Any ideas where they vacuum leak or what might be the issue?

If I step on the gas the ac will go from blowing from the dash vents to the defrost vent and then if I let off the gas alittle it will blow back through the dash vents. Makes for a long hot ride.

 

Was anybody playing around under the hood lately ? Take a look at the vacuum hose that goes to the hot water valve. It'll be up near the passenger side firewall in the engine bay.


-Mike

 

There is also a vacuum hose that runs under the battery. Corrosion from the battery has been known to eat into the vacuum line.

 

digital or dials? If digital there is O-rings inside that go bad. There is a post here on how to replace them, easy job.

 

I found this hose. It was completely waisted. I replaced it but made now difference. Now I only have blowing through the top defrost vent and the lower vents under the dash.

I found no other vacuum leaks under the hood. Am I goinh to have to take the dash apart to find the other vacuum items?

It is starting to get hot here in Texas and I need to fix this ASAP.

 

Did you follow it in both direction to look for other points of damage? Once the vacuum line is penetrated by the corrosion, the corrosion can then run down the inside of the vacuum line and accumulate at a low spot until it eats through the line at that low spot.

 

I followed the house all the way to the check valve.. I didn't go any further then that. I also follow the vacuum lines I saw coming through the fire wall.

I didn't see any other bad house.

 

read my previous post...

 

The dash vacuum manifold is located at the forward end of the center console below the dash. It's where electrical signals from the climate control are translated into mechanical vacuum controls. It's possible this thing has burned up. When I changed mine out I found it was pretty brown from the electrical heat that's generated there. So my guess is they weren't built to last forever. You have to pull the center console out to gain access to the unit. The part number was 2L1Z-19D611-AA and I think it was about $75.


-Mike

 

It is digital. Where are the O-rings?

 

I have looked at this item. Does this regulate the heat only? What does this valve do?

 

The O-rings are inside the control unit,
Read post # 11 This is the one I used to repair mine (sorry used to be pics). there is some good pics here, Or complete a google list... ford eatc o rings
It is easier than it looks, the pics and steps sound worse than they are. Just be sure to get the correct o-rings, I got mine from a hydraulic hose builder.

 

Jason that is the hot water valve that regulates hot water to the heater core for the climate control. It commonly gets knocked off when people change the sparkplugs or work in that area. Just check that the little vacuum line is correctly attached and not cracked or broken anywhere. Also check the vacuum line that runs under the batter tray that alloro was talking about and the operation of the check valve in that line. If the check valve is bad you will get the loss of vacuum under acceleration as well. I switched to an Optima battery a long time ago to avoid the corrosive battery issues. If all the lines check out the remaining culprit is usually the vacuum control solenoid, that I posted above. The O-rings that others have mentioned are inside that if you want to try your luck rebuilding it with the correct silicone O-rings.


-Mike

 

OK. I replaced the solenoid and still no change. The air is still blowing out the defrost vents and the floor.. I have checked the vacuum lines that were bad. Still nothing.. What else could it be.

It started out blowing out the bash vents but when I stepped on the gas it would stop. Now it is JUST the defrost vents and the floor.

I really don't want to take it to the dealer to have this looked at..

 

I don't blame you, it could take them hours to find the vacuum leak. At this point you've check all of the obvious things, so it's time to roll up your sleeves and dig into it. I suggest getting a handheld vacuum pump and just start testing everything for leaks.