Automotive Air Conditioning Information Forum

This is a dual a/c system with 60 oz capacity. Vacuumed for 2 hours and charged from a heated drum. After taking in 28 oz, it wouldn't take any more even when reving the engine. Gauges were in the 35-40 and 150-175 range. Air is blowing cold but why can't I put in a full charge? The tank weighs about 14 pounds. Shouldn't that be enough for good flow? Charging tank upright.

I would have charged liquid thru the high side with engine off, then top off on low side if needed when running.

What work was done to the system?
Ambient?
What are vent temps?
Is there a blockage to the rear system?
Feel the low side lines coming from both evaps to check for cool/cold

Truck has been sitting a year and a half and nothing done to it.
90°F
Didn't check with a thermometer but fairly cold
Rear is cold too.

Can I continue adding as a liquid to the low side?

NO!!!!!!!!

Don't even think of it. You will grenade the comp. You have been on here before, you already know the drill.

Truck sitting for a year? Leaks? anything apart?
I would have changed the filter dryer after leaks were fixed, pulled at least a 2 hr vacuum, then recharged.
Since you didn't pull a fresh deep vacuum, it would be difficult to get all the charge in.
There is more to this story than we are hearing.
And when giving vent temps you need to use a thermometer, please

tbirdtbird wrote: ↑Wed Jul 20, 2022 3:54 pm NO!!!!!!!!

Don't even think of it. You will grenade the comp.

Why will it grenade the comp now, charging with liquid on the low side, when you first said, I would have charged liquid thru the high side with engine off, then top off on low side if needed when running.

Had nothing apart, seals dried out and shrunk while sitting. Once coated with oil they should seal better. And I DID pull a 2 hr vacuum after waiting 15 minutes to see if the vacuum would drop which it didn't.

I should have been more explicit....what I should have said was i will top off if needed on the low side with VAPOR.
VAPOR goes in low side comp running, LIQUID in high side engine off. Sorry for the confusion. Do not confuse these two

OK

atikovi wrote: ↑Wed Jul 20, 2022 1:10 pm This is a dual a/c system with 60 oz capacity.

The information that I have, for all 2003 Ford E-series vehicles, all engines, with rear A/C, specifies 64 ounces net weight of R-134a, and 13 fluid ounces of PAG-46. But maybe you're seeing 60 ounces on an under-hood decal, which takes precedence.

atikovi wrote: ↑Wed Jul 20, 2022 1:10 pm After taking in 28 oz, it wouldn't take any more even when reving the engine. Gauges were in the 35-40 and 150-175 range. Air is blowing cold but why can't I put in a full charge? The tank weighs about 14 pounds. Shouldn't that be enough for good flow? Charging tank upright.

Have you checked all your charging/testing apparatus to ensure it's working right?

A few potential issues come to mind that might be causing this:
—A valve seal inside your Manifold gauge Set (MGS) might have broken off and blocked the low-side valve, quick-connect adapter, and/or hose.
—If the yellow hose has a check valve on its charging-cylinder end, it could have suddenly stuck shut or broken, preventing the refrigerant from flowing.
—Check all of the hose sealing rings/o-rings/gaskets as well. A piece might have come off one of them and blocked a hose. Try blowing some pressure through your MGS and all your hoses while disconnected from the vehicle to determine whether they're flowing freely.
—Quickly open and close the charging-cylinder valve without the yellow hose connected to it to ensure refrigerant is flowing freely.

atikovi wrote: ↑Wed Jul 20, 2022 1:10 pm After taking in 28 oz, it wouldn't take any more even when reving the engine.

Update. After getting a new tank, I tried adding the additional 32 oz, and it took it just fine. I guess the original tank was too low. Air is nice and much colder now.

Great news...thanks for updating us.