I decided to change the coolant on my R1200RS. Three years seems like a good interval for that, although the service schedule does not make any recommendation. My original intention was to follow the procedure in the Haynes manual, which is that you just drain the old stuff out, and then pour new coolant into the radiator, joggle the bike a bit, and then top it up. I was all set to start when I stumbled across a post on the Adventure Rider's forum from some guy who also tried the Haynes procedure on his R1200GS. He drained 1.5 liters out, but found he could only get 1 liter back in. It was about this time that my new BMW factory service manual DVD arrived. According to the BMW shop manual, you use the BMW special tool set to refill the coolant.
The BMW special tools for the coolant change costs a mere $550.00. I read the instructions about five times before I understood how this thing works. I then found YouTube videos of people using equivalent tools, such as something called Airlift, which I ordered for about $130.00 from Amazon. There are equivalent tools for less, some as low as $55.00, but the reviews indicate that about 20% of them are dead on arrival, whereas the Airlift is 100% five stars.
The gist of using this thing is you drain all the coolant, replace the drain plugs, and clamp the reservoir overflow tube (has to be airtight). You insert the Airlift into the radiator neck and tighten it. It fits in the R1200RS radiator neck without using any of the supplied adapters. You then connect it to (counter-intuitively) a compressor, which blows air past a venturi nozzle to create a vacuum in the cooling system.
Amazingly, it only takes about 3 seconds to get up to full vacuum. You then close a valve and disconnect the compressor, connect a supplied hose, primed with coolant, to a jug of coolant suspended above the radiator, and open the valve. The coolant is sucked into the cooling system, filling it almost completely, with no substantial airlocks. Pretty cool!
So with my new Airlift in hand, I was eager to complete this procedure. However, when I removed the drain plugs I found the right-side drain plug had been cross-threaded by whoever last installed it. Given that no-one has changed the coolant since this bike was new, it had to be the factory. The left-side plug is steel and costs $1.43, but the damaged right-side plug incorporates a "check-valve", is aluminum, and costs $26.00. Only the first couple of threads were damaged, both on the plug and in the cylinder. The plug is very lightweight and soft aluminum, so I was able to straighten up the threads pretty well with my thumbnail. However, try as I might, I could not get the plug to go back in. The start of the thread in the cylinder was too messed up. My friend Harry from the Chicago Region BMW club knows about these things, and recommended using a tapered thread tap to repair the threads. I ordered an M10 x 1.0 mm tapered tap from Grainger.
The cylinders of the 2014+ water-cooled boxers are part of the crankcases; unbelievably, they are not separate pieces. To replace the cylinder, you have to replace the crankcases with it. The minimum is the "base engine", which is US$5,800.00. I did not sleep well for a couple of nights while waiting for for the tap to arrive. I was worrying about what would happen if I completely destroyed the thread in the cylinder. I could insert a helicoil, but that would probably not work as it does not provide a good sealing surface for the plug. Then I discovered TIME-SERT, which is a helicoil competitor. Rather than a wire coil, TIME-SERT is a solid-walled hollow plug that has a flat-faced flange on the outer end, and would probably do the job perfectly. The stainless steel version of the M10 x 1.0 x 9 mm plug costs about $4.00 each, but the M10 x 1.0 installation kit is $110.00. With that possibility in my back pocket if rescuing the thread with the tapered tap failed, I slept a little better.
When the tapered tap arrived, I followed Harry's advice. Using a T-shaped tap handle with the cross piece removed, I gently worked the tap up into the thread as far as I could without turning it. When I was certain I had the tap's threads mated properly with the cylinder thread, I turned the tap with my fingers. I felt something give, and was then able, with just my fingers, to screw the tap in a couple of turns with little resistance. I unscrewed it from the thread and a small piece of aluminum thread about a millimeter square came out with it.
