What's this for on a Komatsu PC75-2UU?

[td0g]

Hi everyone, been waiting like 4 months for a confirmation email to get through so I could get on here and it finally came just in time for me to have a problem with my excavator! I noticed that I was loosing a lot of coolant and went under the machine and found this thing under the cab in the half open position, I *think* the coolant stopped going down when I closed it. Is this a shut off for the cab heater core or something unrelated?

 

[John C.]

Is your machine painted purple? That model was usually a gray market machine to North America. As I recall the fuel tanks were under the cab as well and there was a valve to drain the bottom bowl on the tank. If that valve solved your coolant problem, then I'm guessing you are correct in it being a drain for the heater core although I've never seen that.

 

[td0g]

Yes it appears it was originally purple and you're probably right it is for the fuel bowl and it was just water/diesel from that mixing with the coolant in the pan that I was seeing on the ground. I've still got a coolant leak somewhere I can't easily see it I guess. I took the bolts off the left side body piece and some coolant came out of those but I couldn't figure out how to get the panel off.

 

[cuttin edge]

Makes sense. It looks like a fuel shut off on an Asian built generator, or pump, or even a snow blower.

 

[ksihota]

Yes, that looks like the drain for the fuel tank (to empty any water.) You might want to check your radiator cap to ensure it is not the issue. Mine was blowing out the overflow until I replaced the cap.

 

[td0g]

So my problem turned out to be that the lines to the heater core in the cab were leaking, There is a shut off on the top of the motor for these lines but it only shuts off the feed from the pump, so the hoses were still pressurised and leaking. I don't need the heater so I just got a length of hose and looped out the circuit. Now that the system is building pressure again I think I do also have a bad rad cap because the overflow is overflowing every time I use it it for an extended period. Do you happen to have the part number for the cap?

 

[ksihota]

Looks like the one I got was part #201-03-51310
Cost me about $37 CAD from the dealer

 

[td0g]

Thanks!

 

[John C.]

You can buy a radiator cap from any auto parts store for a lot less money. Just take yours in with you and match it up.

 

[td0g]

You can buy a radiator cap from any auto parts store for a lot less money. Just take yours in with you and match it up.

I did hit a couple places but the only ones I could find that fit were 1.1 BAR. The dealer cap was only $6 more than those anyway.