Tuesday, 31 July 2012 [71,708 miles]
Charger pig-tail
This morning I called several BMW shops but none had the cam speed sensor in stock. SF BMW said they’d have one by Thursday if I wanted to order one. Order placed.
Yesterday I put the battery on the charger as I was cleaning up. I left the battery charging over night. I’m going to be using battery juice while flushing the front and rear wheel circuits. This image shows the pig-tail I used for battery charging. It goes through my Fuzeblock but is unswitched. The connector with the yellow tape is a switched lead for my heated gear.
Left front caliper
Original pads
4.36mm
These are the original brake rotors and pads. There is lots of life left in both. The right side looks and measures almost identical to the left. Minimum disk thickness is 4.0mm. Original was around 4.5mm. I’ve used less than half of the available thickness.
Retracted pistons
ABS reservoir
Brake fluid overflow
Note to self. Before retracting caliper pistons suck out the excess fluid from the ABS reservoir AND install the bleed funnel. If you don’t the fluid will come out the overflow tube all over your center stand and garage floor.
Anti-squeal
keep pistons retracted
Flush
I cleaned up both sets of pads with brake cleaner and an old tooth brush. Once the brake cleaner had dried I sprayed the back of the pads with a sticky anti-squeal product. I gave the pads 10 minutes for the sticky stuff to set then put them back in the calipers and used some wood shims to keep the pistons retracted while flushing the system. I flushed the left side and then the right side.
Now the control circuit
Control circuit flush
After flushing the wheel circuits I emptied the handlebar reservoir and hooked up the bleed tools to flush the control circuit. I filled the reservoir then started the flush the old fashioned way: pump, pump, pump, squeeze the lever while loosening the bleed nipple then tighten the bleed nipple before the lever runs out of room to move.
The one-way valve I use on my bleed tube gives me a safety margin should I run out of lever room before closing the valve.
Clutch fluid
My clutch feels fine but I can see the results of clutch wear every service. As the clutch gets thinner the system needs less fluid in the slave cylinder so it migrates to the master cylinder. The level was again slightly above the max mark on the reservoir. I dipped the corner of a clean paper towel into the reservoir to draw off a little fluid. When done I buttoned up the reservoir. The reservoir cap requires a special tool to remove… I made mine from a bent piece of wire coat hanger.
Rear pads
Replacement pads
Old fluid
The rear pads looked better in the picture than they did live. There were a few more thousand miles left on the pads but why screw around. I threw them away and installed a 1/2 used set that I took off the bike when I replaced the rotor about 22K miles ago.
The rear rotor is now 4.96 mm thick. This rotor is wearing much slower than the stock, but the stock pads are now wearing a bit faster.
This time I was smart and not only drained fluid from the ABS reservoir but also installed the fill funnel before retracting the rear caliper pistons. What you see in the third picture is the old fluid that had been pushed into the ABS reservoir. I sucked it out and filled with fresh DOT 4 before starting the flush.
Brake flush tools
Rear control reservoir
The first pictures shows my brake flush tools… a catch bottle, the bleed hose with one way valve, and a syringe with thin tube that I use to suck old fluid out of reservoirs. The spray bottle is filled with water to quickly dilute any possible spillage.
After finishing the rear wheel circuit I flushed the control circuit. That almost finishes the brake portion of the service. I need to top off the rear ABS reservoir after putting the caliper back on the bike and seating the pads. Right now the caliper is hanging from the pannier rack with a cable tie so it will be out of the way when changing FD fluid. I also need to hook up the GS-911 and do the ABS bleed test.
More tomorrow. Before putting everything away I oiled up the Uni air filter. I’m litting it sit over night to let excess oil to drain before installing it into the bike.