BMW R1150R Wheel Circuit Brake Fluid Reservoir Gadget

I just completed a complete brake fluid change and a valve adjustment the 2004 BMW R1150R this weekend, and I have to say, it wasn't as mystical as I thought. Have a look at the R1150R Tech Info site for the DIY details. I have never attempted working on a motorcycle before, much less a BMW. But a bit of common sense, the basic tools, and a few hours of spare time for each is all that's needed.


The only semi-mystical part was to figure out a way to create a funnel adapter to hold fresh brake fluid to feed into the wheel circuit reservoir while bleeding the system. BMW will happily sell you one for $200, or you can build yourself the "Mini-Stan" pictured here for about $30.

My only issue with the Mini Stan was I had to order the threaded part to mate with the wheel circuit reservoir, and I'm far too impatient when my mind is set on getting something done that day. So I went to Ace Hardware and improvised.

The solution was pretty simple - a small rubber drain plug and a 1-pint funnel. Here's the finished product. -->



Just bore out the center of the plug with a drill, ram the funnel in, and trim down the skinny end until it seats firmly in the wheel circuit opening. Works like a charm, and only $5!!





The rig in action: -->











That said, flushing out the brake calipers and the wheel circuits was a pretty easy process, just follow the directions available at R1150R Tech Info. Flushing out the control circuits took a bit more time as was a bit more of a messy process for one reason - when you pump the brakes, even slowly, brake fluid will try and squirt back up through the blow hole in the bottom of the reservoir. It's hard to explain, but once you see a stream of brake fluid fly out of your front control reservoir, you'll figure it out pretty quick. I read that one remedy was to place a clean utility knife blade over the blow hole to prevent splashback, and dig it out when you are done.

And again, the valve adjustment was pretty straight forward procedure and just requires a little patience and time to get a feel for it. I don't think I got my valves spot-perfect matched to each other, but nonetheless I could feel how much smoother the cold engine was operating at idle.

Happy Tinkering!!