Got home from a ride yesterday and noticed coolant running out from under my 4-wheeler. It is a 99 Polaris Explorer 400. Got to looking and taking off some plastic and the coolant is coming out of the weep hole inside the water pump. I have never worked on this kind of problem before and would like all the advice I can get. It looks like you have to pull off the flywheel cover, flywheel, and half the motor case to get to it. Are there any special tools or tips I need to know about. Thanks in Advance!!!!
Ronster Monster...

 

It does take a tool or two to do this . Do you have a automotive style puller? (for harmonic balancers or steering wheels ? )

As far as parts go , you will need to spend about $25.00 . Write back on here , I'll give you a hand .

This isn't to bad a job if you have patience and a few tools . If not , take it to a good dealer . I would think a dealer would charge about $150 to $250 to do it .

 

I don't know if you have exactly the same problem I did, but I took my 01SPHO mudding. With only 270 miles on it, it started to leak antifreeze. Evidently a mechanical seal went out on the water pump. I also know of someone else who had the same thing happen to his sportsman. He bumped into a person who workes on the motors up here in Wisconsin and evidently Polaris knows that this is a problem and is in the works of fixing it. The guy told my buddy how to fix the problem so it doesn't happen again, but he forgot what exactly the parts were to fix the problem. All I can say is that mud and dirt somehow screws up the pump commponents and blows the seal. As for telling you how to get it fixed, your going to have to take it up the butt and fix it. As for me, I got the warrenty to cover it.

 

It happened to me too. The problem is the overflow bottle cap; it has a small hole in it to allow it to breathe. When driving through mud holes the engine is cooled off causing the coolant to contract therefore drawing coolant from the overflow bottle back into the engine. Unfortunately the bottle is submerged in muddy water and the muddy water gets sucked into the overflow bottle. It doesn't take a rocket scientist to figure out where the muddy sediment goes form there.
To replace the mechanical seal you will need a special tool to remove the old one and another tool to install the new one. The removal tool is very important cos if you pull the seal out at an angle you will damage the pump shaft and to replace it the crankcase has to be split. The installation tool can be made up using a couple of pipe fittings.

To prevent this particular problem from happening drill out that small hole and install a tube fitting that will accept plastic tubing then run the tubing to a high point on the quad to keep it away from the muddy water. Simple fix but it works.

Another point that is worth mentioning is never use auto coolant because it is high in silicate and that can wipe out the mechanical seal too. Always use antifreeze designed for your quad.

 

I just want to thank everyone for all their inputs. Every bit of information has been helpful. I haven't been able to locate any aftermarket manuals for a 99 Polaris explorer 400 2-stroke and the service manual I looked at that is put out by Polaris is a joke! If anyone knows where you can purchase a good service manual for my year model and make of Polaris is would be Greatly appreciated. Thanks Again!

 

If you are interested I can scan a couple of pages from my Polaris manual that show the removal and installation of the mechanical seal. The illustrations and explanations are quite good. Let me know.

 

My buddie has a 500 sportsman and the waterpump is leaking out the little hole,could you scan that page for me?

 

profish00, sorry to have to tell you this but my scanner software quit working and haven't been able to fix it. Maybe someone else on the forum can help.
To add to my original post, another and more significant reason for the wp seal to fail is the weep hole itself. Muddy water enters the weep hole and contaminates the seal from the outside. The fix is to cut a piece of 1/4" (preferably stainless steel) tubing approx 3/4" long, taper one end to enable it to fit into the weep hole. Place a little epoxy glue on the newly made taper, insert it into the weep hole and tap it in until snug. Once the glue is set install a piece of rubber tubing over the newly installed tub stub and route it up approx 3" and let the end hang down a couple of inches.
I hope this makes sense to you.

 

Traildog

It sounds like I have a similar problem to others on this post. I have a 2000 Polaris 400 Xplorer, which leaks water out of the weep hole down by the water pump. I was wondering which seals may need to be replaced, and how difficult the job might be.

Thanks.