R1200RT fork oil volume

[2bigalow]

Anyone know what the fork oil volume is for a 1200rt?

 

My Hayes manual says .62 liters, but that doesn't sound right. Seems to be too much.

 

Anyone?

 

 

 

 

 

[T__]

2bigalow, my 1200RT BMW service manual shows .46L of 10 weight hydraulic oil per leg.. I haven’t ever measured the volume so at this time have to take the official BMW service manual at it’s word..

 

Twisty

 

[xoomerite]

The BMW repair cd says 0.62 liters of hydraulic fluid. This does not show up as a maintenance item, just when replacing the slider tubes. Hope this helps.

[T__]

The BMW repair cd says 0.62 liters of hydraulic fluid. This does not show up as a maintenance item, just when replacing the slider tubes. Hope this helps.

 

Chris, that is very strange.. My BMW RepRom shows .46L for the RT & .65L for the GS..

 

Twisty

 

 

[xoomerite]

Maybe they cannot agree in Germany.

[T__]

Now this is very strange.. My 1st edition BMW service manual dated (01/2005) shows the .62L per leg..

My 4th edition BMW service manual dated (06/2006) shows .46L.. Wonder which one is correct?

 

Might take a call to the BMW dealer with your model year to sort this out..

 

Twisty

 

[2bigalow]

Thanks for the info.

 

.46 liters appears to be right.

 

I was replacing a damage lower leg and did not measure the oil when I emptied the other leg. I ASSumed the manual would have the correct measurements. Well, I measured out .62 liters and it filled the leg nearly to the top. At this point I knew something was wrong...

 

 

 

 

 

[T__]

2bigalow, technically you only need enough in there to lubricate the bushings & sliders.. The quantity does effect the front spring load & rate though.. As the air pressure starts to increase as the forks compress it adds some spring load & increases compression rate..

Too much oil will cause the air space to decrease to nothing at full compression & that can cause the front forks to hydro lock & possibly damage a seal or possibly bulge a slider..

 

Twisty

 

[1gabowles]

What year is your R1200RT? I ask this since mine says 0.62 L as well. where in your book/service manual does it say 0.47L?

[BrentW]

which size fork 41mm or 37

[1gabowles]

Did not know there different size forks for the 2005 R12RT

On the 05 RT 37mm, same as my 96 RT, which 96 manual says to use 470ml

ere'go I use 470ml for the 2005, correct ? Both have the same travel abt 120mm. gbowles@cfl.rr.com

[lkraus]

RepROM, 5th edition, 2/2007 says .45 liter per leg for the K26 0388 model R1200RT. 35mm fixed-tube outside diameter (which matches the measured diameter on my '06 RT). Since the 10 weight oil is used only for lubrication, not damping, 0.02l is not a significant difference.

 

 

[dirtrider]

Afternoon 1gabowles

 

There was a BMW service bulletin on the BMW 1200RT (about February of 2006) that said the early RepRom & early service manuals were incorrect & that the CORRECT oil quantity was 450Ml.

 

Caution: don't overfill the forks as that doesn't leave enough compression air space above the oil at full compression.

[Selden]

Translation: If there isn't enough air space above the oil at full compression, you could blow a seal.

 

That said, I find it hard to believe that 20 ml (2/3 of an ounce, or about 4 teaspoons) makes a significant difference. Barring an existing leak, I prefer measuring the distance from the top of the oil to the top of the tube before changing the oil, then using the recommended amount of oil, and re-measuring. Depending on how you have drained the tube, there could be some residual oil that would affect the level.

[Tom Forplay]

What oil spec have you used. Looking for amsoil. 

[dirtrider]

15 minutes ago, Tom Forplay said:

What oil spec have you used. Looking for amsoil. 

Evening Tom

 

Within reason it makes no difference as there is no valving or damping in the hexhead 1200RT forks (oil is JUST for fork lubrication).

 

But if want to be exact then the spec is 10 weight hydraulic oil (10 weight shock oil).