mikebanx

I have the same prob. My hose looks the same as yours right now, is that how it looks stock or is the black hose the replacement hose you used? I just looked at mine and it looks exactly the same as in your pic.. but right where the black hose stops theres holes in the white one leading into the bundle.
Did you just cut the white one by the bundle and slide the black one right over it? no glue or anything?

USAF93

I just had this same problem. You can view my photos here https://www.f150forum.com/members/us...c-vacuum-line/

dhonnoll

I can tell No difference between Normal A/C and Max A/C. The blower should feel a little bit stronger and sound a lot louder on Max A/C which should be recirculating air. I dont have the problem of it going all the way to defrost or anything or not coming out of the vents but I do have the problem of it never seeming to go to Max. What controls the MAX A/C? Is that also the white vacuum hose on that solinoid lever thing above the blower? I have patched that piece bot not replaced it. Do I need to better patch it or replace it maybe? Does anyone sell them new?

fltdriver

My guess would be that there is a leak in that line attached to the blend door actuator. Without it shutting all of the way the blower motor isn't working as hard to circulate the air because it's getting a flow of air. I'm assuming this is what makes the Max air sound louder and makes it feel like it's blowing harder (because the blower motor increases speed to circulate the air since it's no longer being helped by the natural air flow). Have someone turn the control from regular to max and watch the actuator. Then have them turn it from Floor to defrost and watch the actuator. If it moves equally for both tests then it's the white hose, if the max doesn't move it (as much or at all) it could be the contacts on the selector switch or the line going from the selector to the group connector inside the dash.

As for finding a specific line you probably won't have any luck, you can get a vacuum line almost anywhere that will work though. I believe 4mm ID is what it is, I just replaced all of my engine vac lines with 4mm silicone lines and the originals where roughly the same size, though the white one may be larger.

Twister2014

I have a 1994 ford F150 XLT i replaced that hose with the smallest vacum hose and i still have the same issue i peeled back the wiring harness to the point where it looks brand new and when i hit the gas pedal it still reverts back to the defrost vent
any help would be greatly appreicated i checked the other vacum hoses they are all pulling vacum at the check valve

raski

You are responding to a ten year old post and a last entry six years ago.

Steve83

Read the last TSB in this caption:

(phone app link)