Losing Vaccume at high speed

[AA7KN]

I have a 98 Xlt auto trans. I love the old Girl, never lets me down. I do a lot of highway speed traveling for my job and I have noticed that when I'm cursing at speeds over 6o or 70, that from time to time the A/C vents stop blowing out of the A/C Vents, and it switches to the Defrost vents. If I do nothing, in a couple minutes it will switch back, but if I slow down they will switch back right away. has anyone had this problem ? everything is cold and working good except the vents it uses changes. I'm thinking it is losing vacuum which it uses to actuate which door is opened to direct the air flow. so any thought on this would be a great help, and thanks in advance for your input.

 

[nameskreen]

I had the same problem a couple of months ago with my 98. There was a broken vacuum line coming from the canister behind the passenger inner fender. I went to AutoZone and bought a pack of assorted vacuum lines and fittings. Not too difficult.

 

[AA7KN]

I had the same problem a couple of months ago with my 98. There was a broken vacuum line coming from the canister behind the passenger inner fender. I went to AutoZone and bought a pack of assorted vacuum lines and fittings. Not too difficult.

Thank you very much. I will check that.

 

[blakshukvw]

The vacuum canister is probably bad. It’s a ball shaped pot under the passenger side headlight. Access is easiest from under the front bumper after removing the inner fender liner front fastening screws only. Don’t remove the whole liner just the 2 or 3 screws you’ll see when you look up from behind the fog light. The ball is screwed to the fender liner to so you’ll have to remove those screws as well. Easy job. Junkyard is your best bet to find another pot.

 

[donalds]

motorcraft F67Z19A566BA