Komatsu guys - PC300LC-3, coolant in oil.

[02Dmax]

Wondering where to start on this old girl. It has antifreeze the oil now, about 2 gallons near as I can tell. Water pump? Liner? Head gasket? There's not alot of Kom stuff around here and most everything has Cummins power. This one is all Kom counterweight to bucket. Any pointers appreciated.

 

[jey_c]

start with water pump, this is the easiest

 

[02Dmax]

Is it common for the water to let coolant into the crankcase when they fail? I hate to pull the oil pan but with a water pump costing $1000, I'd hate to put one on just to find out its something else.

 

[Nige]

Let's start off with what we know. OK, there is coolant in the oil - is there also oil in the radiator..?

if the answer is no it doesn't sound like the engine oil cooler so at what locations can coolant get into the lube system without the reverse happening..?

To me the obvious choices would be the water pump (as already mentioned), cylinder liner seals, or cylinder head/gasket. Not knowing the engine that well I'm at a disadvantage but if it was mine I'd be dropping the oil pan and putting some pressure into the cooling system to see whether or not I ended up with raindrops falling on my head from above. All it costs is a bit of time and an oil pan gasket.

 

[02Dmax]

No oil in radiator. I'm going to try and talk him into letting me pull the pan. All the bottom shields are missing already and its going to need an oil change anyhow.

 

[tctractors]

The waterpump would be absolute odds on for your trouble, it does have a weep hole set into the casing of the pump that usualy gets blocked off with crud, so firstly locate this hole and clear it, then see if coolant leaks from the now cleared hole after the rad has been topped up, the pump is easy to re-seal and there is a service kit to do this task at very low cost.
tctractors

 

[02Dmax]

Thanks tc. I already pulled the oil pan and confirmed that it is in fact the water pump. Where can I get one of these kits you speak of? Lol. My dealer says only a new one is available. $975

 

[tctractors]

I am sure there is Komatsu none O.E. dealers in the U.S.??? we have a very good 1 in the U.K. the water pump kit comes with bearings and the gland seal plus a few other oddments, its about 2 hours work to press them to bits, then clean up things and refurbish the pump, I seem to think the kit is around £65, was the little weep hole blocked?

tctractors

 

[02Dmax]

Yes, the little weep hole was totally clogged shut. They did finally come up with a reman pump. Supposed to be in KC Monday morning so we'll find out if its correct. Kit was not an option though. Customer bought 2 more machines like this so looks like I'll become familiar with them.

 

[jofc]

Pretty common on those engines. A later design has the weep hole replaced with a nipple that you attach a hose to, you then remotely mount the hose where dirt won't build so well.