2008 Explorer XLT - A/C air swaps to defrost when under strain
Asked by BugPilot Oct 21, 2009 at 09:23 PM about the 2008 Ford Explorer XLT
Question type: Maintenance & Repair
My '08 Explorer has 60k miles on it. When driving under normal conditions with
the A/C on, the air blows normally from the console vents. When there are high
RPMs (such as climbing a hill or prolonged accelerating)the air swaps from the
front vents to the defrost vents. One repair shop claimed they repaired it
when they replaced a leaking vacuum hose, but it still occurs (though not as
often). There is no Haynes Repair Manual for the '08 model. I also cannot find
evidence the late model Explorers have a vacuum pump.
Any ideas on what I should look for? I can't find a schematic for the engine
(not in the owner's manual) so I'm pretty much at a loss.
6 Answers
I am assuming this is a 4.0 engine. What the manufacturer made to help elliviate this problem is a vacuum tank to hold vacuum under load conditons. Check to make sure all OTHER vaccum lines are conected properly and that they are not damaged going to this vacuum tank and that the vacuum tank did not get damaged by some previous "other" servicing. Good Luck
There should also be a one way valve on the vacuum line to the system, sometimes these stuff up and when under load, the vacuum drops and thus drops the vacuum in the aircon system too
John has a point - I do not think an 08 would be blocked but perhaps the previous repair shop removed it when it broke and did not reinstall one just 'teed' it all together ... I like this thought thanks John
I had a shop pull the reservoir off and test it. It held pressure without any leaks. An idea the shop had (and an expensive one) would be to pull the dash off and inspect for the problem that way. Any suggestions?
I replaced the check valve on the firewall. ($9,online). This solved the issue of AC air moving to defrost during heavy acceleration/towing on hills.
I have a 2006 ford explorer xlt the ac works blow coldair but when you accelater it blows hotair