6.4 AC improvement

lariat08 · Aug 31, 2016

I have an 08 6.4 and I'm wanting to know if I can use the AC Pro stuff found in most stores? If so where in the world is the tube that I can plug it in to? Any advice would help....

mikeeg02 · Aug 31, 2016

Are you having an issue with your A/C? In my experience, the best way to do anything to your A/C is evacuate it for at least an hour, the longer the better, and put in EXACTLY as much as it says on the hood or the sticker in the engine bay. Going off of pressures will get you close, but there are a whole lot of other factors that go into it. IE outdoor temperature, humidity, airflow through the condenser.

lariat08 · Aug 31, 2016

mikeeg02 said:
Are you having an issue with your A/C? In my experience, the best way to do anything to your A/C is evacuate it for at least an hour, the longer the better, and put in EXACTLY as much as it says on the hood or the sticker in the engine bay. Going off of pressures will get you close, but there are a whole lot of other factors that go into it. IE outdoor temperature, humidity, airflow through the condenser.

I dont feel like its an issue but it is starting to taper off a little bit in regards to performance. I was just looking for a temporary fix for now. Just wanted to knowing I could use it on my truck or not.

mikeeg02 · Aug 31, 2016

I can look at out 6.4 at the shop tomorrow and find the port, but your best bet is to put a set of gauges on it and see if its within specs. If it is, your best bet is to evacuate it, and make sure you can pull and hold a vacuum (to check for leaks) and then refill. Its generally a good idea when doing this to replace the drier, as its the filter. And if your going that far replace the orifice tube. Then make sure it pulls a good vacuum. If your pressures are low, you probably should replace the compressor and all of the above.

When is it an issue? Sitting idle? Running down the road?

webb06 · Aug 31, 2016

Low side port is behind the air intake box. Under the pcm.

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lariat08 · Aug 31, 2016

Normally blows somewhat warm while idle. Once I get going it's not bad. Thanks for the info. Its something I can look in to a little later down the road.

f350guy · Sep 1, 2016

That **** in a can is just 134A and some other garbage with an expensive price and cheap-ass gauge. Skip it and diagnose the system correctly as others said....you really do not want a blend of junk in the system nor do you want any stop leak. If you do not have a good manifold set (not a Harbor Freight set) and know the basics, take it to a good shop for an evac, vac, recharge to spec. Factory 134A systems have pretty low capacities on charge normally as they are very efficient, so it should not be very expensive to have it done.

There are many reasons vent temps can rise at idle...

Dirty condenser (or IC blocking the condenser from heat transfer)
Recycle door not closed
Fan clutch dying/dead
Coolant running through heater core when not commanded

Check the usual suspects first, then if all that is up to par, drop it off at a quality shop with a commercial recovery machine.

capt dong · Sep 2, 2016

Check pressures before you charge. You may overcharge and damage more parts. Sounds like you have a clogged condenser.

tbsimmons · Sep 2, 2016

Like above for diagnosing but the 6.4 I never felt had a good AC in it.
Better than the 6.0 trucks but not as good as the 6.7 which is still not as good as the GM trucks. Every GM I have been in has had a great AC.

But like posted check those pressures and don't trust the cheap store bought AC in a can. It could be that you are low on freon, yes but it could also mean that one of the lines is plugging and the high side switch is shutting everything down.

6.4f350 · Sep 2, 2016

I had my AC vac'd down and refilled at a buddy's shop after putting the motor back in and even since then my AC has been ice cold. It will freeze you out of the truck. It was never like that before.

tbsimmons · Sep 2, 2016

Maybe the weather is different. I could never get it that cold. The GMs I have had would get in the low 40's high 30's the Fords were in the mid 40's low 50's even at idle.

Izzybird · Sep 2, 2016

Like mentioned, get some gauges on it and see what's going on. The old 7.3 work truck started getting in the mid 50's at idle. Vacuumed it down, orifice tube screen was clogged big time. Threw a new one in figuring the system would shlt the bed soon and I'd just replace everything at that point. That was 6 years ago of humid Central Texas summers. Blows about 42*