Resurrections, KLR250 Part 5: Two Steps Back

In Part 4 of the KLR Chronicles I managed to damage the water pump oil seal. Never one to stand pat, in Part 5 I damaged the new water pump ceramic seal. It wasn’t easy and I’m still not sure how it happened.

After cleaning off the old gasket material stuck to the clutch cover I managed to get the new oil seal installed without drama. Next I used a suitable sized socket to pound the new ceramic seal into the water pump housing. This all went well and as such was probably where I broke the seal.

The clutch cover has two locating dowels but the gasket was sort of floppy and would slip out of place when I tried to install the cover. I ran down to NAPA and picked up a can of spray gasket High Tack goo and used that to hold the gasket while I messed with the cover.

Reassembling the mess was easy from then on and I filled the radiator with new coolant expecting success. I took the bike for a short ride and dammed if the water pump wasn’t leaking worse than when I started. Resigned to never getting the bike going I removed the water pump cover and water pump impeller. I thought maybe the impeller o-ring was the culprit so dismantled the cover and replaced the o-ring and tried again. It still leaked. Dismantling the pump for third time was when I found the crack.

The ceramic seal is a multi part extravaganza consisting of a flat seal area, a spring, a rubber bellows and the metal ring part that fits into the housing. I tried pulling the ceramic part off but it just crumbled. It took a bit of tugging to remove the bellows and spring from the metal. And then I remembered that when I removed the old seal the spring, bellows and seal fell out into my hand. This made me think that the old seal wasn’t leaking at the ceramic interface and, in fact, was leaking between the bellows and the metal ring part.

If you’ve followed my mechanical exploits you can guess what happens next. I cleaned the metal ring (still stuck in the housing) and the old seal bellows. Then I blobbed black RTV silicone on the ring and glued the old seal/spring/bellows into the new ring.

And it worked! The water pump no longer leaked. This kind of repair is not the sort of thing you want to rely on 50 miles out into the desert so I’ll have to order yet another water pump seal. This time I’ve got an idea and will try something different to remove the metal ring. I hope to not pull the clutch cover again. We will see.

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