Radiator fan cycling heavy in reverse

[jaketheram]

Hey all, been lurking here since I purchased my Kioti CS2510 back in the spring. It was used, year old w. 50 hours at the time. Sitting at about 102 now.

Picked up an older Meteor 51" 3pt snowblower to use on my drive this winter and I do my neighbors also for her.

First time or two, worked great, no issues.

2nd to last time, worked fine for my drive (which is a lot of back and forth/forward and reverse using both loader and blower). Start doing hers (which is long and straight) and as I'm going down hers it sounds like the radiator fan is kicking into overdrive. I also can't be 100% on this, but possible felt like I was slowing down, however, her drive does dip down at first before going slightly uphill. It cycled like this a few more times as I did her drive, each time I got the feeling that I was progressively losing velocity. Only seemed to happen in reverse, and only after 30 seconds or more of continuous reversing.

Checked the temp and the needle is where it always, slightly cooler than the midpoint on the gauge.

Checked HST fluid level a few days later, it was a little low, bottom of dipstick so filled up, took less than a quart I would estimate.

Snowblowed again yesterday evening, same thing, fine for all my drive. Fan cycled loudly once backing down her drive the first pass, but the subsequent passes, while the reverse speed still seemed to progressively decrease, the radiator fan did not howl.

RPM of engine never seems to change throughout all this, I run it at 3000rpm, which is the rated speed for 540 PTO RPM.

Any thoughts?

I used it extensively this past summer and fall: trenching with the hoe, grading, mowing with the MMM several acres, never ran into this issue, but also was never going in reverse for longer than a 10 seconds.

I checked HST fan in case I was confused where the noise was coming from, all fan blades are in tact on that.

 

[CobyRupert]

Can't imagine how the radiator fan has anything to do with going in reverse.

 

[WranglerX]

Check radiator for leaves. weed and crap accumulated over summer use...

Dale

 

[jaketheram]

Coby- I agree with you. Only thing I could think of is the radiator isn't getting as much airflow in reverse (edit: not to mention ambient temps in the 20's)...but temp needle gauge show's no sign of overheating. Also doesn't make sense why I'd be losing velocity because the fan is spinning fast, unless there is some underlying cause of both. I really don't think it's the HST fan as that's directly underneath the seat and I am fairly certain this is coming from the front of the engine.

DL- Sorry, I should have mentioned that I had checked that and the radiator was clean. The tractor is stored outdoors (on concrete pad under a portable garage) so I check the engine bay often for signs of mice nests, so far they've left me alone.

 

[crashz]

Do these have clutches on the radiator fans? Never seen one on a compact tractor. Both of my tractors have a plastic fan attached to the water pump. No clutch.

Something sounds fishy with the HST. Have you changed the HST and/or hydraulic filter? Internal filter /magnetic may need to be cleaned? Maybe the reverse pedal is not adjusted properly?

 

[Ford850]

This almost sounds like you are fully depressing the reverse hst pedal and it is losing power and gaining heat. Similar to having it in too high of a range and fully depressing the forward and then climbing a hill and it slows down as the hst struggles. But I don't see how that could happen while snow blowing since you are no doubt in low range already, unless you are in deep snow. I'd experiment by easing up on the reverse pedal a bit.

 

[ericm979]

Often the fan is engine driven and usually without a clutch. However many machines have an electric fan for the HST cooler when it's not located in front of the radiator. That may be clogged with debris or malfunctioning in some way.

 

[jaketheram]

Crash and Eric, you are both correct, the radiator fan is belt driven by the engine. In my line of work I deal with electric motor driven variable speed cooling fans so I naively assumed this radiator fan had its own electric motor.

This led me to investigate the HST fan power source, which appeared to me to simply be the drive shaft, so checked my service manual and that appears to be case, so it doesn't seem to me it's possible for the HST fan to spool up either, at least not without the drive shaft increasing drastically?



...in which case...now I don't even know what this noise I'm hearing is coming from!

All filters and fluids were done at 55 hours by dealer as part of the 50 hour service. Oil change and oil filter were again done at 100 hours when took the deck off and put the blower on.

Ford, you are right, it almost seems to lose power like being in high range and going up too steep a grade. However, I am always in low when blowing snow, and I'd say her drive at it's steepest gains 1 foot elevation per 10. This past snowfall was only about 4". Blower and engine never bogged. I do have the pedal pressed down pretty far when doing her part of the drive, as its long, straight, and relatively level.

I will experiment with giving it less pedal and see if it stops making the noise...but now curious as to what's making it?

 

[ruffdog]

Check radiator for leaves. weed and crap accumulated over summer use...

Dale

Make sure you can see light through it....use a light and mirror if needed.

 

[crashz]

Any luck tracing this issue?

Quick question: does the transmission get hot? When running, can you put your hand on the case comfortably?

Since the HST controls direction and flow, this would be my first place to look. You checked fluid, filters were replaced recently. What about the pedals? Maybe the adjustment is out. Is there ever a hint of this behavior when traveling forward?

