look through to the bottom of the rear fender, you'll see two tabs that hold the hydraulic line in place. slip line free (pull up)
now simply push the unit through to the right side (you made room by removing bolt from the master cylinder) hand it to someone else, its eaiser that way.
lift unit free and up, above the shock.
Use cresent wrench on the flats to hold it in place and take a 10mm boxend or socket to remove the banjo fitting and (2) copper washers.
wrap a rag around the end of the hose and stash it under the rear area of the tank for now.
pour out old oil (if you have any)
take a 14 mm wrench or socket and gently turn the adjuster bolt all the way in and pour out the rest of the white milking stuff, clean or rise body out if really bad.
now unscrew the bolt all the way until it stops.
Now take a chopstick, or blunt allen wrench and insert it in the hole and gently push down. (this is how much travel you lost) each click is 1mm. You have about 30mm total travel on the shock.
pour in hydraulic fluid, REPLACE both 6mm copper sealing washers (it will leak if you reuse the old ones, trust me on this). and with the unit's writing and line facing you,
point the fitting/line to 2 o-clock, then hold the body with the cresent wrench, and SNUG down the HOLLOW brass banjo bolt. DO NOT tighten too much or you will break it and or cause it to leak.
Push it back through, replace the bolt in the M/C. replace the side cover, saddlebag and seat.
replace the two bolts holding the unit on, push the line back in the tabs on the fender, then insert a dab of vasoline or grease in the hole and push the spring back in, the grease will help hold it in place. Place the bb on top, push it down with your thumb, and while holding it down, gently push the knob forward and over it.
then replace the screw ( I like to throw the cheap phillips away and use a 6mm allen from the hardware store).
thats it.
Note: The shock guy I know said that the reason these things leak, is they are in a bad spot next to a hot engine, and the owners CRANK them up to almost max thinking it will improve the handling. After testing and measuring this set up on dozens of different bikes, riders, and loads. I use the following....
7 clicks (3 1/2 turns) is standard honda
9 clicks for solo empty (I weigh 225 on a good day)
11 clicks for solo light stuff in bags
13 dual riders light stuff in bags
15 dual riders, max load in bags.
This still leaves enough room in the preload until that your not going to crank it up leaving you 3mm of travel before blowing your seal or causing it to weep out over time.
the 11 and 13 click settings leaves me/us with measured 25-30mm sag.
I also take the dampener screw which comes (1) full click out from fully seated, and turn it another 1/2 turn out. Seems to keep the wheel on the ground better.
Hope this helps....If not, ride down and I'll show ya
Igofar

 

[dduelin]

I unscrew the adjuster to remove all preload from the spring generally after each ride and in the 20-something thousand miles since my rebuild the adjuster still works the same amount - that is it takes up at the same point (4 clicks from completely backed off) and moves the preload collar the same distance as when new.

 

[wjbertrand]

I don't think you would blow a seal. If the oil heated up and expanded wouldn't it just push the piston out a bit farther increasing preload a bit?

 

[SupraSabre]

Don't have to remove the shock.
Takes about 10-15 minutes tops.
Remove seat
...
Hope this helps....If not, ride down and I'll show ya
Igofar

Excellent, I'll have to see about getting the replacement washers and try it!

Thanks a lot! :clap2:

I'll have to see if I can take a few pictures while doing...unless someone from the RTE took some?

 

[Igofar]

I believe I found the washers 8mm copper sealing washers at Gaingers.
I'll check when I get home tonight, and provide you with the part number on the package if I still have it.

IGOFAR

 

[Igofar]

I unscrew the adjuster to remove all preload from the spring generally after each ride and in the 20-something thousand miles since my rebuild the adjuster still works the same amount - that is it takes up at the same point (4 clicks from completely backed off) and moves the preload collar the same distance as when new.

That just means your preload unit is LOW on fluid:

 

[Igofar]

I don't think you would blow a seal. If the oil heated up and expanded wouldn't it just push the piston out a bit farther increasing preload a bit?

You won't BLOW the seal, but what happens is the seal gets really soft due to heat, and when people crank their preload up near or all the way, your only giving your system a couple mm of travel space

I've serviced a couple dozen of these things just in the past 6 months so far.

One member even had his rear shock rebuilt by a big name company, and when he cranked it all the way up, his fluid went bye bye within a day or two!

If your attempting to get the correct preload sag, fill it up first, then measure it. Honda's 7 clicks is near perfect for 30mm of sag. At least with 225-250lb riders.

refill the unit with hydraulic oil, and don't crank it beyond 15 clicks and your preload will never change, or leak any oil.
This has just been my experience with these things YMMV.

 

[SupraSabre]

...

refill the unit with hydraulic oil,

....

By this, I assume "brake fluid" isn't an option? : "Hydraulic Jack fluid" is what you need?

 

[970mike]

Like Bob, I noticed Mikes' posting in the coffee thread. My adj. is useless and undoubtedly suffers from your diagnosis.
Thanks for the info and for adj. so many ST riders' rear shock.

I just checked the shock on my wife's ST and it is the same way useless!! Not a problem on hers as I am going to replace the rear shock with a Wilber shock that will lower her bike about 1" for her short legs!! I am sure 90% of the ST's out there are like that.

Thank you Larry for coming up with a fix for these stock shocks!!

Mike

 

[SupraSabre]

Some people just take a little longer to get "it"...

So, you fill the "unit" (adjuster) with the hydraulic fliud, what about the hose? no draining and refilling?

 

[dduelin]

That just means your preload unit is LOW on fluid:

This isn't the first thread on refilling the ST1300 preload adjuster. It's hard to get the thing full enough that it starts taking up at less than 3 clicks. However, I have some experience with losing preload adjustment over time - it just gets worse. By removing all preload on the shock between rides I have avoided the problem getting worse over time. On the original shock at 60,000 miles it took 18 clicks to take up. After 20-something thousand miles the slack of 4 clicks has not changed. I see that as a positive.

BTW, no one ever sees the stock preload adjuster leak or finds evidence of the fluid outside of the unit. All that happens is that it takes more clicks to start working. How is this? I did not think the fluid would compress over time but since it doesn't leak out - what happens?

 

[mlheck]

I replaced the missing oil in my preload this weekend and did wonder about one thing. It is next to impossible to keep air out of the system this way, and from working on far more brake system than I care to think about, I know that it doesn't take much air to mess up a sealed hydraulic system. I started to wonder if we might be adding some extra movement to the suspension system by introducing air into the system. The air will compress when additional load is added to the spring and then try to push back when the load is removed. Such as a bump in the road. There doesn't appear to be a good way to bleed the air out of the system. Just my $0.02 worth.

 

[Igofar]

hydraulic jack fluid ONLY! I don't know about fork oil, ATF, etc. I figure the preload unit is as close to a hydraulic jack, so I use that.
NEVER use Brake fluid!!!! Just picture what your frame and plastic would look like after it leaked!

 

[Igofar]

Some people just take a little longer to get "it"...

So, you fill the "unit" (adjuster) with the hydraulic fliud, what about the hose? no draining and refilling?

when you pull the unit out, and keep it ABOVE the shock, no fluid leaks out of the hose.
If you do loose fluid in the hose, you simply fill up the unit, attach the hose, and turn the 14mm nut (adjuster) in a few turns until you feel it working,
then remove the fitting again and top it off. You just forced the oil back in the hose with the bolt.