Garywallace

This is my first post since buying my 1996 f150 302 5 speed regular cab. I have several issues that may be caused by the same problem first the air is very cold but is hardly coming through the panel vents. The blower sounds like its really blowing hard. Second part is the white vacuum line under the hood by the blower on the passenger side close to the hood hinge was broken so I replaced it .(what is the part called that line goes to)third part. When I change from first to second gear there seems to be a burst of air coming from the vent I haven't been able to tell where the burst of air is coming from . I am not a machanic by no means but would like to attempt to fix this myself any help would be great

sylver91

Welcome to the Forum

Sounds like you got more than one vacuum leak. When you shift from 1st to 2nd, you put a load on the engine to get up to speed at you hit the gas. When you hit the gas you open the throttle up and loose vacuum which will close the vent behind the dash. Once you get up to speed and you give it less throttle, vacuum returns and opens the vents again.

That white vacuum line you fixed is for the outside blend door.

Here is a diagram of what vacuum lines do what and where you should start looking. Spray small amounts of carb cleaner on your vacuum lines, intake and throttle body gaskets while your engine is running. If the rpms drop, you have an idea where your leak is.

Check the lines to your vacuum tank as well.

Garywallace

Thanks, we will start back in the morning. Is a vacuum leak serious?

sylver91

Its not that serious, but vacuum is what controls some of the systems for the truck like the EGR, AIR diverter valves and differential pressure feedback sensor which can affect performance and economy.

oakey

Check if some replaced the blower . On mine someone did and the wires were crossed even though they were the same colors .

Garywallace

When I spray the carb cleaner on the lines what will I be lookings for? Air bubbles?

mr7confused

The air leak in the line should suck in the carb cleaner and it will get into the engine, in which you will hear the engine pick up or run a little differently for a second or two.

Garywallace

I did find two leaks and fixed them thanks to you!! But my ac is still not blowing hard. The blower switch goes for low to high but it just doesnt seem to be blowing out very much air. Not really sure what to check. I did look under the dash to make sure there was not anything blocking the air flow and there was'nt. Everything seem to be working ok when i select Defrost,vent,ac etc. just not getting much air out of the panel or floor.

mr7confused

It doesn't smell or anything, does it? Suggesting a rat or something is plugging up the works?
Or maybe your blower is missing fans or something. Might be worth a looksy into the blower motor and fins of the blower.

Garywallace

No smell but I'm going back out when it cools down a little today . I'll post back thanks