Ac low side pulling a vacuum
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Trailering
Joined: Jan 2021
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Ac low side pulling a vacuum
2006 f250 with 5.4 triton , replaced orifice tube and low pressure switch on the ac. Pulled a vacuum 28lbs and held it for 10 min or so . no leaks in system . It calls for 34 oz’s of Freon , Put in 2 12 oz cans refrigerant and 1 3 oz can if oil, stop leak and ice in the system, I pretty much stopped at that point, my low side pressure was at a -13lbs vacuum and the high side was at 300lbs and air was still blowing hot . Why was low side pulling a vacuum . While filling the system I was getting somewhere around 3bs on low side but as soon as can would run out it would drop to the vacuum . What is going on . And how do I fix this
Hotshot
Joined: Jan 2004
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From: St Louis
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Trailering
Joined: Jan 2021
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that was what I was thinking, went out and got a ac flush kit and more Freon and pag oil. Gonna flush out the evap and install another orifice tube and charge up again . Wish me luck lol
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Trailering
Joined: Jan 2021
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Well that didn’t fix it , after flushing the evaporator out and pulling a vacuum for 30 min I put in 33-35 oz of Freon while I was putting it in the pressure was at 45 low side 350 on the hi side , as soon as I finished the low side slowly dropped down to a -3 vacuum . I replaced the orifice tube again also . On the back side of the orifice (closest to evap) the line had frost on it but the large line coming out was not cold and the air wasn’t cold . Is that Saying the evap is plugged even after I flushed it ? Or is it something else plugged ?
Tuned
Joined: Feb 2010
Posts: 277
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From: Western Montana
Sounds like the blockage is somewhere else. Why did you replace the orifice tube in the first place? AC pump quit working?
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Hotshot
Joined: Jan 2004
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From: St Louis
Check the condenser for an internal blockage.
The previous post has questions that are important. Also, what was the condition of the original orifice tube when it was removed?
The previous post has questions that are important. Also, what was the condition of the original orifice tube when it was removed?
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Trailering
Joined: Jan 2021
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i originally thought that it was what was plugged up and it was a cheap 4$ part so I figured I would change it out since I would have the system open anyway
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Trailering
Joined: Jan 2021
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Tuned
Joined: Dec 2017
Posts: 293
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From: Houston
Never use "stop leak" in any Freon based AC system. System will need to be purged or replaced.
Lead Driver
Joined: Nov 2020
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From: Sportsman's Paradise
I've seen it before is why I asked and that green you see is factory installed leak detector. You've got a blockage somewhere in the system.