B2910 Weird Overheating Symptoms

[Blkvoodoo]

I've got to wonder too, is the core of the radiator open to air flow thru it ?

I've seen this many times in forklifts ( I'm a lift tech ) where customer will wash the lift or hose out the radiator to clear the dust out, but in reality they are causing the dust to turn to mud and it will dry and clog up the fins between the core tubes, you won't easily see it unless you know to look for it.

with a BRIGHT flashlight, shine thru the front of radiator and look for light thru on the back side, there should be decent light transmission thru the core, if it's dim or no light, I'd suspect the rad core is dust bound and needs to be pressure washed ( removal of rad recommended, and lots of soap, laundry or dish soap is adequate, and careful use of pressure washer thru the core )

 

[HThomure]

I've got to wonder too, is the core of the radiator open to air flow thru it ?

I've seen this many times in forklifts ( I'm a lift tech ) where customer will wash the lift or hose out the radiator to clear the dust out, but in reality they are causing the dust to turn to mud and it will dry and clog up the fins between the core tubes, you won't easily see it unless you know to look for it.

with a BRIGHT flashlight, shine thru the front of radiator and look for light thru on the back side, there should be decent light transmission thru the core, if it's dim or no light, I'd suspect the rad core is dust bound and needs to be pressure washed ( removal of rad recommended, and lots of soap, laundry or dish soap is adequate, and careful use of pressure washer thru the core )

You're talking about immediately behind the fan. I'm not all that familiar with the term "core" as it relates to a radiator. I assume you're talking about the "finny" part.

OK. I'll do that, too. Thanks.

 

[Blkvoodoo]

yes, the radiator "Core " has the fins and tubes between upper and lower tanks, coolant flows thru the tubes, fins draw the heat out as air passes over them. dust dirt and debris gets caught up between the tubes and fins and blocks air flow

If you're machine doesn't have a screen in front of radiator you might want to make one to help keep it cleaner. keeps larger grass and "stuff" out of the core.

 

[North Idaho Wolfman]

Cold be a bad water pump, just because the air burped out of the engine doesn't mean the water pump is moving water.

But lets back up:

#1: You need to make sure it's not a head gasket or other sealing problem.
With a cool tractor, open the radiator cap, make sure the fluid is full, start the tractor and look for bubbles in the radiator.
While your doing that, also look to see if the water is moving in the radiator, a little food dye can help with this.

#2 You need to get another input for temperature, it could be as simple as a bad temp gauge sending unit. When the gauge is saying hot is actually normal temp.

#3 When is that last time you did a motor and hydraulic oil and filter change? Heat can also be generated from dirty fluid and filters.

#4 When you engage the mower deck does the tractor bog down? If it does, it could be a problem with the decks drive box or bad bearing?

 

[HThomure]

Cold be a bad water pump, just because the air burped out of the engine doesn't mean the water pump is moving water.

But lets back up:

#1: You need to make sure it's not a head gasket or other sealing problem.
With a cool tractor, open the radiator cap, make sure the fluid is full, start the tractor and look for bubbles in the radiator.
While your doing that, also look to see if the water is moving in the radiator, a little food dye can help with this.

#2 You need to get another input for temperature, it could be as simple as a bad temp gauge sending unit. When the gauge is saying hot is actually normal temp.

#3 When is that last time you did a motor and hydraulic oil and filter change? Heat can also be generated from dirty fluid and filters.

#4 When you engage the mower deck does the tractor bog down? If it does, it could be a problem with the decks drive box or bad bearing?

Actually, there is a slight drop in RPMs when I engage the deck. I usually put the needle a smidge past the PTO hash mark on the tach, and when I engage the deck, it drops to a smidge below the hash mark. I don't know how much of a drop that is, I've never done the math. I always just attributed it to the fact that I was running at 72" finish mower on a 30 hp tractor. I do know that the oil and grease are only a few running hours old.