I put the radiator cap on and blew compressed air in the other plug hole to blow any fragments out of the repaired thread. I put a new aluminum crush washer on the plug and held my breath. It went in with very little fuss, and I torqued it to 4.5 Nm (5 Nm recommended). I was then, over a month after I started, able to complete the rest of what should have been a 1 hour job. The Airlift worked like a charm to fill the radiator.
The BMW special tools for the coolant change costs a mere $550.00. I read the instructions about five times before I understood how this thing works. I then found YouTube videos of people using equivalent tools, such as something called Airlift, which I ordered for about $130.00 from Amazon. There are equivalent tools for less, some as low as $55.00, but the reviews indicate that about 20% of them are dead on arrival, whereas the Airlift is 100% five stars.
The gist of using this thing is you drain all the coolant, replace the drain plugs, and clamp the reservoir overflow tube (has to be airtight). You insert the Airlift into the radiator neck and tighten it. It fits in the R1200RS radiator neck without using any of the supplied adapters. You then connect it to (counter-intuitively) a compressor, which blows air past a venturi nozzle to create a vacuum in the cooling system.
Amazingly, it only takes about 3 seconds to get up to full vacuum. You then close a valve and disconnect the compressor, connect a supplied hose, primed with coolant, to a jug of coolant suspended above the radiator, and open the valve. The coolant is sucked into the cooling system, filling it almost completely, with no substantial airlocks. Pretty cool!
So with my new Airlift in hand, I was eager to complete this procedure. However, when I removed the drain plugs I found the right-side drain plug had been cross-threaded by whoever last installed it. Given that no-one has changed the coolant since this bike was new, it had to be the factory. The left-side plug is steel and costs $1.43, but the damaged right-side plug incorporates a "check-valve", is aluminum, and costs $26.00. Only the first couple of threads were damaged, both on the plug and in the cylinder. The plug is very lightweight and soft aluminum, so I was able to straighten up the threads pretty well with my thumbnail. However, try as I might, I could not get the plug to go back in. The start of the thread in the cylinder was too messed up. My friend Harry from the Chicago Region BMW club knows about these things, and recommended using a tapered thread tap to repair the threads. I ordered an M10 x 1.0 mm tapered tap from Grainger.
The cylinders of the 2014+ water-cooled boxers are part of the crankcases; unbelievably, they are not separate pieces. To replace the cylinder, you have to replace the crankcases with it. The minimum is the "base engine", which is US$5,800.00. I did not sleep well for a couple of nights while waiting for for the tap to arrive. I was worrying about what would happen if I completely destroyed the thread in the cylinder. I could insert a helicoil, but that would probably not work as it does not provide a good sealing surface for the plug. Then I discovered TIME-SERT, which is a helicoil competitor. Rather than a wire coil, TIME-SERT is a solid-walled hollow plug that has a flat-faced flange on the outer end, and would probably do the job perfectly. The stainless steel version of the M10 x 1.0 x 9 mm plug costs about $4.00 each, but the M10 x 1.0 installation kit is $110.00. With that possibility in my back pocket if rescuing the thread with the tapered tap failed, I slept a little better.
When the tapered tap arrived, I followed Harry's advice. Using a T-shaped tap handle with the cross piece removed, I gently worked the tap up into the thread as far as I could without turning it. When I was certain I had the tap's threads mated properly with the cylinder thread, I turned the tap with my fingers. I felt something give, and was then able, with just my fingers, to screw the tap in a couple of turns with little resistance. I unscrewed it from the thread and a small piece of aluminum thread about a millimeter square came out with it.
I put the radiator cap on and blew compressed air in the other plug hole to blow any fragments out of the repaired thread. I put a new aluminum crush washer on the plug and held my breath. It went in with very little fuss, and I torqued it to 4.5 Nm (5 Nm recommended). I was then, over a month after I started, able to complete the rest of what should have been a 1 hour job. The Airlift worked like a charm to fill the radiator.
Good think its is a Canadian-made tool. 
