The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: VaSteve on April 22, 2007, 09:23:41 PM

Title: How much fork oil?
Post by: VaSteve on April 22, 2007, 09:23:41 PM
So I finally got around to changing the fork oil in the bike.  What a messy job.  I should have had a smaller funnel, cause I had fork oil all over the place.  

Anyhow, I had the bike on the center stand with the front fork fully extended as I was told.  I filled the forks up with 15W fork oil from the dealer and it seems stiff.  A lot stiffer than before.  Almost too stiff.  

I read in Clymer how much I was supposed to put in (fat chance measuring that).  It was all the way up to the threads on the cap.   In fact, I dabbed some out with a paper towel when I put the caps on.  Did I put in too much?  If so, how much should I take out?

thanks
Steve
Title: Re: How much fork oil?
Post by: Bob_Roller on April 22, 2007, 09:49:14 PM
My BMW shop manual shows 190 cc for just an oil change on the forks. I'll go out to the bike and and see what the owners manual has to say about it. Owners manual states 190 cc as well. If you have that much oil in your forks, don't ride it until you have reduced the level, or you will probably have a severe leak before you know it! My only suggestion is to drain it and start over, or you may be performing a fork seal change shortly.
Title: Re: How much fork oil?
Post by: nhmaf on April 22, 2007, 09:58:57 PM
Oooh yeah.... you've got waaaaaay too much oil in there !

Remember from high school that liquid is incompressible (well, mostly, anyhow) ?
You gotta have some air space in those sliders for the spring to compress and the
fork sliders to move !   There are many schools of thought on how much oil and of
what weight it the best amount for different types of riding, but the basic specification
for those fork tubes is about 200cc per fork tube.   Get a smaller tipped funnel - you can
get one with long flexible hose ends at most automotive stores, and a cheap clear plastic
measuring cup with metric (cc) markings from a hardware or kitchen supply store.   Fully drain out both your fork tubes and start over again !    

If the forks have been totally disassembled, the spec indicate maybe a little
over 200 cc of oil is needed, versus a little under 200cc for a simple oil change procedure.   In any case, by my estimates you have about 5X the amount of oil that should be in there.

Did you drain the original oil and check how much came out ?
Title: Re: How much fork oil?
Post by: Ed Miller on April 22, 2007, 09:59:55 PM
I, like Bob, went out and checked my owner's manual.  190 cc is right.

It's easy to measure if you buy a syringe at a feed store; mine measures up to 60 cc.  I don't want to know what the real purpose is for these syringes.

Title: Re: How much fork oil?
Post by: VaSteve on April 22, 2007, 10:02:34 PM
Ah, OK, thanks.   I have plenty of syringes (makes giving a baby medicine easier).  

190cc...is that per side?

Title: Re: How much fork oil?
Post by: Justin B. on April 22, 2007, 10:07:10 PM
The others are correct, if you filled it all the way to the top then it is WAAAAY too full and I'm surprised you haven't blown out your fork seals yet!!  Time to start over.  I went to the local TSC store (that's Tractor Supply for you yankee city-boys  ;)) and got a 60 cc syringe (no needle) and it works great for filling forks, fits into the itty-bitty filler hole with no problems and lets you measure it exactly without spilling a drop.

Now, once you get the correct amount in I would imagine that the 15w will still be a bit stiff.  I have 7.5 w and think that being a "full sized" person 10w might have been better.  You could get some 7.5w and mix with the 15w if you were wanting something a bit stiffer than the 7.5w...  I actually found that the BMW fork oil was cheaper (at least around here) than the stuff carried by the jap shop - that was a shocker!!!  Or, they were having a hard time getting rid of the 7.5w, I bought a couple jugs of it...
Title: Re: How much fork oil?
Post by: Bob_Roller on April 22, 2007, 10:23:15 PM
Yes, thats 190 cc per fork.
Title: Re: How much fork oil?
Post by: Rob Valdez 79 R65 on April 23, 2007, 09:18:15 PM
And watch the torque on those drain bolts.  Not too much!!!
Title: Re: How much fork oil?
Post by: VaSteve on April 25, 2007, 06:43:48 AM
Thanks guys, I'm hoping to get to it this week.  Meanwhile, the bike is parked.  Hopefully, you won't have to walk me through a seal replacement...but I'm sure that's within my capabilities (or not) as well.
Title: Re: How much fork oil?
Post by: Bob_Roller on April 25, 2007, 12:08:40 PM
Could I make a suggestion here? How about make a posting about the job you are going to do, and especially if you've never done the job before, or your not too sure of your mechanical abilities, and get the info you need and helpful tips that are not included in the manuals, before you start the job,and not waste time and effort and possibly cause unnecessary damage to your bike. Possibly it could be it's own section of this forum, or a subsection of one of the existing technical categories.
Title: Re: How much fork oil?
Post by: VaSteve on April 25, 2007, 02:58:31 PM
Quote
Could I make a suggestion here? How about make a posting about the job you are going to do, and especially if you've never done the job before, or your not too sure of your mechanical abilities, and get the info you need and helpful tips that are not included in the manuals, before you start the job,and not waste time and effort and possibly cause unnecessary damage to your bike. Possibly it could be it's own section of this forum, or a subsection of one of the existing technical categories.


