On a 90 to 95 degree day my dozer will blow about 65 degrees out of the vent in the cab. Its a 39 Komatsu -21A. Lots of glass. That is a 30 degree drop , I think that's doing pretty good but wanted to see what others had recorded. It gets warm feeling in the cab in the afternoon when its hottest , which I guess is natural but in the am and evening you can turn the fan down as it gets cool feeling. I've seen dozers with window tint , I guess this helps mid afternoon temps. One reason I ask , my F250 will blow 45 degrees in the afternoon. If it needs a shot of gas or wash out condenser and evaporator I'd like to do so to avoid a compressor failure.
I would clean the condenser first, and check to see if the fan is working right. My JD has two fans on the condenser and one quit, it would get warm in the cab blowing 70 degree air.
Window tint goes a long way but challenging to install correctly. I've been wanting to tint the windows on my 953 and 420D but haven't got around to it. Plus the weather will change in a month, I'm a master of procrastination.
Make sure the in cab filter is clean and the evaporator is clean as well. That won't make it blow warm but will slow down the air flow and hinder the cooling
1/3 throttle in neutral it should pull down to 45 degrees f but if idling won't go much lower than 65 I'd imagine
I'm going to blow out the filters in the morning , and check on washing the evaporator and condenser as well. Trust me on this if you think its warm inside , and get out to take some grade shots you soon find your way back inside. Only concern I had was the actual temp coming out of the vents. 65 seemed a little warm in comparison to others. I did replace the air filters about 100 hrs ago maybe more , but it did get fairly dusty in the past few weeks . One question , should it be on recirculate or outside air in?
Recirc
Thirty degrees is fine. Machines don't have all the insulation of a car or truck. I would tint your windows, it will make a huge difference in the cab temp.
Tint the windows. You won't regret it. I also added curtains on the side windows. Yes .....curtains. It is worth the ribbing you'll get. :drinkup
Blew the filters out , I put new ones in about 50 hours ago. Needless to say they were pretty well plugged. I haven't been back to machine to put them back in yet. You can see the evaporator when you remove the main filter , it looked to have some dust on it not much. It was making a lot of condensation. Also it has a site glass on the filter drier , it shows liquid only , no bubbles so I think charge is ok. Its been as hot in the last two weeks as its been all summer as well. I'm going to order 2 extra sets of filters , and try to change them once a week or at least inspect for cleanliness. Thanks for all the input , this is my first cab machine , and I want to keep everything working properly.
I'm not familiar with the Komatsu A/C filters but we regularly blow out the cat filters. I wouldn't change them so often if the filters can take the air blowing and you can get them somewhat clean, as they're going to plug right back up again.
CM , I'm getting the other filters to put in a rotation , I don't have compressed air on my truck. I can blow them out at the shop and keep extras with me. I was told these machines eat compressors , but I feel like that's due to lack of maintenance. We had an HVAC , plumbing and excavating business at one time , I went on to pursue the excavation part so I'm familiar with what happens to a poorly maintained a/c unit.
We have 4 komatsu dozers and they seem to be harder on compressors than our other machines
There is a company called Cool Pro from Fort worth , Tx . They make/sell AC parts. Not sure which compressor your Dozer uses. But they sell an updated compressor for older John Deere tractors. These tractors came with a GM A-6 compressor and they sell a S-6 direct replacement compressor. The old A-6 compressors were designed for R-12 and the S-6 is designed for R-134 . They may make a better compressor for your dozer. Hope this helps
Dickjr. check that the heater valve is actually closing all of the way. If this is not happening some of the cool air from the evaporator is warming up a bit. If it has manual heater valve(s) close them and see if it makes a difference. I have no experience with komatsu dozers.....TIO
Put in the new filters today and the vent temp dropped to 50*. Considering it was 95 with a heat index of 100 , I believe its doing all it can do. As I said in a previous post , lack of maintenance always seemed to be an issue on air cons. This time it was on me. The "new filters" I put in probably had 100 plus hours on them , just installed a few weeks ago. Hopefully we may have saved a few compressors by all this.