Lazarus-F150

My blower motor died recently and while in the process of replacing it I noticed that a line coming from what appears to be some sort of diaphragm valve was disintegrating. I have attached a photo with the valve indicated by a red box and the line (with break) is indicated by a yellow arrow. When I move the arm on the valve it opens a gate on the firewall side of the blower. Can anyone tell me the name of the part and what it does?

P.S. its a 1992 4.9L if it is helpful.

Thanks!

87f-150

It controls the fresh air blend door .

matthew13sanderson

yep

Lazarus-F150

So, is there a pressing need to replace the part/line since the line has basically disintegrated?

Thanks!

fordtrucknut

not unless you only use your defroster, if you plan on using the dash vents it will need replaced. normally it is only disintegrated on the visable hose and if you cut back the covering it is normally good, you want to use about the same diameter hose and join it together with some larger snug fitting hose(use rtv).

Just call me Sean

iTrader: (1)

Inside air/outside air, that's the only thing it affects (unless it's leaking). I forget which is default.

FordRoushFan

My father has a 1993 4.9 XLT and that same hose broke on him. When we were messing around with it we noticed that the MAX AC would not work. Everything else worked but not the MAX AC.

Just call me Sean

iTrader: (1)

Max A/C is inside air.

Snaggletooth

So that line breaking will keep the air in the cab from coming on? Could be my problem, it worked before it busted.

FordRoushFan

Good to know. Thank you for the information!!