Wow, I don't know if that was a general suggestion or directed at me specifically.  

Frankly, I didn't think it was that big of a job and i don't always have time to clear my jobs through the collective.  But I'm pretty sure of my mechanical ability in most cases.  

FWIW, I did suggest something like a sticky section of common issues...not using the gasket that comes with the oil filter for instance.   But i never got implemented.  

I'm going to take the rear shocks off next and replace the springs...are there any tricks to that?   Can I actually separate the spring from the shock?  I see them for sale assembled.  


Title: Re: How much fork oil?
Post by: Bob_Roller on April 25, 2007, 03:25:29 PM
No Steve, not aimed at you it, just has brought back quite a few instances over the years when somebody has gotten themself into really serious situations that could have easily been prevented if they knew of a few little tips and hints ahead of time , instead of after the fact. Lets face it, the info available from what you would consider reliable sources, turns out to be incorrect sometimes. In my BMW shop manual, it shows 190 cc as the correct amout of oil per fork, but it also states .4 quart for the US measure. Well .4 quart is 380 cc, so even the factory manual is wrong here. What I'm trying to say here is, it might be a good idea to get some input from people that have done the job before, and steer an owner clear of possible trouble spots.
Title: Re: How much fork oil?
Post by: VaSteve on April 25, 2007, 03:28:57 PM
Quote
No Steve, not aimed at you it, just has brought back quite a few instances over the years when somebody has gotten themself into really serious situations that could have easily been prevented if they knew of a few little tips and hints ahead of time , instead of after the fact. Lets face it, the info available from what you would consider reliable sources, turns out to be incorrect sometimes. In my BMW shop manual, it shows 190 cc as the correct amout of oil per fork, but it also states .4 quart for the US measure. Well .4 quart is 380 cc, so even the factory manual is wrong here. What I'm trying to say here is, it might be a good idea to get some input from people that have done the job before, and steer you clear of possible trouble spots.


OK, no offense taken then....  Seems that R65's get short shrift in the manuals anyhow.  This hopefully isn't a catastrophe...it's no $2000 o-ring!!
Title: Re: How much fork oil?
Post by: nhmaf on April 25, 2007, 09:22:18 PM
VASteve -

Not sure what you have for rear shock absorbers, but many of them require some special
tools to compress the spring for (dis)assembly.  Since it is a big spring, it takes alot of
pressure, and can be a bit dangerous to do without proper equipment.   A number of
companies offer regular or heavy duty springs for the same shock absorber, and dealers
carrying them have the equipment to install/repair the shocks.   An example of this are
the Progressive (brand) shocks, which have regular and heavy duty springs for sale.
If you buy the shocks from Bob's BMW, for example, they will assemble them for you.

hope this info is helpful,
Mike
Title: Re: How much fork oil?
Post by: Justin B. on April 25, 2007, 09:56:14 PM
You will most likely need a spring compressor, as already pointed out.  It is basically a couple of chunks of all-thread with a hook and nut on each end.  I think Harbor Freight has them pretty cheap.  I have never looked at the factory shocks but Konis have like a big slotted retainer/washer on top that it looks like will slip right off once you relieve the springs.
Title: Re: How much fork oil?
Post by: Rob Valdez 79 R65 on April 25, 2007, 11:33:54 PM
Are these the original BMW shocks you are replacing the springs on?
Are you sure the damper is still any good?