 

[jaketheram]

Any luck tracing this issue?

Quick question: does the transmission get hot? When running, can you put your hand on the case comfortably?

Since the HST controls direction and flow, this would be my first place to look. You checked fluid, filters were replaced recently. What about the pedals? Maybe the adjustment is out. Is there ever a hint of this behavior when traveling forward?

Thanks for checking in.

Actually tonight was the first time I was back on it, we had a few inches of light snow. I did mean to put a hand on the HST but by the end of blowing my hands were frozen pretty bad, couldn't find my gloves and wanted to get done before dark.

I think you may be onto something with the pedals- reverse has always felt a tad slow, and today it seemed to lose "power" or speed in reverse without encountering any type of grade and blowing very little amount of fluffy snow, not sure this is pedal adjustment but something just doesn't seem right with reverse.

It never seems slow or to lose power in forward.

However, I think I may have been mistaken initially, the radiator fan isn't spooling up, it actually seems to be shutting down, and what I thought was it spooling up was it just kicking back on. Today it happened once in forward early on and I think once in reverse, where the fan shut off seemingly entirely for a brief period before spooling back up.

Definitely seems to be the radiator fan- not the HST fan.

But I am still confused about how either fan could change speed. As pointed out by someone's earlier post, the radiator fan is belt driven by the engine, and the HST fan seems to be attached to the driveshaft, so not sure how either of those things can shut down without the engine or driveshaft stopping spinning.

 

[ericm979]

Some cars and trucks have electric fan clutches since at speed there's plenty of air flow without the fan. Seems unlikely that a slow speed vehicle like a tractor would have a fan clutch but it's possible.

A weird thought- could the fan be rubbing on the shroud when the engine shifts on it's mounts? Maybe there's a loose or broken motor mount.

 

[mcfarmall]

Never seen a SCUT, CUT or any other farm tractor with an electric fan. Concrete trucks, wheel loaders, and skid loaders yes, but never a tractor.

Can you post a picture of the electric radiator fan on your tractor?

 

[jaketheram]

Never seen a SCUT, CUT or any other farm tractor with an electric fan. Concrete trucks, wheel loaders, and skid loaders yes, but never a tractor.

Can you post a picture of the electric radiator fan on your tractor?

I'm not sure if your question is directed at me, but I think I've mentioned several times since my initial incorrect assumption that the radiator fan is belt driven off the engine. That's why in my last couple posts I have been looking for peoples' input in to how/why the radiator fan shuts down briefly (3-15 seconds) before spooling back up.

As far as the HST slowdown, thanks to @crashz , I did some googling for pedal adjustment Kioti and what came up instead was a fairly common issue for these Kiotis to get bent reverse pedals that reduce the allowable travel. I checked last night and this certainly seems to be the case with mine, it's only an inch off the deck, so I will try bending that back or having dealer order me a new one since it is still under warranty. So thanks for getting me on the right path with that as far as reverse speed, but it appears to be a different issue from the fan.

The mystery still remains about how its even possible for the radiator fan to shut down. I will check engine mounts, but I think if it was hitting its shroud, I would here the THWAP THWAP THWAP of the blades making contact before their motion was stopped, which I don't, but I will check the mounts as well as the inside of the shroud for signs of contact from the fan blades.

Attached is the only diagram from the service manual that shows the fan assembly.

 

[07wingnut]

If the fan is slowing down and the engine speed doesn't drop at the same rate as the fan slows down, then you have a belt slippage problem. That is usually caused by something binding, and if there is no noise from the fan hitting something, this points to an idler pulley starting to seize up, or your water pump doing the same. Loosen the belt and see if idler and water pump rotate smoothly.

 

[jaketheram]

If the fan is slowing down and the engine speed doesn't drop at the same rate as the fan slows down, then you have a belt slippage problem. That is usually caused by something binding, and if there is no noise from the fan hitting something, this points to an idler pulley starting to seize up, or your water pump doing the same. Loosen the belt and see if idler and water pump rotate smoothly.

Thanks, I will check that out. From my memory, there is only 3 pulleys on the belt. The Fan, the alternator, and what must be the water pump. I'll loosen the belt and make sure they all spin freely.

 

[07wingnut]

You probably already know this, but just in case, note that the fan is mounted on the waterpump shaft.

 

[crashz]

Glad you have the HST / reverse issue solved.

The radiator fan is solidly mounted to the water pump flange and driven by the belt. Any change in speed without change in engine speed would be belt slippage as 07 mentioned. i saw no clutch mechanism in the parts diagram you posted. Or its remotely possible that the fan center is broken.

The first thing I'd check is the belt tension, and see of the fan can move freely when the engine is off. If the fan moves under finger pressure, the belt is either not tight or glazed to the point of failure. Most importantly is that the water pump may not be spinning when the fan cuts out, so you could have a real overheating issue there.

Your machine is new, so a little belt stretch isn't unreasonable.