Water Pump Seal

Dailyrider has been replacing his water pump seal at 50K intervals after it failed on him at some point.

We are still trying to find his writeup but with people approaching close to 50K miles its a service worth thinking about to reduce the chances of having oil mixing with coolant!!

Snowdog, you should have nothing to worry about for another season. I changed my original waterpump seals at 85,400 miles, which was about 5,000 more than I should have let them go. I was getting a tiny bit of coolant in the oil for about 5,000 miles. I would recommend changing them at 50,000 miles, that's the schedule I'll be working on from now on. I'll change mine at 136,000, because that will be my next oil change, that will make 51,000 miles on these seals, I'm at 133,000+ now. I didn't find my pump shaft to be worn at all, so hopefully yours will be the same, both seals are only about 8 bucks. I replaced the shift shaft and clutch shaft seal as they recommend in the manual, but probably won't do it this time. The new clutch shaft seal weeps just as much as the original and the shift shaft seal has never weeped at all. The job is really pretty easy to do, make sure you leave a little space between the seals, so that if you do get a coolant leak, it won't go into the crankcase. The factory had jammed the seals together on mine, so no coolant could get out of the weep hole, went into the crankcase instead. Be sure to jam some real heavy grease in the balls of the clutch throwout bearing, so that the release segment will stay in place to mesh with the clutch shaft teeth. The teeth part of the clutch release segment is the lightest side, so it always trys to face up but that won't mesh with the clutch shaft teeth!! Anyway, have fun. The CS is undoubtedly the best all around bike ever made, I'm sure of it!!!!!

RkyMtnMan gives the following instructions

- draining oil & coolant
- disconnecting the clutch cable and removing the little fork/arm
- removing the foot peg
- removing the shifter lever
- disconnecting the exhaust from the head and loosening the clamp by the passenger peg
- disconnecting the oil line at the bottom only
- removing 10 side cover bolts, plus two from the starter
- removing and replacing the cover, after fixing the gasket
- buttoning it all back up and replacing fluids

Removing/replacing the seals and other water pump parts (impeller, shaft, drive gears) only took about 15 minutes once the cover was off. And it took that long only because I ALSO replaced the clutch shaft and shifter shaft seals at the same time.

I did the whole job in a motel parking lot, using only my "on the road" tool kit.

In short, I think the "fear factor" is greater than the job actually merits. Don't be afraid of this one.


Here is a parts list including clutch and shifter shaft seals(might as well do those too while you are in there)

  • 115 176 52905, Qty 2 — plastic drive gears
  • 115 123 43451, Qty 1 — water pump kit (impeller, shaft, seals)
  • 212 123 43259, Qty 1 — clutch shaft seal
  • 111 423 43038, Qty 1 — shifter shaft seal
  • 111 477 06498, Qty 1 — side cover gasket
  • 071 199 63276, Qty 2 — oil line banjo bolt crush washer
  • 111 423 43240, Qty 1 — water pump drain bolt crush washer
  • three quarts oil
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