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Changing fork oil

L

larsp

Guest
Guest
It's (way past) time to change the fork oil in my 2012 Connie.

I don't trust the mechanics at the dealers in Denver to have the knowledge, tools, or the desire to do the job right.  The dealerships sell just about every brand of wheeled vehicle around and I doubt the mechanics have much expertise in any of the equipment they work on, and the pressure to get the job done quickly compounds the situation.

I've read the FSM about how to remove the forks and disassemble the fork with the special tool.  I've also watched a few YouTube videos about how to change the oil in inverted forks (none specific to the Connie).  The videos say to take the top off, drain, exercise, drain, exercise... several times and this will remove about 90% of the oil in the fork.  One video said that if you hang the fork upside down overnight then you would drain about 99%.

I'm guessing that completely disassembling the fork is the quick way to get all the oil out, but I'm not in any hurry (riding season doesn't start here until March) so the YouTube approach is certainly fast enough for me. 

My questions are:  (1)  is the YouTube approach suitable for Connie forks?  (2)  is there anything unique about Connie forks that changes the approach?  (3)  Is there anything to be gained by changing the volume or the viscosity of the replacement oil? 

Thanks

Lars
 
lars said:
It's (way past) time to change the fork oil in my 2012 Connie.

I don't trust the mechanics at the dealers in Denver to have the knowledge, tools, or the desire to do the job right.  The dealerships sell just about every brand of wheeled vehicle around and I doubt the mechanics have much expertise in any of the equipment they work on, and the pressure to get the job done quickly compounds the situation.

I've read the FSM about how to remove the forks and disassemble the fork with the special tool.  I've also watched a few YouTube videos about how to change the oil in inverted forks (none specific to the Connie).  The videos say to take the top off, drain, exercise, drain, exercise... several times and this will remove about 90% of the oil in the fork.  One video said that if you hang the fork upside down overnight then you would drain about 99%.

I'm guessing that completely disassembling the fork is the quick way to get all the oil out, but I'm not in any hurry (riding season doesn't start here until March) so the YouTube approach is certainly fast enough for me. 

My questions are:  (1)  is the YouTube approach suitable for Connie forks?  (2)  is there anything unique about Connie forks that changes the approach?  (3)  Is there anything to be gained by changing the volume or the viscosity of the replacement oil? 

Thanks

Lars
Click to expand...
Post a link to the video you are asking about.  The YouTube approach is just a tad too general for anyone to comment on.  I don't think the connie forks are unique, but haven't had them apart.  I'm sure some tuning can be done by altering the volume / viscosity of the fork oil.  Unless you know what you're doing, I'd just stick with stock specs on that.  Suspension tuning is a bit of an art that takes some time to learn.  This might help.
http://v4musclebike.com/articles/RACETECH-SUSPENSION-BIBLE.pdf
 
No need to completely disassemble the tubes if you're only doing a fluid change. Open the top cap, measure what you drain out and replace with the same amount. Thats the easy part....
 
I recommend replacing the seals even if not that old.  Just do the complete rebuild.  I did an oil only change on mine at 48k and the seals started to leak at 55k.  I had to have them replaced on the road.  Cost me twice more than all the parts and tools needed to do the job.
 
The correct way is to completely disassemble the fork, Clean and Inspect, and replace seals and oil
 
Forks are a reciprocating, mechanical device and fluid does become contaminated, whether it looks like it or not.
Valving doesn't compensate for debris flowing passed. After time, that valving will be restricted.
Disassembly allows you to clean the lower tube of the very fine metal particulates that adhere to those inner surfaces.
I use an aerosol brake cleaner to squirt/reach down and flood the lower tube. Brake cleaner is clear going in and somewhat gray coming out.
I change fork oil annually in my dirt bikes and biennially in the C14. It makes a huge difference that you'll notice.
 
