01 Superduty A/C issue

[errinjan]

Hello, my 250 Supercrew Lariat just left the shop. They added 1 lb of refrigerant and sent me on my way.
But I still have the same issue.
A/C will preform quite well (43 degrees according to the tech) for several minutes to a couple of hours. Then you get odd smell (musty) followed by very humid warm air.
If I'm on the highway, I can disengage the overdrive. That will re-start the cold air flow.
In town I have to down shift to a lower gear.
Sitting still, I can put it in neutral and blip the throttle once or twice.

The tech is baffled, any ideas

thanks

[enoyes12]

Mine does the same thing. Have him check the pressure switch. I'm going to replace mine and see if it fixes it. When I'm turning less than 1500 RPM mine does it more often

[errinjan]

Just found this other thread that may solve the issue. here's the link
A/C Problem

They say the compressor clutch has adjustable shims, could be a drive way fix I HOPE

sorry for the re-post
I searched for a answer before I started a new thread. Must be in the spelling or the lack there of on my part

[enoyes12]

I forgot about the clutch shim. Yeah not supposed to be a big deal to fix. Definately a driveway fix

[tony66]

I have heard that on a chevy (might be the same on the Ford) that when you get too low on fuel the computer will turn off the A/C to save fuel.

[errinjan]

Well here's the update, it worked!
When I got it off there was only 1 shim, it measured .0040
Our only option was to use a emery stone
We sanded it down to .0035
Put it back together, it seems to have fixed it.
I did go the O'Reilly, I ordered a shim kit (6 shims-I assume various thicknesses, 1 bolt) for $15 I pick it up this morning.
I' m going to replace the sanded down shim with a .0025 or .0030
I will post the kit # when i get it.

THIS FORUM ROCKS

[errinjan]

The kit from O'Reilly is
Murray #24187
.057
.043
.032
.018
.014
There are 5 shims total + 1-8mm bolt
and 1 snap ring (I don't know anything about it or what it's for)