JCB 8026 digger overheating

[Guineafowl]

Perkins engine.

Plenty of coolant in it, but after prolonged work it sounds the buzzer and gives the coolant warning symbol.

Fan belt ok.
Slight play in the water pump bearing.
Radiator not too badly clogged but hard to get to.
Viscous fan reasonably easy to turn even when hot - is this right?
Rad seems full of hot water so probably not stuck thermostat (where is it?).

Plan is to blow out the rad carefully.

Any way of checking if the water pump is turning?

 

[8ob]

First thing to check is whether the hi temp warning system is telling the truth.

Bob

 

[jsf55]

Blow out the air filter while your at it check fan is in good condition and the coupling is ok, all from my experience

 

[Guineafowl]

First thing to check is whether the hi temp warning system is telling the truth.

Bob

So get it to do the fault again, then measure the temp with an IR thermometer or similar? It’s not discharging into the expansion tank, so you might be right. What temp would a working alarm typically sound at?

 

[Guineafowl]

Blow out the air filter while your at it check fan is in good condition and the coupling is ok, all from my experience

Will do.

I thought a viscous fan was meant to lock up at operating temp, but this one doesn’t.

 

[Barking Mat]

So get it to do the fault again, then measure the temp with an IR thermometer or similar? It’s not discharging into the expansion tank, so you might be right. What temp would a working alarm typically sound at?

I think every sensor has a temp stamped into it, so manufacturers can choose.

Should say in workshop manual.

 

[Bornfree]

Will do.

I thought a viscous fan was meant to lock up at operating temp, but this one doesn’t.

Do the rolled up newspaper test.

 

[8ob]

So get it to do the fault again, then measure the temp with an IR thermometer or similar? It’s not discharging into the expansion tank, so you might be right. What temp would a working alarm typically sound at?

High nineties would be about the point the alarms start kicking in.

Bob

 

[jsf55]

That should be fine, i don't think any lock up ?