 

[North Idaho Wolfman]

A little drop in RPM is normal, move back to the top of the trouble shooting list.

 

[HThomure]

So I came to the tractor this morning and checked the radiator core, and there was indeed some blockage. So I sprayed it all out real good got it all nice and clean, then fired it up. I ran it for an hour, maybe an hour and a half, and it still got warm, but never even approached overheating. So I would say that helped quite a bit.

Then something even more interesting happened. I had some thicker grass I needed to cut down, so I took the finish mower off and hooked up the brush hog. The brush hog is only a 60 inch, as opposed to 72 inches on the finish mower. I mowed for several more hours after changing to the brush hog, without giving the tractor any time to cool down in between, except for the time it took to change out. The tractor ran substantially cooler with the brush hog than it did with the finish mower, even though I was grinding through much thicker grass. I find this kind of interesting.

My next project will be to change the gear oil and grease up the finish mower real good. We'll see what that does.

Speaking of maintenance on the finish mower, I recently changed out the belts, but was very unsure of how much tension to put on the new belts. Is it possible for them to be over tightened and be creating more strain on the engine? And how do I determine how much tension I need?

 

[Blkvoodoo]

then fired it up. I ran it for an hour, maybe an hour and a half, and it still got warm, but never even approached overheating. So I would say that helped quite a bit.

"warm" is half way up the gauge, and thats where it should be "normally" if you're working it hard it'll creep up to the red but should never touch the line unless there is some air flow blockage too the radiator.

The tractor ran substantially cooler with the brush hog than it did with the finish mower, even though I was grinding through much thicker grass. I find this kind of interesting.

where are you running the RPM's with the finish mower as opposed to the bush hog ? I don't have a bush hog, but if I did I'd expect to run it at max PTO RPM, anything slower could cause damage as it doesn't have power to knock/beat thru what ever it's cutting. Finish mower ( mine is belly mower ) I run about 2300-2500rpm on tach unless it's real heavy grass, then it's full steam ahead. ( 2800 RPM )

My next project will be to change the gear oil and grease up the finish mower real good. We'll see what that does.

Speaking of maintenance on the finish mower, I recently changed out the belts, but was very unsure of how much tension to put on the new belts. Is it possible for them to be over tightened and be creating more strain on the engine? And how do I determine how much tension I need?

anything is possible, if you can easily turn the whole mess by hand ( engine off and PTO disconnected from tractor ) it should be fine. if not, pull belt(s) and figure out where the drag is coming from. I was greasing my mower yesterday and found that the tensioner pulley had dropped on the shaft it rides on, there is ( WAS !! ) a clip that keeps pulley at certain height and it appears to have removed itself.

 

[kuboman]

Having the belts too tight will not strain the tractor. Having the belts loose would make everything work harder because the mower would not be running up to speed under load.

 

[ShaunRH]

Most belts are considered 'tight' if they deflect about ½" when pushed at the centerline between pulleys. Less deflection is 'too tight' and anything more than about ¾" is too loose. The problem with this rule of thumb is that it entirely depends on the length of the run of the belt between pulleys, so each device should have some way to gauge the tightness properly. That should be in the user or shop manual for the device.

Too tight doesn't strain the tractor per se, but it does strain the bearings, prematurely wearing them out. Too loose wears out the belts and the pulleys faster, as well as not letting the driven tool be as powerful as it should be.

 

[North Idaho Wolfman]

Most belts are considered 'tight' if they deflect about ½" when pushed at the centerline between pulleys. Less deflection is 'too tight' and anything more than about ¾" is too loose. The problem with this rule of thumb is that it entirely depends on the length of the run of the belt between pulleys, so each device should have some way to gauge the tightness properly. That should be in the user or shop manual for the device.

Too tight doesn't strain the tractor per se, but it does strain the bearings, prematurely wearing them out. Too loose wears out the belts and the pulleys faster, as well as not letting the driven tool be as powerful as it should be.

Very well stated!
100% agree