Just this week my AC has not been blowing ice cold just cool. Hooked up the gauge was in the -green(normal), figured I'll just top it off with freon. Three cans later, no improvement, now gauge reads -red(possible mechanical problem).

I'll try to clean the evaporator, I have read the thread-
Can the Air Controller be fixed?

Anyone with solutions, sugestions, Thanks. THIS TRUCK WON'T BEAT ME!:banghead:

Take your oriface out, better known as expansion tube... its located in the lower pipe of the condenser in the front...You will have to drain all of your gas out though... If its nasty replace it... If its full of metal get on your knees and pray to god! After you get all this done, put new o rings in it, put it all back together and pull a big vaccum on the system! THIS IS IMPORTIANT! Water vapor in the system will give you the symptoms your having. After you have your vaccum start the truck and charge to the green... THEN! have someone hold the engine RPM to where you normally drive it.. I charged mine a 2500RPM.... This way it gets cold where you want it! Be sure you have caps on all of your service ports... and when its charged check it for leaks! If this dont help, you may have to have a new accumulater/dryer. They do eventually crap out


Cleaning out your evaporator is a very good start though!

Cleaned the evaporator, slighty better(still not ice cold), and first start smell gone.

Which orafice tube should I get the auto-adjusting $25, or the reg $5?

And how do I pull vacume??


Thanks for the reply, sorry about the questions, only know how to charge AC's; also where's the spark plugs??:lol:

Get the regular one. The auto adjust doesn't do much except lighten your wallet. That is based on the one I installed years ago and posts on various a/c message boards.

I got a cheap, as in $15, venturi type of vacuum thingy from the hong kong junkyard (harbor freight). It pulls a 30" vacuum but you need a big compressor to keep it going.

I think I've got an idea on how to do this, but does anyone have a step by step-plan, so I don't miss anything. Thanks again.

Also another symptom is the compresser kicks on and off (like normal), when I first start the truck, but then stays on all the time.

could be your low pressure switch malfunctioning

I thought I would throw in my $.02. I had a similar problem a couple of years ago. Do you use this as a work truck or for junk collection on your front passenger seat or floor? I used to. There is an air intake down their up under the dash. Mine got some paper work up against it. Just a thought. I was cleaning it to take it in and have it checked and then while taking it to the shop it started working. No problems since.

...looking through the fog of being up 'till nearly 2am finishing up my 'amateur' ac repair... there is a web site (probably thousands) that I used as reference in this... project... first let me say I had the local yokel charge my system in May that lasted for almost 2mo. so I decided to 'fix' this beast... I have a deep vacuum pump and good guages and bought a new orfice valve (the local guy put in one from the wrong truck) and 6 cans of 134r... I found after looking everywhere I could see, some oil on the pressure switch on the 'dryer' and tightened that,... well, I had a can of leak/dye and after reading what the ac pros had to say decided to use it... since I had the v pump I pulled a vacuum for about 3hrs (both sides) this would have been done fairly early except I had to tie wrap the plastic coupler to make the pump work... it actually held -29.5" merc on the low side and -28.5" on both... O'kay, it'll have to do...I read that over filling the sys is really bad so I had cans of freon to get the right amount... I took a piece of pipe to hold the accel. pedal at 1500rpm, but the open exhaust made it so loud at 11pm I did it at idle... one can got the compressor going then in went the 'leak seal'... I have a meter with probes to meas temps and put one in the front middle and the top back ac vents with the sys on high/recer temps at start were in the mid 70's... using a water hose to cool the condenser and 5 cans later ( the sys takes 64oz and I put 5ea12oz cans + one 3oz of leak seal) really about 45 mins to fill and 20-30min to let it work a while it was 53degrees front and 55degress back(who knows what the error in the meter)... much better than my friend 'mr I have a tank of freon'
It took a lot of thought as I'm only the avg shade tree 'have a wrench' and the book on auto ac never made sense, but the web site (actually a forum) where real people asked the questions worked for me..

...and... 'she who controls all' (at my house)... can ride in the cool,... hey me too! it's been a little hot here in N Cen FLA...

No trash blocking the intake vent. Anyway to check LowP switch/sensor?

Is there a sight glass on the vehicle?:eek:

Went out to the truck and drained system fom 75psi to 55-60psi and its cold!!!

Reved up to 2000-2500 rpm pressure drops to Blue(normal). At idle its in the Yellow(May be Overcharged).

Is this normal or a good range??

Okay folks, A/C systems are not very forgiving.... you can ruin your compressor if not careful...

Here's some points for everyone to follow...

NEVER EVER EVER EVER ADD MORE REFRIGERANT THAN NAME PLATE CHARGE TO YOUR SYSTEM... EVER EVER EVER..... you will liquid slug the compressor once the accumulator fills up and destroy it. Mine grenaded from proper charge, but stuck expansion valve.

Harbour Frt vacuum thingy will not achieve enough vacuum to remove moisture from the system. Non-condensables yes, (that's air, etc) but moisture no.

Don't charge by feel. Charge by weight into the system to the proper refrigerant charge. Perferably from vacuum state. Insufficent and excessive charge will give you both the same symptoms of lack-of-cooling.

Engine RPM, pressures, cycle times, etc, are all out the window because of all the different variables. You have fan speed, air flow, recirculate/fresh air, enthalpy/humidity, etc, that will all effect everything. No hard in stone way to know you are right except proper weighed in charge.

Complete details are found in this thread (http://dieselplace.com/forum/showthread.php?t=70563).

Did I mention... never over charge the system?

...there's a lot of good knowledge in that link 'knkreb', for about 2 weeks I must have read and studied everything I could find on auto ac (except the book I bought,... just couldn't follow it) and it paid off royally...

this weekend I am towing my TT south to FT Myers and I know it would be 'hot and sweaty' without ac...

the only way I could get a measured charge was with the cans, as 1) I don't have a 30lb tank and 2)it really is easier to get the correct amount that way (in my backyard)

next is taking the radiator out to clean it,... oh I cleaned it as good as I can with it in the truck, but I think it really needs to taken out and cleaned...