Cat 568 heater issue

[Hallback]

Blower motor is working, there is plenty of coolant in the system and heater hoses are warm but there is no heat coming out of the ducting. Does anybody know the part number for the actuator which controls the blend door?

 

[John C.]

I used to see the ones on the excavators just packed full of dirt. I had them clean out the ducting and things went to working again. I think you have to take the seat loose and tip it over the travel handles to get access to heater unit. Your machine isn't a rear entry cab is it?

 

[Hallback]

No, side entry.

 

[John C.]

Unless there is a difference between a ROPS cab and the older excavator units, I think it should be the same AC system.

 

[Hallback]

Yes, it's all electronic. Should be part # 265-9620

 

[hoechucker]

It's usually the other way with cats. Heat works fine but no AC.

 

[John C.]

Since the heater and cooling coils are in the same basic can, I note it all as the air conditioning system. I guess climate control would be a better description now that I think about it.

 

[Hallback]

It's usually the other way with cats. Heat works fine but no AC.

Yes, we call those "Cat flashes".

 

[Hallback]

So I put that actuator in and no luck. I tilted the cab down and could see where somebody had cut the heater hoses at 1 time and put a splice in each one in the same location. I pulled the hose apart there and blew through it with air and added more coolant to replace what I lost.
It produced heat for that day and now it is not again. Is there a possibility that something is in the heater core plugging it up or is there a chance that the heat/ac switch is faulty? I notice it only lights up on A/C and not in heat mode.

 

[heymccall]

I dont know what that exact system looks like, but, on my cat 330 machines (can't remember if they were B's or C's), the actuator would collect condensation followed by over running, shearing the blend door shaft.

So, with that said, are both pipes warm at the heater core?
When you changed the actuator, did you verify that the door actually moves?
Doesn't that system sweep all the actuators at startup?
Do they all sweep?
Can you get codes from the hvac controller?

 

[John C.]

It sounds like you have a raised tilting cab of a regular shovel. Make sure the radiator cap is good. Get a 14 pound one from a Napa dealer and throw away the crap one that comes from Cat.

 

[heymccall]

?

 

[Vetech63]

When I have a suspected a clogged heater core, I have switched the hoses and let the flow run the opposite direction for awhile. When it unplugs flush the system. It has worked numerous times for me.