Australian Earthmoving – June 2018

MAINTENANCE

If you’re using a modern long life coolant,

routine water filter replacement isn’t necessary.

Down at the bottom of the list of possible

causes of overheating is poor circulation caused

by problems with the thermostat or the pump.

Whilst the temptation to give the ‘stat the old

heave-ho as a first step to fixing an overheating

problem is strong, they really don’t play up all

that often. If it’s suspect, the old put-it-in-a-

pan-of-boiling-water test is still valid. Water

pump impellers have been known to break up

or fall off, but if this happens, within minutes

the engine will be pinging and perking like a

$10 coffee percolator from Aldi.

Troubleshooting.

Giving troubleshooting guidance for

earthmoving machinery is difficult given it can

be anything from a plate compactor to a mining

truck, but here are some guidelines.

First off, check if an overheating problem

actually exists. If the temperature gauge

reads 120C and it’s spitting coolant out of

the overflow bottle then yes, it’s probably

overheating. If the temperature gauge is

reading 355C and the machine’s working OK,

it’s either lying or you’ve broken it.

Once we’ve established that we have an

overheating problem, the first fundamental

question we need to ask is “is the cooling

system not working properly, or is the machine

producing more heat than the cooling system

can handle?” This can be a tricky one to

answer. We can get guidance by using an IR

temperature gun to check the temperature of

the radiator inlet and outlet and comparing

the difference (delta temperature). If we get a

temperature drop of around 8 to 12 deg c, we

can say that the radiator is probably rejecting

enough heat and the problem may be due to an

overload situation. Much less delta temperature

and the radiator may have a problem due to

external blockage or low air flow. Much more

and we may have a coolant flow problem due

to internal blockage, thermostat or pump

problems, but bear in mind that if run for

long enough, a cooling system with low flow

will eventually bring up the radiator outlet

temperature as the heat soaks through the

system.

Conclusion.

Modern earthmoving equipment cooling

systems work well and are more reliable than

they have ever been, but they’re still not fit and

forget unfortunately. Give them a little bit of

love by keeping them full of the correct coolant,

checking the belts occasionally and cleaning

the radiator and they should give you good

service.

AUSTRALIANEARTHMOVING.COM.AU 62

Good pulley