BMW K1200, K1300, and K1600 Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
1,819 Posts
Internal flush? Never been a requirement for me.In over 170K I have never noticed any deposits.Mind you I replace the coolant every year or two with some brand to BMW specs.No nitrites,No phosphates and low sillicates is the spec.

External flush? As in dismount the rads and clean the fins from sand/bug crap and at one time road tar?I have to see through them fins,not take a guess.:glasses Pretty well every year or 20-25K.
 

·
Registered
Joined
·
107 Posts
Discussion Starter #3
Makes sense.

The dealership has never done the internal flush.

I was having a problem with coolant burping after a hot ride.

Replaced the radiator cap and hasn't happened since.

The old cap did not have any visible defects though.
 

·
Registered
Joined
·
529 Posts
...
Replaced the radiator cap and hasn't happened since.

The old cap did not have any visible defects though.
Forgot to mention the burping was coming from the reservoir overflow tube.
These symptoms are fairly common with time / age on the K1200RS/LT , it clearly means the radiator cap is/was defective.

By design, the K1200RS/LT have higher pressure rating radiator cap (21 PSI / 1.5 bar) compare to most Japanese water-cooled motorcycles (16 to 18 PSI). This value of 1.5 is stamped on top of the cap, so make sure this is what you are being offered as a replacement.

ANOTHER IMPORTANT POINT: although the expansion tank (under seat) has a MAX mark, I would suggest to only fill about 1/4 inch above MIN when ENGINE IS COLD and no more. The size of the tank combined with coolant expansion is such that it will overflow when HOT if you use the MAX level. I have tested this on many K1200RS in good mechanical shape with same result...
 

Attachments

·
Registered
Joined
·
107 Posts
Discussion Starter #7
These symptoms are fairly common with time / age on the K1200RS/LT , it clearly means the radiator cap is/was defective.
Good to know.

I think the replacement was based on your previous advice.

Thanks again.
 
1 - 7 of 7 Posts
Top