14H a.c.

[JCG74]

Anyone know exactly how cold the a.c. should blow in a 2006 14H motorgrader. Everything has been replaced with new CAT parts. I would be checking by placing a digital thermometer in vent closest to return. If it gets above 80 degrees outside I cook like a pop tart in the cab. Not looking forward to the coming summer. I remember running a 980 loader back in the 90's that would literally freeze me out. Why don't the a.c.'s work like that anymore??

 

[Cat 140M AWD]

I'd say your system is low on freon and that's why it's not freezing you out of the cab I had the same problem on my 140h and now it will get really cold in the cab.

 

[Nige]

Lots of things come to mind on a machine A/C system. You say "Everything has been replaced with new CAT parts" but what exactly has been replaced...?

I'm sure you have done all this already but there may be a few ideas for you anyway.

1. New fresh air and recirculation filters..?
2. Ducts in cab from blower fan clean and free internally from obstructions like plastic bags..? You wouldn't believe the cr@p we dig out of them. To make sure the ducts are totally clean usually means disassembly of the cab panelling.
3. Blower running at full speed. I've seen motors slow down when the brushes start to wear a bit.
4. External evaporator (condenser) completely clean. Is yours mounted on the roof or behind the cab..? Either way to clean it completely means it has to come off the machine.
5. Condenser fans working..?
6. In-line dryer (Ref. #2) replaced recently..? the dryer can be replaced without evacuating the system.
7. Accumulator (Ref. #6) in good condition..?

And all that before you even go near checking the gas charge ................

Your A/C should blow cold air out the vents at somewhere around 60degF if it's in good condition.

 

[Nige]

Got my numbers mixed up. Accumulator is #2, dryer is #6.........

 

[Randy Krieg]

We also shut off the coolant valves at the engine so no coolant (hot fluid) is flowing through the heater core. Too many times the temperature control dial in the cab doesn’t totally cutoff the coolant flow to the heater core. Just a small amount of hot coolant being allowed through the core defeats the purpose. We generally shut the valves off in May and turn them back on in September. If it doesn’t have shut off valves then install some, spigots or ball valves both work well.

 

[Nige]

Good point Randy. I forgot about that, possibly because our climate's so warm we run with the valves closed all the time ......
This is what appears to the the combined heater/Aircon lines for a 14H. The valve is Ref #8 in Area B of the graphic.

 

[Mobiltech]

Most of the ones I see that don't put out are due to the heater valve not closing completely or the evaporator core under the seat plugged with dirt. There is also a no freeze switch sensor with a tube inserted in the core that controls how cold the AC will get before it cycles the compressor. I have pulled the sensor tube out a bit on some to get it to run colder. The temp out the vents close to the core should be in the 40's F
You can open up a small inspection door on the rad to clean the condenser core too.

 

[HATCHEQUIP]

Don't forget the expansion valve