I'm weeping??

My buddies 98 400 did the same exact thing, but water was gushing out that hole. Tried replacing the gasket, but ended up replacing whole waterpump.

The same thing happened to my 99 YZ400. I replaced the whole pump and seals since the impeller shaft had a lot of build up on it and it would have torn the new seals to shreds. It is pretty easy to do.

One word of caution, be careful with the banjo bolt in the oil feeder line. It is very easy to strip out the threads in the crank case cover. Make sure the threads are clean and the bolt is not cross threaded. (Don't ask how I know this

:) )

It is a simple <$2 fix.

do yourself a favor and get it fixed asap.

It is a way to let you know that the seal is wearing out. This lets u fix it b4 water passes into your crank case and mixes with your oil. I had no clue what it was or how to fix it and it took me about 20 min from start to finish. Be very careful how you push the new seal in. I used a socket that just BARELY fit into the hole and drove in the seal VERY squarely and tapped easily.

I used a small flat screwdriver to very gently pry out.

Really is very simple. :)

hi fellas,

I'm leaking coolant at a very slow pace from the weep hole in the botom of the water pump cover. What does this mean? Any help would be much appreciated.


Sounds like a bad waterpump seal to me. I had that happen on my KX250 and a previous 4-wheeler I used to own. You will have to completely disassemble the waterpump and replace the seal from the back side of that righthand crankcase. It is easier than it sounds but follow the directions in your manual. Good luck and sorry to hear about the leak!! Frank :)

Hey Rock hucker (or anybody)

Can you please refer to the ownre's manual on page 4-46 and let me know which seal you are talking about. is it #15-oil seal 1 or #16-oil seal 2?? Thanks for your effort.


There are actually two seals at teh water pump. While you're in there, I'd replace them both. In fact, I have my 450 torn down to replace the counterbalancer key (it was VERY loose) and the water pump parts. Mine is a '98 that has all the original water pump parts so I'm replacing the shaft, the bearing and both seals.

I only replaced the outer one AND the gasket which is rubber. and mine has been fine. But like MX says since you are in there anyway you may want to replace both. The outer one is the one that is the last line of defense for H2o in your oil so it is obviously the most important! :D

I think the gasket and seal were around 5bucks w/disc.???? :)

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now