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High suction pressure and high head due to overfeeding expansion valve?
Posted: Sat May 27, 2017 2:13 am
by Swedal
Did a AC job a Saab 9-5 today. Was low on ref so pulled a vacuum and weighted in the correct charge for it. Still did not work ok. Head was somewhat high at 225 psi for 75 ambient and the suction was way high at 60 psi. Fans working and condenser is clean. It's not over charged so could this be a stuck open expansion valve or something with the variable deplacement compressor thingy?
Re: High suction pressure and high head due to overfeeding expansion valve?
Posted: Sat May 27, 2017 4:56 am
by Dougflas
Test the TXV. Pull the bulb loose and place it into a glass of crushed ice and water. Does the pressure change? Then hold the bulb in your hand. Does the pressure change? Yes, you may have a problem with the compressor being de stroked. What year Saab?
Re: High suction pressure and high head due to overfeeding expansion valve?
Posted: Sat May 27, 2017 4:06 pm
by Swedal
Thank you for helping! How can I fiddle wth the bulb on a cars expansion valve? I though everything is built into that solid block of the valve? Car is a 2003 Saab 9-5. I would really like to try manipulate the expansion valve to see if it changes.