4720 overheating running hot need advise

Brown Dog · Jul 5, 2017

I have a 4720 open station E-Hydro 400hrs running way too warm & has warning lights on at times.

No leaks. Full of coolant. Has ran too warm since I bought with 130hrs.

I only use it for Mowing with 110" RFM. Loader stays off.

Radiator, Intercooler & air filter are all clean.

Muffler gets the fuel in tank hot.

Would removing the Tstat help IF it has one ?

I don't see how a cab unit with AC could stay cool with so much hp crammed in the little engine compartment.

Any Help or Advise ?

texasranger556 · Jul 5, 2017

Fan belt and fan in good shape? Do you get any dandelion fuzz stuck on the grill when mowing? I would try a new thermostat next, don't think removing it is a good idea.

Brown Dog · Jul 5, 2017

Yes the grille catches lots of fuzz & grass.
Always has tho. I keep it cleaned off.
Fan & Belt both are in good shape.
Idk if it has fan clutch or not ?
The Hydro & 66hp is a LOT to keep cool with it's TINY radiator IMHO

Spanner · Jul 5, 2017

Running warm since you bought it second-hand?

First: confirm you have Anti-Freeze/Corrosion Inhibitor in the radiator @ 50% concentration and not just plain water?

Second: check and verify that the fan is turning the correct direction to draw air through the radiator from front to back?
(It has been seen that the serpentine belt can be mis-routed by unwitting, but well-meaning installers - Particularly if it has been supplied incorrectly.)

The thermostat is a unique style and sits in the top of the Timing Gear Cover beneath the Top Radiator Hose. Held in place by a Snap-Ring (Circlip) which needs to be removed to release the thermostat itself after removal of the Radiator Hose.

No loss of coolant implies no issue with the Head Gasket etc.

There was an upgrade to the seal between the Timing Gear Cover and the Cylinder Head itself (On early models) so ensure your engine has complied with this. You may need to speak with the previous owner.
:wrench:

kthompson · Jul 5, 2017

If the tractor is about 47 hp seems it would be fine with that size mower unless really heavy cutting or too high speed or a combo there of. Unless the cutter has issue placing extra load on the tractor such as wheels not turning freely or gear box or spindles.

Running a cutter steady to me has proven to be one way to really test the cooling of my tractors also you are pushing the engine rpms to get the pto rpms. All push heat.

Does the tractor have just a standard 540 pto or does it have (not sure what JD calls it but step up on pto speed at lower engine rpms for such as mowers) if so have you tried the other option than the one you are using?

I would back up to the basics also, when tractor is cool wash the fins of the radiator with lots of water at low pressure and change the air filter. If you are 100% sure the air filter it clean then try blowing it out with air pressure from compressor or leaf blower. Some filters hide how dirty they are the way they are design.

If you have an infrared thermometer check the radiator for any cool areas of the radiator indicating clogs.

Be sure your brakes are fully released, on hydrostat transmission sometimes hard to tell. Use thermometer to see if hubs get hot, one more so that other.

DFB · Jul 6, 2017

I needed to replace the water pump on the 4320 at work around 500hrs. Notice any problems there?

Brown Dog · Jul 6, 2017

I bought this tractor used with 130hrs from South Dakota. I'm in the Georgia HEAT.
Not sure if different regions / areas run different Tstats ?
It's never had a wrench on it or been cobbled up in any way.

It has 50/50 coolant.

Fan turns correct way because grass sucks to front of grille & radiator.

It runs hot with throttle set at 2500rpm & 2100rpm both.

I'm going to replace the air filter ASAP

Brown Dog · Jul 6, 2017

Replaced fuel filter, inner & outer Air Filters.

Temporarily removed (destroyed getting out) Tstat to run & see how warm gauge will read.

Blew radiator & intercooler out again then washed with water.

Stay Tuned .....

jenkinsph · Jul 6, 2017

Brown Dog said:
Replaced fuel filter, inner & outer Air Filters.

Temporarily removed (destroyed getting out) Tstat to run & see how warm gauge will read.

Blew radiator & intercooler out again then washed with water.

Stay Tuned .....

I have had my 4520 cab for about 8 years now and last week I was cleaning it up and going through everything. I decided to take the intercooler off the stack to do a better job cleaning the ac condenser. With a good quality condenser cleaner I was able to get a lot of dirt and debris out. Definitely worth the trouble to r/r the intercooler about a 20 minute job off/on. In working the tractor today it was cooler in the cab and the engine temperature was lower too.