Vacuum Pump Issue?
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Trailering
Joined: May 2023
Posts: 21
Likes: 9
From: Center of Oklahoma
Vacuum Pump Issue?
I have search the Forums, but cannot find anyone having my issue. The A/C blows ice cold every day on first start up and also when traveling at speed on highway. But once truck has warmed up and running at city traffic speeds, the blowing air goes pure hot! Not talking about just warm, I mean hot air like heater is on. I first installed a manual shut off valve in the heater hose, this had no effect. Had the A/C system purged, checked and recharged. Also had the A/C clutch gap checked.
Why does the A/C cooling return to normal every time I am back at highway speeds? Could the vacuum pump be failing after is gets hot? Does anyone know if the "blend door" has to see full vacuum to keep the heater core air flow shut off?
Why does the A/C cooling return to normal every time I am back at highway speeds? Could the vacuum pump be failing after is gets hot? Does anyone know if the "blend door" has to see full vacuum to keep the heater core air flow shut off?
Laughing Gas
Joined: Nov 2020
Posts: 988
Likes: 364
From: Republic of Texas
17 years of trucks, countless engine and transmission combinations.
No maintenance history
No real modification or change history
No indication of proper engine monitoring gauges
No location or environment indication, maybe somewhere in Oklahoma, however those tags are often not updated.
Details.....
No maintenance history
No real modification or change history
No indication of proper engine monitoring gauges
No location or environment indication, maybe somewhere in Oklahoma, however those tags are often not updated.
Details.....
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Patrick53
Explorer, Sport Trac, Mountaineer & Aviator
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Jan 27, 2019 10:40 AM
dpbrowne
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Feb 23, 2005 02:11 PM