I have heard more bad than good about the stock shocks, and while I loved that built-in adjusting handle, I was happy to see them go.
Title: Re: How much fork oil?
Post by: Ed Miller on April 26, 2007, 12:53:37 AM
The HF tool's hooks are too fat to fit between a pair of Koni spring coils.  I guess if you never intend to compress car coils, you could grind them small enough.

I don't remember reading that the BMW stock shocks are made to be rebuilt,  though if you could find new springs you could replace them anyway.

I ended up using a crazy combination of a bottle cap installer and something slipped between an upper pair of coils, I think a previous incarnation of my stupid bag mounts.  It worked surprisingly easy.  The bottle capper stood kind of like a little drill press, but the handle pressed the capper part down rather than a drill.  I just had the silly thing sitting around in my shop, I don't even use it for bottling beer.  

Title: Re: How much fork oil?
Post by: VaSteve on April 26, 2007, 08:38:05 PM
I have Koni's and a set of spring compressors I used for the car.   I was told Koni's are replacements for the stock shocks and are pretty good, so it's worth it to me to repaint the springs if I can take it apart.  

Title: Re: How much fork oil?
Post by: nhmaf on April 26, 2007, 10:12:21 PM
Konis   (unfortunately out of business now, but a "new" company called "Ikon" makes the
same design now) are indeed rebuildable and are generally good parts/worth refurbishing
if you can swing it.

http://suraklyn.com/yabb/Smilies/thumbsup.gif
http://suraklyn.com/yabb/Smilies/thumbsup.gif
Title: Re: How much fork oil?
Post by: VaSteve on April 29, 2007, 07:30:37 PM
Koni's not out of business!!  I just bought a set of Koni's for my car...  maybe they don't make bike shocks any longer?


BTW:  What do you all use to measure the amount of oil to put in?   I have a little dropper for baby medicine, but at 10ml at shot, it's going to take a while.   Unfortunately, I need another quart of this stuff, between the spillage and overfill, I'm a couple OZ short.  :(
Title: Re: How much fork oil?
Post by: nhmaf on April 29, 2007, 07:45:04 PM
A number of us in the "rural" parts of the country just go down to the local farm supply store
and you can often find syringes for dosing livestock that will measure 50cc or 60cc at a shot.
Or, I bought some clear plastic measuring cups and squeeze bulbs from a kitchen supply store
and keep them in the garage marked "OIL" so that no one tries to use them in our kitchen.
Title: Re: How much fork oil?
Post by: Justin B. on April 29, 2007, 07:45:54 PM
As pointed out by several earlier in this thread - 60cc syringe from feed store/Tractor Supply...  1ml = 1cc
Title: Re: How much fork oil?
Post by: VaSteve on April 29, 2007, 07:55:03 PM
Quote
As pointed out by several earlier in this thread - 60cc syringe from feed store/Tractor Supply...  1ml = 1cc


Yeah...forgot to go back and re-read.   :-[ :-[
Title: Re: How much fork oil?
Post by: Justin B. on April 29, 2007, 08:01:46 PM
Hehe, SMACK!  You can get graduated beakers and cylinders but I think the best bang for the buck (and minimum mess) is the syringe...
Title: Re: How much fork oil?
Post by: VaSteve on May 01, 2007, 09:54:53 PM
Syringe was good.  I looked like a fish out of water in the Tractor Supply store.

I think the seals died.   When I pumped the shocks the dispel all the oil I go some small black chunks.  I don't think they died from what I did...I didn't pump the shocks the first time...so maybe that stuff just didn't drain with the oil.    It's dark so I haven't ridden it, what does it feel like if they seals are gone.

Oh, I and I learned that if you're going to do that...pump the shocks while sitting on it....make sure the top cap is in.    Don't ask me what happens.  It's bad.   ::)  I'm going to go shower now.  
Title: Re: How much fork oil?
Post by: Bob_Roller on May 01, 2007, 10:09:08 PM
I don't think that what you saw were pieces of the seal, more likely globs of grunge that develop when the oil isn't changed on a regular basis. If it looked that bad, you may want to replace the oil again in  500-1000 miles or so.
Title: Re: How much fork oil?
Post by: Justin B. on May 01, 2007, 10:35:29 PM
Steve, don't forget to put your filler plugs in before any aggressive pumping!  [smiley=evil.gif]  I don't think you will actually "feel" anything if the seals got blown, they just won't seal anymore and you'll have fork oil splattered/sprayed everywhere after a ride.