AC high pressure too high
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AC high pressure too high
AC worked fine last year. This year it is not cold. Some cooling but not cold. Assuming refrigerant leak, I connected gauge, turned on AC, and measured pressure. High was going above 300 when low was coming down toward 40. When high reached 350 and still going up, I cut off AC.
Google search says something is blocked. Condenser, orifice, or tubing I suppose. I am ready to take the truck to AC shop for refrigerant recovery. Let me just ask one question. If the blender door is stuck and fail to direct air flow to evaporator, can it cause the pressure reading? The blender door actuator was replaced last year because of heating problem.
Thank you.
FYI: Truck was purchased in 2004 @48K miles. I haven't replaced any AC parts. No sign of refrigerant leak (no wetness).
Google search says something is blocked. Condenser, orifice, or tubing I suppose. I am ready to take the truck to AC shop for refrigerant recovery. Let me just ask one question. If the blender door is stuck and fail to direct air flow to evaporator, can it cause the pressure reading? The blender door actuator was replaced last year because of heating problem.
Thank you.
FYI: Truck was purchased in 2004 @48K miles. I haven't replaced any AC parts. No sign of refrigerant leak (no wetness).
Hotshot
Joined: Jan 2004
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From: St Louis
If the blender door is stuck and fail to direct air flow to evaporator, can it cause the pressure reading?
Leave the refrigerant alone for a bit. There's stuff to be checked before going down that trail to make sure you're not following a rabbit.
Verify that the engine cooling fan is actually pulling enough air through the condenser coil. If either the fan clutch is worn out (or dead electric fans) or the external coil is clogged with dirt or debris, there will be insufficient heat rejection and the high side pressure will skyrocket. If everything "looks" good, hit the condenser with cold water from a garden hose while attempting to operate the system. If the high side pressure drops back into the normal range when sprayed, then you have your answer as to where to focus efforts.
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The condenser didn't look too dirty or clogged. But I blew the fins with compressed air and washed with garden hose. That did the trick. Steve was right on the money.....clean even if it looks clean. Pressures are now 29 Lo and 175 Hi @ 75 F. According to the chart on internet, 35-45 Lo and 150-170 Hi @ 75. Do my numbers indicate some level of flow restriction? Thank you gentlemen for saving me from the trouble of AC surgery.
EDIT: Different source (Lo & Hi)
No issues: 30 & 200
Undercharge: 20 & 100
Overcharge or air in system: 40 & 250
Weak compressor: 40 & 100.
According to this source, my AC has no issues.
EDIT: Different source (Lo & Hi)
No issues: 30 & 200
Undercharge: 20 & 100
Overcharge or air in system: 40 & 250
Weak compressor: 40 & 100.
According to this source, my AC has no issues.
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