Swapping in fresh coolant and heard a brief mention of a preferred drain location other than the large coolant hose. The speaker was not specific but said it was in the same area as where the main coolant hose connects to the block. I'm reluctant to take the main hose off because they are more prone to leaks. Does anyone know of this alternate drain location and perhaps have some images to guide me? Also, do I need to drain the system at more than one location? Thanks as always for the help.
WayFast
2001 K-RS Coolant Drain Location
1 reading
There are 2 methods commonly used to drain the old coolant on these K1200RS-GT and K1200LT. Believe it or not... even BMW is confused as they say to use method 1 below in their K1200RS shop manual. On the other hand, they say to use method 2 in their K1200LT shop manual. In the CLYMER shop manual for K1200RS-LT, they basically repeat / copy from the BMW books: if you have a K1200RS use the hose - if you have a K1200LT remove the coolant temp sensor (more on this below).
To me this is non sense as the engines are the same on both. Of course the K1200RS has an added flange for oil cooler hoses between engine block and oil-water pump, but this does not affect the amount of coolant or where it flows. This K1200RS oil cooler flange only affect the total amount of oil entering / circulating in the system.
Method 1: remove the large hose connecting the right radiator TO the the water pump inlet below. Be prepared with large container as coolant will rush out very fast. Only issue with this method is the fact it leaves about 1/2 cup that stays in the pump.
Method 2: Disconnect wire from engine coolant sensor located below water-oil pump assy. Then remove / unscrew this temp sensor (this feeds only the temp gauge on dash - not the engine computer). This will drain more slowly than method 1 above as the size of the hole / threads is only 10 mm (the wrench needed is 14 mm). See photo below taken on a K1200LT - same water-oil pump but no hoses for oil cooler. IF you use this method , be very careful as there has been a few cases (over last 15 years in many forums) where the sensor threads would be seized in the water pump assembly because of corrosion. If previous owner / or previous mechanic was always using method 1 instead, over time this sensor will seize there when not moved.
Using either method, it is important to remove the radiator cap FIRST to help the liquid go out. It has been my experience that the system is difficult to fill completely unless you:
(A) fill slowly when parked on center stand
(B) massage the lower hose connecting both radiator as you approach being full visually in the cap hole
(C) when full , close the cap properly and run the engine once on center stand until the fans will start - let it cool down overnight.
(D) after the engine has cooled down to room temperature, open the cap again (on center stand) and fill just enough to be able to install cap without overflowing out of cap.
(E) When engine is cold, set overflow tank under seat between MIN and MAX. I avoid filling to MAX when cold as the overflow tank level can go up as much as 1 inch when engine is very hot (after fans start).
Personally I have always used method 1 for emptying the coolant since new (about every 3 years on average). It is only a few years later that I learned about method 2 (when the CLYMER manual was published). Around 2010 when I saw a few issues on K1200LT forums with the sensor being seized and causing damage to water pump, I became convinced I would never remove the sensor unless it was defective.
I would rather buy a new connecting coolant hose that may get a bit worn by the pulling / removal over 20 years THAN having to deal with a sensor that breaks inside the water-oil pump assembly. I have seen pictures of the damage / corrosion on the K1200LT forum - it was not pretty...
![Image]()
To me this is non sense as the engines are the same on both. Of course the K1200RS has an added flange for oil cooler hoses between engine block and oil-water pump, but this does not affect the amount of coolant or where it flows. This K1200RS oil cooler flange only affect the total amount of oil entering / circulating in the system.
Method 1: remove the large hose connecting the right radiator TO the the water pump inlet below. Be prepared with large container as coolant will rush out very fast. Only issue with this method is the fact it leaves about 1/2 cup that stays in the pump.
Method 2: Disconnect wire from engine coolant sensor located below water-oil pump assy. Then remove / unscrew this temp sensor (this feeds only the temp gauge on dash - not the engine computer). This will drain more slowly than method 1 above as the size of the hole / threads is only 10 mm (the wrench needed is 14 mm). See photo below taken on a K1200LT - same water-oil pump but no hoses for oil cooler. IF you use this method , be very careful as there has been a few cases (over last 15 years in many forums) where the sensor threads would be seized in the water pump assembly because of corrosion. If previous owner / or previous mechanic was always using method 1 instead, over time this sensor will seize there when not moved.
Using either method, it is important to remove the radiator cap FIRST to help the liquid go out. It has been my experience that the system is difficult to fill completely unless you:
(A) fill slowly when parked on center stand
(B) massage the lower hose connecting both radiator as you approach being full visually in the cap hole
(C) when full , close the cap properly and run the engine once on center stand until the fans will start - let it cool down overnight.
(D) after the engine has cooled down to room temperature, open the cap again (on center stand) and fill just enough to be able to install cap without overflowing out of cap.
(E) When engine is cold, set overflow tank under seat between MIN and MAX. I avoid filling to MAX when cold as the overflow tank level can go up as much as 1 inch when engine is very hot (after fans start).
Personally I have always used method 1 for emptying the coolant since new (about every 3 years on average). It is only a few years later that I learned about method 2 (when the CLYMER manual was published). Around 2010 when I saw a few issues on K1200LT forums with the sensor being seized and causing damage to water pump, I became convinced I would never remove the sensor unless it was defective.
I would rather buy a new connecting coolant hose that may get a bit worn by the pulling / removal over 20 years THAN having to deal with a sensor that breaks inside the water-oil pump assembly. I have seen pictures of the damage / corrosion on the K1200LT forum - it was not pretty...
I like the hose method.But make sure it is repositioned correctly, a slight twist at the clamp can bring the hose forward a touch and it may contact the belly pan fastener/clip and wear.Screw should be a short one.
It may not look like it contacts at rest on the stand but riding at speed there can be enough pressure to push the fastener/clip against the hose.
It may not look like it contacts at rest on the stand but riding at speed there can be enough pressure to push the fastener/clip against the hose.
That angled edge of the clip was probably the culprit? I remember rounding it off on the bench grinder as an extra caution.At 21psi cooling system pressure them hoses most probably expand some.
1994 K1100rs. I replaced my temp sensor that communicates with the gauge. Now it seeps coolant. The sensor that I removed did not have a washer. The new one does. Now it leaks. Should I remove the washer or is there something I was supposed to put on the sensor threads to prevent this?
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