the "oil seal" that sits behind the impeller in your water pump can ruin your day. your motor too!

i had started my bike up in the shop, warmed it up good and turned it off. well, coolant (i should say - distilled water and waterwetter) came out of my skid plate. i thought it might be a little from the overflow tube. i thought nothing of it and put a towel under it and closed the shop. a week later i went to pick up the towel. it was SOAKED! huh? this is really odd. so i open the radiator. empty. HUH!

so i pour some coolant in. it starts flowing out the skid plate. WHOA! that can't be the puke tube. so i grab the 12mm and 10mm sockets and start pulling the gyt-r right guard. the coolant is coming out some small hole under the water pump. OH! it is a weep hole. ah ha! i get a jug and open the water pump drain. out comes about 1 cup. that was all that was left. i pull the 4 bolts of the water pump cover and the impeller. a little compressed air shows the seal is way gone. i pop it out with a small screw driver.

the part number is 93109-11073-00 for this oil seal.
partsfish showed 2.82, yot 2.92. my local megastore gouger -> 3.64, the small shop that takes longer to get -> 3.02. it took a week. 7 full days for the local to get it in. i didn't want to pay the $7 in shipping for pf or yot.

it taps in easy with a 17mm socket.

here is the important part:
if this seal fails. you are done. i mean big time done.
if you are in an offroad race, your motor is gonna cook (ie, new bottom end, new top end -> the crank up).
if you are in a mx/sx race, having one in your bag *should* let you finish the day if it fails during a 5 lap moto.
the trick is noticing it leak. if you never see it leak, you will cook your motor so fast it will amaze you.
so, buy one or two and thow them in a gear bag. a cheap way to prevent a day at the track or vacation from being a catastrophy.

steve

Thanks for the heads up! Glad you caught it as you did before any damage done!

Did you replace both oil seals or just the front one or just the back one?

I dnf'd and enduro last year when my seal went. There are actually two seals in there. There is an oil seal on the inside of the case and one on the water pump side. Its designed this way so that if one fails then the water drains out of the bike instead of into the engine which could do major damage. I figured that mine had actually gone bad from the previous enduro when I put a hole in my radiator and really cooked my bike. I had the fluid dripping just like Sunhruh did but I figured it was nothing and ran the next enduro where it failed. Now I keep two in my tool box and if I ever really overheat the engine from breaking a radiator I automatically replace the seal. It takes 10 minutes and is great piece of mind. All you need to do is replace the front seal.

BikeDestroyer has a good question. The weep hole may have actually saved you from more engine damage. It allows the coolant to drain out before entering the oil side of the motor. And I assume you're talking about motor damage due to no coolant. This may make a good case for WR owners to retain their coolant reservoir.

i replaced just the front one (ie the one that is in the coolant). can the back one be done changed via the pump cover off (ie not pull the case)?

and yes, because of coolant loss.

It looks like to replace the back one all you have to do is pull the crank case cover. I just had to do that a week ago to replace the gasket and it's really simple. I was just curious as to if you had to replace both or not. Thanks for the heads up and since they are so cheap I'll be ordering a couple and keeping them in my toolbox.

No, just replace the front one.