JDSCO said:
Forks are a reciprocating, mechanical device and fluid does become contaminated, whether it looks like it or not.
Valving doesn't compensate for debris flowing passed. After time, that valving will be restricted.
Disassembly allows you to clean the lower tube of the very fine metal particulates that adhere to those inner surfaces.
I use an aerosol brake cleaner to squirt/reach down and flood the lower tube. Brake cleaner is clear going in and somewhat gray coming out.
I change fork oil annually in my dirt bikes and biennially in the C14. It makes a huge difference that you'll notice.
Click to expand...
Great advise.  :beerchug: :beerchug:
 
I would say dis-assembling the forks isn't really necessary, but you need to do a good job cleaning out the old fluid, especially if it has turned black.  I have had good luck using Mystery Motor Oil ( MMO ).  Dump the old fluid, pour in some MMO and then pump the rod & fork tube.
You may have to repeat until the MMO comes out looking close to what it looks like fresh.  Then I pour in some cheap ATF and repeat.

On the C-14, remember to "pump out" the fluid left in the cartridge during the MMO and ATF flushing.  And pump the rod after pouring in the new fluid to fill the cartridge.  Fred Harmon explains this in his video, BTW.
 
Marvel Mystery Oil  I sold a ton of that stuff during my family's Western Auto days.
DSC07932.jpg
 
:rotflmao: :rotflmao: :rotflmao: :rotflmao:

never been a supporter of pouring various liquids into thing like forks, or anywhere else on a bike.. alo never been a fan of MMO... maybe for lubing a lide on an old 1911 .45 autoloader, but that's my extent for it's usage....does smell nice tho... :rotflmao:

as for the "cheap" ATF fluid flush, just curious which to use (joke), Ford type, or GM type? (again, just joking....).... :-X :truce: :truce: :rotflmao:

I figure this way, if you aren't going to disassemble to do the cleaning, maybe just invert and drain, and cyclically fill and flush until it comes out "clean", using the exact same fork oil you plan to use for the final fill...
Mixing juices in fork and such, is just a bit "iffy". JMHO. YMMV. LS/MFT, some settling may occur in shipping, etc.,

peace, :great: :great: :great: :great: :beerchug:
 
Using fork oil for flushing gets (very) expensive.  And it may not be that effective.

I first tried using ATF, but ATF just wouldn't clean out the old dirty fork oil.  I wanted to get as much as the old dirty fork fluid out as possible, that's why I tried using the MMO and I'm glad I did - it worked great.    I didn't want to leave any residual MMO in the forks, so I used the ATF to flush out what was left of the MMO.  Seemed to work just fine.  I suppose I could have used a bit of fork oil to flush after that, but I didn't.    I'm pretty confident not using some fork oil to do a final flush wasn't a problem, but when I do my C-14 forks, if I have a partial bottle of a different weight fork oil laying around, Ya,  I'll probably use that for a "final flush".

I had some old Ford FFA ATF laying around that my old '85 Jag used, so I used that, BTW.
 
This is not a recommendation to use ATF. 
In the shop manual for my GL650, it says to use ATF.  Surely there was fork oil in 1983!  I just can't remember.  Yes I'm putting fork oil in all of my forks! :)
 
I'll admit, back in the 70's, we did use ATF, to flush, and to use as fork oil...
especially on our MX/Enduro bikes, and even our Road Warrior's at the time.
:great: :beerchug: :beerchug: :))
 
as long as the spec is for 7-10 weight oil atf is still fine to use, can't hurt a thing and is still fairly inexpensive for even the synthetic stuff.
 
Just want to be clear,  I use ATF only for flushing out as much as the MMO that remains,  after I use the MMO to clean out all the old, dirty fork fluid.  I figure leaving a small amount of ATF to mix with the new fork fluid is a much better idea than having some old dirty fork fluid mixing with the new fork fluid.
 
IBAJIM said:
Just want to be clear,  I use ATF only for flushing out as much as the MMO that remains,  after I use the MMO to clean out all the old, dirty fork fluid.  I figure leaving a small amount of ATF to mix with the new fork fluid is a much better idea than having some old dirty fork fluid mixing with the new fork fluid.
Click to expand...
You've got a good point there.
 
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