Coolant Leak

[SidewinderConvert]

Was going to check the chain tension on the sled this morning when I noticed anti-freeze on the ground below the machine. A little bit more investigation revealed the source to be the coolant line on the exhaust side of the sled above the drive sprocket.

After taking many things apart, the problem appeared to be the short rubber hose between the front and back radiators on the tunnel.

The back hose clamp (6mm drive) was already tightened down, after picking the glue off the front hose clamp (7mm drive) that one was only finger tight.

Does anybody know if the difference in hose clamp sizes is typical? Seems odd to me that the factory would put two different size hose clamps right next to each other.

EDIT:

It wasn't just the hose clamp, the hose itself was comprimised.

 

[ClutchMaster]

It’s pretty common to find loose hose clamps on these straight out the factory. They must have Girl Scouts workin at the AC factory.

 

[SidewinderConvert]

It’s pretty common to find loose hose clamps on these straight out the factory. They must have Girl Scouts workin at the AC factory.

Thing that concerns me is this is a 2018 with 1200 miles on it that I bought this spring. The guy who owned it before must have been just dumping anti-freeze into the sled every weekend he ran it.

 

[RAMSOMAIR]

Not likely. They tend to leak sporadically

 

[SidewinderConvert]

After letting the machine sit overnight, tightening that fitting really helped but there was still coolant on the bottom of the tube. Looking closer this is what I saw.

Another story of need BOP hose savers

 

[SidewinderConvert]

I elected to replace the hose at the front of the tunnel because that little nick was concerning me even though it wasn't leaking right now. Here is what the inside of the hose looked like. That would have definitely failed at some point this year!

Full Res Image Here:
https://i.imgur.com/b2JXElr.jpg

As a side note has anybody replaced this hose with a thicker walled hose before? If so does it fit below the BOP hose savers?

 

[hibshman25]

I elected to replace the hose at the front of the tunnel because that little nick was concerning me even though it wasn't leaking right now. Here is what the inside of the hose looked like. That would have definitely failed at some point this year!

Full Res Image Here:
https://i.imgur.com/b2JXElr.jpg

As a side note has anybody replaced this hose with a thicker walled hose before? If so does it fit below the BOP hose savers?

The hose protectors fit pretty snug on the hose. If you opt to go with a thicker hose the protectors can easily modified to work. Just lay a larger diameter socket or pipe inside the channel and hammer it down to spread the channel open a little more where it slides over the hose. The aluminum is a 5000 series so it will not take a lot of force to open it up a bit.

 

[SidewinderConvert]

I decided that if I was going to replace the hose on this guy I may as well put a better part in. I was able to get this guy with almost the same dimensions but has a lot more reinforcement/strength than the stock hosing. The most difficult part will be getting a hose clamp strong enough to seal on the back radiator which doesn't have a barb to grab on (pressure testing the cooling system now).

 

[SidewinderConvert]

With the snow we got today in Central Wisconsin I decided to doodle around a little bit to test the cooling fix. No coolant appears to be leaking... However it immediately overheats. I can idle on the stand for ~10-12 minutes (guesstimate, never actually measured yet) from cold before the coolant hits 180F. When idling you can see the temperature climbing to 165 then drop to 163 for a bit when the thermostat opens then slowly climb from there. However, as soon as I started to put the engine under any load (running around my yard at 10-40mph) it would overheat inside a minute. I was throwing up what would seem to be plenty of snow to cool the radiators. Feeling the tunnel on the rear radiator the tunnel is warm to the touch but not hot like it got on the stand. I am not sure if this is due to coolant not cycling or the snow that was kicked up running around the yard.

The cooling system was drained almost entirely when replacing the broken hose and refilled with 50/50 premix antifreeze. When filling the system I had to fill from the pressure cap as the system did not seem to want to draw from the tank. Filling I had the track off the machine still and dropped the tail down so the tail-flap was touching the ground while the skis were on dolly carts. I added coolant until it quit bubbling at the fill cap (~0.75 gallons used).

After finding the sled was overheating I jacked the front up as high as my floor jack would lift it (skis 9-10 inches off the ground) and ran the sled until 180F to try removing air bubbles from the track radiator for no change.

I do not have any water wetter on hand, I will be picking some up tomorrow and adding some to the system. Is there anything obvious I am missing here? Once again the system does not appear to be leaking coolant but is just not cooling.

 

[Sevey]

Only have done it once but I had the front end up higher than what you described. I hung the sled from the ceiling with a come along. It took awhile of filling and then rocking the sled back and forth but eventually got the coolant in and worked the air out
Ms

 

[Turboflash]

These 998s can be tough to bleed. I've done it a few times. Did you remove the little plug in the small tank over by the turbo? That lets air out of system. My best luck to get the air out of mine was to have that corner of sled the highest and as Sevey says, try to have the front at least 2 ft. higher than back. I'd try running sled with front end as high as you can get it, with that little plug out of tank. I bet there will be lots of air coming out. Watch closely though because as soon as the air is gone, coolant will come gushing out of the little tank. Then let it cool down on the level, then fill coolant overflow tank to the line.
IMO, if that doesn't work, any chance your water pump impeller failed?

 

[SidewinderConvert]

These 998s can be tough to bleed. I've done it a few times. Did you remove the little plug in the small tank over by the turbo? That lets air out of system. My best luck to get the air out of mine was to have that corner of sled the highest and as Sevey says, try to have the front at least 2 ft. higher than back. I'd try running sled with front end as high as you can get it, with that little plug out of tank. I bet there will be lots of air coming out. Watch closely though because as soon as the air is gone, coolant will come gushing out of the little tank. Then let it cool down on the level, then fill coolant overflow tank to the line.
IMO, if that doesn't work, any chance your water pump impeller failed?

Will do, I didn't even realize until just now that there was a second tank beyond the overflow tank.

 

[Turboflash]

BTW- not sure how empty your whole system was but .75 gal. seems a little short. I think an empty system takes almost a full gallon.

 

[SidewinderConvert]

Yup, after lifting the whole front of the sled ~3-4 feet in the air and opening the cap up it took another 1/2 quart of coolant. Going to let the system cool down then open up the cap on the tank and see if it is still low.

 

[SidewinderConvert]

Checked the tank and it had a bit of air in the top but plenty of coolant present. I put the machine together and ran around the yard until I was starting to see snirt and didn't ever see a running temp over 183F. It seemed to want to run around 175-180F which seems warm but I was being very careful to not spin the track and wreck my lawn.