tdcarter72

I am in the process of replaceing my 23 year old leaking vacuum hoses, at least the ones I can find.

Anyway, I have two hoses that are in the top of my air intake box that I do not know where they go. Here are a couple of pics of the air box and the hoses.

1987 F-150 XLT Lariat 4x4 5.0L

Thanks for any help.

Just call me Sean

iTrader: (1)

That sucks. The vacuum diagram is supposed to be right there on the airbox. My 4.9 doesn't have those.

tdcarter72

None of the 5.0L in the junkyard have them either, but most of them are in 1990 and up model trucks. Maybe someone will have an idea of where they go and what they are for.

ponypoor2

The lines you are asking about are for the heat riser. The plastic red line should go to manifold vac and the rubber hose goes down to the vac motor on your air intake right where it comes through the radiator core support. It's what directs warm air to the intake in cold weather.

tdcarter72

Thanks for the reply, I do have a couple of questions.

Can the plastic red line be replaced with regular vac hoses or do I need to stay with the plastic hose? And when you say manifold vac, you are talking about the vacuum tree on top of the intake?

Does some body have a pic of the vacuum motor? I had my radiator out two weeks ago and do not remember seeing anything like this, but I could have over looked it since I was not looking for it. I will look today if the rain stops long enough for me to get out there.

Thanks again for any help on this. I know running down these vacuum hoses are going to be a real pain in the butt without vacuum diagrams. So far I have installed 3 hoses that were not even there! No wonder its been running rough.

dirtcrew51m

The hose for the heat riser comes off a port on a ported vacuum switch that is open when cold, you could use other hoses in place of the hard hoses, but the plastic hoses actually last longer, if you want to change it, go to Lowes or the Depot and get the clear hose, I think they have 1\4 and 1\8 sizes. Also the clear and hard plastic does not collapse like rubber especially when rubber gets oil soaked and brittle from the heat.

Just call me Sean

iTrader: (1)

They have the plastic lines at the parts store too, in black, but you can use rubber too.

tdcarter72

Just so I understand, the rubber hose will go to my ported vacuum switch, a the red plastic hose will go to my vacuum tree on the intake? If this is the case, I may need to find a vacuum diagram for my truck because my vacuum tree is full on the intake.

Just call me Sean

iTrader: (1)

Ymeski has the same truck as you. Maybe he would be so inclined to take a picture of the vacuum diagram for you?

ymeski56

Let me check my bag of tricks. Going to have to take a Pic & transfer to the computer, ect,ect........................Unless Alldata has something.
Now back to being so reclined!