DK551 getting hot

[kjg26]

When cutting the back pasture my 551 keeps getting hot. I turn off the PTO and let it idle for 5 min and the temp goes back to normal. Lasts about 10 min then get to repeat the process.

6ft bush hog. Medium range and in 4th gear. Happens slower if I'm in 3rd gear. Grass is about waste high. Decent thickness.

New fluids and filter less than 5 hours ago. Hydraulic, fuel, and oil.

Radiator screen is clean.

Am I just asking too much over her? Slow it down more?

I need to get a deep clean on the radiator but shes not dirty from what I can tell.

93 degrees out

Any input?

 

[5030]

When cutting the back pasture my 551 keeps getting hot. I turn off the PTO and let it idle for 5 min and the temp goes back to normal. Lasts about 10 min then get to repeat the process.

6ft bush hog. Medium range and in 4th gear. Happens slower if I'm in 3rd gear. Grass is about waste high. Decent thickness.

New fluids and filter less than 5 hours ago. Hydraulic, fuel, and oil.

Radiator screen is clean.

Am I just asking too much over her? Slow it down more?

I need to get a deep clean on the radiator but shes not dirty from what I can tell.

93 degrees out

Any input?

Most times you cannot see the crud in the rad. I suggest blowing it out from the fan side and then a good wash out with a strong stream of water. I clean both of mine almost every day on my Kubby's. The rad screens stop the big stuff but the little stuff goes right through and gets in the rad.

 

[kjg26]

Copy that. Will start there

 

[justman777]

Most times you cannot see the crud in the rad. I suggest blowing it out from the fan side and then a good wash out with a strong stream of water. I clean both of mine almost every day on my Kubby's. The rad screens stop the big stuff but the little stuff goes right through and gets in the rad.

X2. Radiator may look clean, but smaller stuff will bypass the screens and get lodged in there. Only comes out with an air compressor. I bought a special nozzle for my air compressor from Northern Tool that gets between the radiators and coolers to blow them out towards the front of the tractor. If the engine starts running hot, I'll throttle it down and drive over to the garage and use the air compressor to blow everything out. You don't want to turn it off, and no water unless it's cooled down for several hours.

 

[ritcheyvs]

Go easy on that thing. Another DK55 owner here melted the seals for the PTO clutch actuator. Once those clutch plates start to slip the additional heat really cooks things. I never did this job (replace PTO clutch seals) but it looks like a really awful job ... many man-hours. So don't overheat that thing. The engine cooling system is very simple so be sure it is healthy; check the belt, thermostat, fluid level, and clean the radiator (flush or blow it out from the backside). My DK451 temp always stays between the dots on the temp gauge. There were some posts here suggesting that overheat may be a DL55/551 problem.

 

[boomer1025]

When cutting the back pasture my 551 keeps getting hot. I turn off the PTO and let it idle for 5 min and the temp goes back to normal. Lasts about 10 min then get to repeat the process.

6ft bush hog. Medium range and in 4th gear. Happens slower if I'm in 3rd gear. Grass is about waste high. Decent thickness.

New fluids and filter less than 5 hours ago. Hydraulic, fuel, and oil.

Radiator screen is clean.

Am I just asking too much over her? Slow it down more?

I need to get a deep clean on the radiator but shes not dirty from what I can tell.

93 degrees out

Any input?

Well being 93 degrees and most likely high humidity didn't help.
You might want to go slower and try that, should lessen the load on the engine.
Next don't wait till the grass is waist high to mow. Knee high is the best height to mow at and the grass is still green. This helps keep if not stop the radiator & screens from plugging and overheating.

 

[YLee Kioti]

Most times you cannot see the crud in the rad. I suggest blowing it out from the fan side and then a good wash out with a strong stream of water. I clean both of mine almost every day on my Kubby's. The rad screens stop the big stuff but the little stuff goes right through and gets in the rad.

Exactly what happens. I just finished clearing a neglected pasture for an elderly gent.
First time ever the gauge went near the red zone.
Shame on me, I failed to bring my leaf blower.
Took a water hose and washed out all the stuff the eye could not see. Amazing what came out.

When I got it home and gave the machine a thorough washing, used this tool for the radiator.
https://www.amazon.com/Radiator-Gen...=gateway&sprefix=radiator+wand,aps,228&sr=8-1

FWIW also used it on all the vehicles. Wash out the radiator and condenser. Once the debris is washed out the AC seems to work so much better.

 

[kjg26]

Actually ordered one of those earlier today. I'm working on taking back a neglected pasture for a prop we recently bought. So....I'll struggle on. As soon as she goes above the top dot I idle down and let her cool. Cools quick and good to go. Only has 450 hours in her. Is topped off belt is in good shape. Fan in good shape. Dunno about the tstat

 

[YLee Kioti]

Actually ordered one of those earlier today. I'm working on taking back a neglected pasture for a prop we recently bought. So....I'll struggle on. As soon as she goes above the top dot I idle down and let her cool. Cools quick and good to go. Only has 450 hours in her. Is topped off belt is in good shape. Fan in good shape. Dunno about the tstat

T-stat should be fine. These engines are not like the old truck diesels where cavitation and coolant issues created so many problems with cooling components.

You'll really enjoy the many uses of the wand. BTW, if you have room to haul the leaf blower behind the seat it may help to blow out the rad. when it the gauge first indicates an increase. Lesson learned for me when cutting someone else's place and my support equipment is at home....heh...heh...even old farts have to learn the hard way it seems......

 

[kjg26]

Storage is def lacking on this thing. Working on finishing the canopy and I'll see what I can hang off it. Thx all for your input. We will see what the wand gets out.