Coolant Leek

[yfzrider310]

Alright so after riding my yfz today I parked it in the garage. The next morning I go out there and there coolant on the ground (not that much.) But ever since then its slowing leeks out. I can see it coming out of a tube on the bottom of the motor that I suspect is the overflow tube. Since I dont have the manual I cant tell what the line is. Any help would be great!

The black tube that is like half inch fat on the bottom end of the motor is the crank case breather tube which oil can come out some times. The radiator fluid rez is in the back of the quad on the sub frame and has a lil tube that always ends up leaking a little when you drive.

If its leaking under the motor its probably your watter pump seal. Its a commen problume on yz and yfz motors. Nothing to really be conserned about. The seal usualy expands and stops leaking once the motor heats up.

[jshtex]

Apparently rather than fixing the water pump leaking problems our yfz's have in 06 (which he has?) they ran a small rubber hose from the bottom of the water pump to back around the swingarm.

My guess is that is where the coolant leak is. On the older quads it just dumps out he weep hole on the bottom of the water pump.

If thats what it is, then to fix it you will have to replace at the very least the seals in the water pump.

When I do it, I replace both seals, the impellar shaft, and the impellar shaft bearing. The "right" way to do this involves pulling the side case off the motor so you can get a wrench on the back side of the impellar shaft to hold it while you remove the impellar.

Some guys though will just bust the impellar off the shaft with a wrench and then only replace the outer seal. Not me though.

By the way, on the older quads like my 04 yamaha actually put one of the seals in backwards from the factory so if yours are wrong and you put them back in the same way they came out it will only be a matter of time. The flat side of the two seals should face each other in the middle.

[yfzrider310]

Sounds like an awful lot of work just to fix a little leak. I dont know it just decided to stop leaking but if it starts again Ill keep you informed. Thanks for the information and if it starts again Ill try and do what you said to do.

[jshtex]

It's not too bad, I can do it in less than half an hour now.

Sure you can ride it with a leak, but just keep an eye on the coolant level.

[yfzrider310]

you can split the cases in a half hour!!! Your coming over to my house. :devil:

[yfzrider310]

you can split the cases in a half hour!!! Your coming over to my house. :devil:

[jshtex]

You don't split the cases. You do have to take the side cover off that the clutch cover bolts onto. If you tip the bike up on the other two wheels you don't even have to drain the oil to do this.

I promise it isn't that big a deal.

[yfzrider310]

O thats way easier. Lol. I was like you must be amazing if you can do that job that fast. Yea now I think I can do it.:D

[jshtex]

I spent around a week working on the thing when I "split the cases". It didn't actually take that long in real time but I did take my time doing it. I had to do this because of a broken chain busting the case. While I was in there I went ahead and replaced all the bearings in the case and put in a WR crank.

[slwbanshee]

jshtex , thank for the info my 04 yfz has been leaking out of the weep hole on the bottom . I hope my seals are just bad

[yfzrider45]

Hey guys, mynes the 04 with the "weephole".....It was leakin out of the weephole so i changed the seals and the bearing and the leaking stopped.....If you see grooves on your impeller shaft then you need one of those!!!!! And since i was there i'd figure i'd put a mod-quad hi-flow impeller.....PM me if anyone needs more details on it!!