Does anybody pump a job with their air conditioning on, or do you turn it off like you are supposed to?  Can anybody explain why we are supposed to turn it off.

Mike

I shut it off.  I guess it prevents the engine from over working by not having to run the ac compressor. 

Funny thing, Friday my engine fan stopped working while setting up for a job, the Mack overheated and shut itself down.  After idling for a few minutes without the PTO engage it cooled off.  I continued and it never heated up again....and the engine fan started to work again, finished the job. 

Hey der did you check your coolent level. That will cause the Mack to shut down if you are to low.

Russ

Russ:  That was the first thing I checked.  It took maybe a gallon, and that was it.  Seems to me, maybe I'm wrong, it shouldn't overheat or shut down with only a gallon low.  I think it was a glitch and the fan didn't kick on, it then overheated and shut down....the temp gage was reading real hot....over 230.  Would it overheat and shut down with only a gallon low???  Therefore, I believe the fan was the problem.  I was standing in front of the truck, close to the bumper and the engine fan wasn't on....I will have to chase wires monday am and look for a short.

personally, as a mechanic, I like for our guys to turn the AC off when pumping. Mainly because the more you run it, the faster it will break. It could also possibly cause an overheating prob. for the engine due to excess stress load on the motor. Most guys like to keep it on so that the cab stays cool, and inbetween trucks they can sit in the cab and cool off, but my thing is, you shouldn't be sitting down resting in the cab, I like to stay right there at the hopper and keep an eye on the mud...because we all know what can happen when you turn your back for two seconds.

I've never heard this theory.     Who has heard of the Over the Road trucks shutting off the A/C to climb the hills?

I think that Mack has the cooling system designed to cool both engine at full load, and the A/C simultaneously.

But if there was a problem on my machine, yes I'd be the first to shut down the A/C

Theory....it has a warning sticker right on the doghouse to turn off air when pumping.  Personally if my job is only 2-3 hours I leave it on, but if I get a long job I will turn it off and when I go to wash out I turn it on and the cab is nice when I get done.

Ya know I just thought of something, that sticker is not on our telebelt.  Wonder what the difference is or mabey sombody just removed it.

I have a 00 tb 105 and the sticker is next to the ac control. terry

Kind of off topic but does anyone have their windows tinted on their pumps??? my a/c isnt cooling off so i thought about tinting the side windows and the back one

We had our side and back windows tinted in our 28m and it was not a good thing. Yes it kept the cab cooler but you could not see a damn thing out of those windows at night. If for some reason you are driving with the windows open, because of the slide forward design on the macks it is really hard to see cause of the double tinted windows on top of each other. Besides I think it is against DOT regulations to have the side windows tinted on any DOT vehicle. I am thinking of blacking out my rear window next rain day. You can't see anything out of it anyway might as well make it dark.

One operator once told me during summer a certain concrete pump manufacturer recommends the air conditioning be in operation otherwise pump remote electronics heat up and shut down the unit.

and they said that you could have them tinted but had to have 80% light shining through the side windows. And there was no rules on the back one or the small window by the passenger floorboard. Also they said you could have so many inches of the front one tinted. I was just curious if anyone else did it. I limo tinted the little one in the floorboard and it looked really good. but i put some tint on one of the side windows, it was 35% and you couldnt even tell it was on there.

sorry i accedintally deleted the first part. it said "I called the place where we get our DOT inspections and they said"

MM36Z

I was told that the truck, while stationary, did not have enough air flow over the coils.

I would think that this may or not be true but......... the guy that said if it wasn't on it would last longer said it all ;~)

Theidea of not running the ac while pumping came from mack. Back around '95 they had a problem with belts not staying on. The theory was that the surge of the pump and the ac comp turning on and off was causeing the belt to fail..

And it saves fuel not running the ac

I remember the belt problem; that makes sense.

I would think running a/c while pumping be a BIG STRAIN on charging(batteries and alternator) as takes quite bit of juice for remote. Sure dont wanna lose alternator in middle of pour!!!

I lost my alternator in the middle of a pour this past February, the snow was falling, it was miserably cold, muddy, wet, and lo and behold, between mixer trucks I jumped into the cab and noticed my alternator was reading real low.  I wasn't sure if it was a bad alt problem or just a gage problem.  After taking a reading with my multimeter, I realized I was losing battery voltage.  I couldn't get a vehicle close to the battery box on the pump truck (to run jumper boost cables to it), so we got a honda generator and connected it to a battery charger.  Worked great, finished the job.