AC Problems!!!!!!

[lkub65]

Hello, we are having a problem with my husband's 2002 F250 and I am hoping someone here might have an answer. When ever he stops at a red light or something he has to power brake the truck to keep the rpm's up so the air conditioner will blow cold. If he doesn't it seems as though the air is blowing across the heater core and blows hot air. We have put gauges on in and they read that his freon level is in the normal range. I think it sounds like a vacuum leak but since diesel's don't create vacuum it has to have a vacuum pump. Does this sound like it could be the problem and if so does any one know where the vacuum pump would be????? Need help soon or he will have the entire truck in pieces in the driveway.........

[pipelayerjdh]

The vaccum pump is under the PS pump on mine, not sure on SD's but it will be there close. Try tracing the vaccum line under the passenger side of the dash.

[smokeshow101]

Try checkin your coolant level.

[Bronconut]

I'm having a similar problem..thought it might be the a/c vent door, but dont know where it is?

[jfines@cox.net]

If it were a vaccum problem, it would not change how cold the air is. The air will come out of a different vent (ie:defrost).

If the RPM's have to be higher then I would check the condenser up by the radiator, and make sure there is no debree in the way. After that I would check the fan clutch.

[super_stroke]

vacum pump is located on pass. side innerfender. open the hood and turn the key to run and it will run for a few second's, just listen for it and you can find it. your problem could be related toi a bad pressure cycling switch, low refrigerant or a failing compressor. also, like was said before, make sure the condenser (in front of radiator) fin's are as straight as possible and clean. if it look's a little dirty, lowe's sells some cleaner for air conditioner's called coil cleaner, that will clean the dirt, dust and road grim out of it. here at home it's in the lawn and garden section. ask them for it.

[WILLIAM LORCH]

Dont believe the vacume pump , U need that 4 the power brakes to work!!! Check the compresser for the A/C , Look 4 shinney oil suff near the front of the compresser behind the pulley.. It is about time for the compresser to give out if you have an '02, Thes compressers (Nippendensa), are short lived things. Im not sure y but i have a feeling its engeneered in. Anyway this is a good start... DOES the blower motor run at the same speed ???? The A/C evprator and hte heeter coils are in hte same aera and found on the passengers side of the firewall ,the blower motor is the smae place. If you can have some one look at the operating arm of the vacume chamber found near hte top of this aera, and b sure the door is closing... Good luck Bill

[Super Kaz]

Yea, my truck does the samething. Blow ice cold while driving, idling it get warm. I'd like to know what you find the cause this. I have no leaks and the blower blow fine.

[sirnunya]

I had the same problem kinda. fixed it by replacing the low pressure switch and taking a shim out of the compressor clutch. I would try the low pressure switch first..

[djordan1184]

Originally Posted by Super Kaz

Yea, my truck does the samething. Blow ice cold while driving, idling it get warm. I'd like to know what you find the cause this. I have no leaks and the blower blow fine.

Mines different on my 06 6.0.At idle it blows very cold but when driving I have to keep my gage on max.Now it still blow cool air while driving but not cold.scott put the extra 1/2lb in it when he had it but it still does the same thing.