Author Topic: Mechanical seal failure (Read 2533 times)

Piney0 · « **on:** October 13, 2014, 11:13:10 PM »

Well, I had my first big carnage happen on Sunday.

I should of known better, it gave me a warning, but i got sidetracked and didn't check it out.

The mechanical water pump seal went on me. It caused the head gasket to blow I guess when it was over heating. I tried hitting the kill switch to turn it off cause of a weird sound and it didn't want to turn off because of detonation, had to stall it using the clutch. At this point i got the quad towed home by the utility quad which was riding in our group.

On Monday, I assessed the damage. I started by pulling the front fenders to check coolant in the radiator, and didn't see any. Put some water in there and watched it drip out the weep hole. From there, I removed the head to check that out. The head nuts were loose, tighter than hand tight, but less than 5 ft. lbs. torque on them. Definate failure on the head gasket in multiple spots between the cylinder and coolant passages. The cylinder lining blued by the exhaust port about an inch down from the top to about the half way point around the circumference around the cylinder. In the pics you can see scoring, but that was from a previous seizure where I only did a light hone.

From there, I started pulling apart the waterpump. Pulled off the cover, the plate and the impeller. The rubber on the seal appears broke to me exposing the spring. I never had one apart before, so I could be wrong about this, but I know it's bad since the coolant came out the weep hole.

I don't plan on pulling the cylinder, I think it's able to run, it still had a nice castor film on it. I'm planning on getting the head decked, getting a new head gasket, and the waterpump seals / gaskets. Since the head nuts were loose, I think the studs stretched when the head got so hot. Should I replace these too?

I feel like I was less than 30 seconds away from melting the piston, I am curious as to what that sound was that I was hearing, I don't know if it was detonation, or the air pressure building up and releasing out the weep hole. It sounded similar to a paint spray can being shook with that rattling sound.

The warning it gave me was a wet spot on the frame by the weep hole, I got sidetracked and didn't confirm if it was a leak or just wet from a puddle. I don't think I'll make that mistake again and will be checking it all the time now.

What are your guys thoughts, am i crazy for not pulling the cylinder? What do you think that sound was? anything else I'm missing or should be checking?

[video=youtube_share;6363qKQd96g]http://youtu.be/6363qKQd96g?list=UU2dj-D-fIGWz-mEIGgDz3iA[/video]

Pumashine · « **Reply #1 on:** October 13, 2014, 11:40:09 PM »

You definitely warped the head. When you say deck the head I assume you are going to have it machined flat or sand back to flat with a flat surface. The head studs are only a couple $ each so you should probaly put new ones in. I would run it. You will need to remove the clutch cover to press the mechanical seal out. Looks like you made out pretty good with no major issues. The noise is probably water in the pipe or pressure in the water passages.

Piney0 · « **Reply #2 on:** October 13, 2014, 11:56:05 PM »

Yes, I mean have it machined flat by a local machinest. Just take off what's needed to get it true. Good point on head studs being cheap, and thanks for the assurance on running the rest. I didn't realize i had to take the clutch cover off, That's a good thing though, cause for the last 2 or 3 rides I have been noticing the clutch slipping a little and procrastinating. I feel like I was very lucky I shut it off when I did.

Thanks for your input.

broken1 · « **Reply #3 on:** October 14, 2014, 12:42:19 AM »

The seal looks normal except for where it's dented on the left side, the spring is exposed like that when the impeller is off. These engines are pretty resilient & can take a beating. Might be a good idea to measure the bore at least where it turned blue though........ Mine sat for two years & the rings got seized to the cylinder, I put in a little marvel mystery oil, used a breaker bar on the flywheel nut to break it loose, put in more oil, cranked it over for awhile with an air impact gun & fired it up. It's been 3 years since than with the same wiseco piston & rings.