Air conditioning

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Wesley0620

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I have a 1987 R10 1/2 ton pickup I put a new compressor, drier(accumulator), orifice tube, condenser flushed out system vacuumed down but my problem is I have really high side pressure (350 before I unplug the compressor) and really low side pressure the evaporator blows open when I flushed and cleaned it I am at my wits end evaporator is the only thing not replaced except I still have the original hoses any help at all
 

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Is the orifice tube full of crap?
 

Vbb199

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Excessive high side pressures can be a result of a few things.

Non-condensables in the system.

Definition:
Non-condensables are gases that will not condense into a liquid within the operating temperatures of the refrigeration system. Air and nitrogen are the most likely non-condensables you will see.


Secondly, debris in the system will cause excess high side pressures

3rd, a wearing/aging compressor will display higher than normal pressures. (Not your case)


What freon did you use? Which compressor oil?

What was in the system before?
Did you purge all the r12 out if you did a r134a swap?

What was the final vacuum in/hg before filling the system up with freon?
 

CRM

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How long did you leave the system in a vacuum after turning off the vacuum pump (with the gauges closed off)? When you charged the system did you bleed the air out of the charging hose first? Air, and moisture in the air, can cause issues like high head pressure (the air sits at the top of the condenser coil) and low suction pressure (the moisture freezes in the metering device).
 

Wesley0620

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No the orifice tube is also brand new and my vacuum was showing 29in/hg I let the pump vacuum for 90 minutes when I started introducing the R134a. Yes the complete system was flushed before I installed the new compressor and condenser and dryer and orifice I cleaned with a good flush kit the evaporator blows air through doesn't have a blockage as far as I can tell
 

Trucksareforwork

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Yeah. Sounds to me like you may have missed some crud that got to your orifice tube. Is there any chance you didn’t blow out the lines from the condenser to the orifice tube completely while flushing? You said you flushed the parts but did you flush the hard line ahead of the orifice tube?

Did you follow with dry air to clean out all the flush?

I just went through a head pressure issue on my son’s ford and it was definitely a clogged orifice tube.
 

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At the end of the 90 minute evacuation did you close off the gauges and see if it held a vacuum for 30-60 minutes? There's no such thing as dry air when it comes to a sealed refrigerant system. Nitrogen or CO2 only. Was the flush done after the new orifice was installed or before?
 

Wesley0620

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I left the system in a vacuum overnight and it held it and yes I opened the yellow hose at the gauge and purged the air in the line out there is no air in the system as I add R134a the high side just keeps climbing
 

Wesley0620

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The flush was done when the system was completely open no orifice no compressor and after vaccuming it held the vacuum all night
 

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Assuming the new compressor is good, low suction is due to poor airflow across the evaporator, a restriction, or low charge. High pressure is due to non-condensables in the system, poor air flow across the condenser, a restriction in the condenser, or overcharge. Did you weigh in the charge?
 

Bextreme04

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Have you tried spraying the condenser down with water while it's running? I agree with everyone else here, it really sounds like a clog somewhere. If spraying down the condenser doesn't change anything, then you are going to have to pull it back down and check your orifice tube.
 

Wesley0620

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Compressor is new and I only have about 1 and a half 12 oz cans in it I put a large fan in front of the new condenser and have had it apart several times and have replaced the orifice twice neither orifice was clogged or at the least bit dirty looking I have not opened the evaporator box to see if there was leaves or just accumulated dirt around it could that cause my problem
 

Bextreme04

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Compressor is new and I only have about 1 and a half 12 oz cans in it I put a large fan in front of the new condenser and have had it apart several times and have replaced the orifice twice neither orifice was clogged or at the least bit dirty looking I have not opened the evaporator box to see if there was leaves or just accumulated dirt around it could that cause my problem
When you "flushed" the components, did you blow compressed air through all of the lines to make sure it was free flowing? You have the orifice tube inserted the right way? Low suction makes sense with only 1-1/2 cans in it... although it shouldn't be super low.

Are you seeing a clear line where you have hot fluid before the orifice tube and cold/condensation after the orifice tube? What color tube are you running?
 

Wesley0620

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Yes blew both ways through the evaporator and had the lines off and blew through them I am using a Chevy white orifice the new compressor said use PAG150 and this system doesn't have a glass to see the freon could the oil be too thick
 

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