I've searched through the forums and found a thread about this but there was no follow-up on it...

I have a '98 Scrambler 400 and it just started leaking coolant from the weep hole on the right side of the case slightly forward and below the recoil housing and water pump. You really have to get down on your knees and get your head in there to see it.

I've read that it means the seal behind the water pump is bad and it is there to prevent the coolant from pooling inside the case. Kind of the same idea as vehicle water pumps when they go bad.

My question is, has anyone done this fix and if so, what do I need to buy? Any special tools? Does the case need to be split? Thanks a bunch in advance.

 

Recoil and flywheel and stator have to be removed(stator can hang out of the way) inner case has to be removed(not crank case,has three cases total),depending on machine,if coolant neck on case is hard to remove from frame,top motor mount can be loosened to allow removal. The water pump is behind the cover with 2 seals and a bearing,plus gasket. Plus,check counter balance end(that drives water pump) for scoring,damage. Plus 10 mm bolt on top of head has to be bled when coolant added or over heating can happen from air bubbles. Manual is recommended If you do it your self. OPT

 

I'm in the middle of a rebuild on my 99 xplorer 400. I had water and counterbalancer oil mixing. Take your time and get a manual. The shaft for the waterpump (where the bearing and two seals are) was corroded and let the counterbalancer oil and radiator fluid mix. There is also a gasket that could possibly be leaking on the water pump. There are two special tools that you'll need. One is to remove the nut behind the flywheel and stator, which is a left handed nut and the other is to remove the counterbalancer. The stator assembly has to be removed before the nut comes off. Hopefully, you won't have to remove the counterbalancer or replace it. The counterbalancer is very expensive. Like $380. I wound up pulling the motor out of the quad. I had the cylinder resized and installed a new piston. If you pull the motor you will have to pull the clutch will also require a special tool. If I remember correctly you can use a 3/4 inch fine thread bolt that is 9 inches long to remove the clutch.

The tool for the nut removal (behind stator)I purchased here: Slotted Nut Socket

I also have a web address for counterbalancer pulling tool. I'm on the road right now and don't have it with me. When I get home this evening I'll send it to you.

If you have the time, all of the info that I have received for my rebuild has been thru this forum. It just takes time to sift thru it all. Use the search function of the forum. I'm not a mechanic but I'm taking my time and doing quite a bit of research. Hope this helps and Good Luck

 

Can anyone tell if the flywheel bolt is right or left handed thread? I am having a bitch of time trying to get the nut off.

 

Counter clockwise to remove.. Spray a little PB Blaster plus let it seep in if it can,plus I've had some that I used both penetrant and a little heat from a propane torch to help loosen rusted nuts. Plus if you don't have an impact it can be a little tough.

 

Thank you very much! I thought it was right handed but couldn't break it loose with my impact and did not want to bust it. I ended up with a BFBB to get it loose. Now, on to see why the coolant is coming out the crankcase breather tube. Hope it is just a seal. You a very valuable asset to this forum, plwase keep up the good work.

 

What is the secret to getting the case that is in front of the pump off. Does the stator have to be removed or disconnected. i have it loose but cannot remove it.

 

Stator plate has to be removed. Be sure to mark the plate and the case. Some have a stator plate mark and case mark,but make sure you know exactly where it goes back. Can affect timing if you're far off. All 400's are basically the same. Critical on water pump seals and bearing installation in the w/p housing.You have to make sure you don't block the hole in the housing. Many forget to do this. This is where the manual really helps and explains on this and explains step by step.http://www.download-repair-manual.co...r-manuals.html