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Old 08-17-2017, 08:44 PM
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ps2cho ps2cho is offline
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Join Date: Jun 2006
Location: Chandler, Arizona
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Quote:
Originally Posted by engatwork View Post
is the electric fan at the condenser blowing wide open during the time you are getting the hi reading?
Quote:
Originally Posted by Diseasel300 View Post
Have you bothered to deal with airflow across the condenser? If not, your pressures are arbitrary and meaningless. The system pressures will continue to vary with load and with the amount of refrigerant in the system. Even if you keep adding refrigerant, the head pressure isn't likely to rise very quickly as the liquid begins to fill the condenser.

Charge by weight (80% of the R12 weight) and THEN check pressures with a fan blowing across the condenser. At 105˚ and a high load on the system, your pressures will be high. My SDL runs ~350-360/55-60 at the same temps with the fan on high and all 4 windows down. Once the cabin pulls down to temp, the pressures drop dramatically, more along the lines of 250-275/30-35.

Load and airflow matter when measuring pressure. This is why you charge by weight.
Yes. I have dual SPAL HD fans that I swapped in place of the stock single fan running maxed out with addition of a big garage box fan. The aux fan is locked during this time.
When I charge by weight, I hit 60/420+ psi. Its not a refrigerant issue here. A few years ago I had a local A/C shop evac and recharge and he said pressures were too high, but just shrug and said must be the r134a, which I do not agree with. Somethings off and I believe its oil related, but still have not had anybody tell me if this could be true.
These pressures are BEFORE engine heat soak.
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