I have a 1997 F-150 that all of a sudden lost its coolness...(well on the inside that is). It's a sweet ride on the outside!

A/C not cooling. Here is what I have done so far

- Added one can of R-134. (The one with the stop leak in it) That worked for a day and then it went back to the same

- Added another can, this time with the combination stop leak, pag oil and red dye. This time it did not cool so well and within a day was not cooling at all.

- I checked for leaks and I cannot see any dye anywhere. I checked the motor while it was running with A/C switch at max and I can see the A/C compressor moving as the clutch engages. It goes on for about 2 seconds then goes off. Then on. Then off...

Pressure on the high side before adding refrigerant was 100psi. After adding one can it was 150.

The only unusual thing I did see was after adding the second can and running it for about 20 minutes, there was a lot of water under the vehicle. I know some condensation is normal but this was about twice what I would normally see. I smelled it and it did not have any odor. It did not feel oily. There was no red dye in it. I am sorry but I did not taste it

As you know it is about 90 degrees in the daytime here in Hawaii, the truck is black and my daughter drives it and she is a princess. Daddy needs to be a hero here. Please help!

 

I use to run into this issue with an Aerostar I use to own and the issue was resolved by using the tall cans of R134 with the gauge on top. It might take a bit because what it sounds like is the system is not having enough coolent to dispense, thus the clutch engauging then disengauging. You'll also need to look up and see what the capacity of the system is so you know how many cans to buy. Not sure how to check what the current level of the system is though.

Also I know it sounds odd but what is your radiator tank level? On my 98 f150 if the tank isn't full where it's supose to be the a/c blows warm to hot.

Just my two cents on the matter,
Matt

 

Go read the HVAC faqs. Link is in signature below.

 

Topped off coolant and put 3 cans of 134 in the system. Blowing snowballs now! Will run it a few days and report back if it worked

 

the two second cycle time is a dead give away. Your running out of coolant on the suction side and the low pressure switch is tripping off. AT 90 degrees, I would think the HP end would be above 150 psi. The low side needs to be over 30, maybe closer to 40 psi.... you were low on gas, the question is "where did it go"... hopefully the sealer will plug a small leak somewhere.

 

It stayed cold for a few days and now its back to doing the same thing. I put a can of the refrigerant that has the red dye in it but cannot see any red anywhere. Do I need a special light for that?

The only other thing I noticed was that instead of the minor drips that cars leave when the A/C is on while parked, this one left a big puddle. Would that mean that the evaporator may be leaking? I don't want to change the whole system. I would rather chase the leak and fix only what I need to

 

I had one I could never find the leak. Had just a small weep on the HP port valve... Later I added a can with the sealer in it, and that fixed the problem. I was no fan of sealer products, but it did help this air conditioner... and I looked hard for the leak !

 

put some refrigerant in and let it idle. put a cup underneath the evaporator drain to see if there is dye in the water. if so then your evaporator is leaking.