ac quits blowing when going up a hill

[Flame]

Blue, I went by the video in one of the earlier posts so I will try to help best I can. First ofall The canister I got is a Dorman brand part #47076. I also picked up a package of various universal vacuum hose connectors. Under the hood near the oil filler cap is a RED vacuum hose encased in a "wiring" harness. Unplug that and hook your new hose to it. Run it over to the fender and drop it down inside where you can see it with the passenger door is open. Then see that silver dollar size plastic plug in the outside of the cabin and cut a hole in it big enough to get your hose through into the passenger side floorboard. Look for a "tiny" plastic vacuum line going into the firewall. It will be run through a rubber gromment for protection. Cut it loose on this side of the gromment. That little hose and the larger one you ran from under the hood are the 2 that hook to the canister. Use your adapter kit to match whatever size fitting you need to hook up. At this point you are done and it will work!! Don't worry about capping any hose off you cut from. They will no longer have a capability to leak.Only thing left to do is tuck away the canister and you will probably need to add a extention to the littlest hose to make it reach where you want it. I did not even screw my canister down. I tucked it in on the far left and up of the passenger side compartment and it stays just fine. Don't really know what size hose I ran from under the hood because I had about 5 different sizes in my shop to "grab" from. Whatever size will hook up under the hood just get about 6 foot of it to make it easier to route. Let me know if you need anything else. I got my part from O'Rileys. Let me know if you do it. I actually do think it makes my AC blow harder now!!

[Blue~Go]

That sounds a lot easier than I was imagining. Thanks!

[Flame]

It is very easy. Just be careful not to run the hose under the hood where it will get pinched when closing the hood. Also I made a "hook" out of clothes hanger type wire to reach into fender to grab the hose. Easily done by yourself but could even be a little easier if you had a friend help when pushing it through the rubber plug. Good luck!!

[Flame]

Well, just got back from a Memorial weekend trip 500miles round trip up and down a lot of hills. The new vacuum canister worked GREAT!! Just thought I would pass on a $20 fix does work!!

[Blue~Go]

Glad to hear it.

Amongst the many positive reviews on Amazon (specifically about our chassis even), was one saying it did not have enough volume for an E-450. They didn't mention which engine tho. So then I looked around for maybe a better one but got bogged down in trying to figure out what might BE a better one.

So then I decided to just order the same one you did because the hard part will be getting the lines routed, fittings correct, etc -- and if this one isn't big enough it shouldn't be that hard to swap just the canister (and add a check valve if not built in to another one).

To that end one should be arriving for me today.

[Flame]

Blue, let me know how it goes!! For all the times (and money) you have saved me and helped me I am tickled to be of some assistance to you for a change!! Good luck.

[markatherton]

There is another fix which I have done before. You can cut a small access window in the inner fender behind front passenger wheel, which will allow you to access the vacuum valve. You will probably find the vacuum lines have deteriorated from the ethanol in the gasoline. When you are finished you can make a small sheet metal plate to screw over the opening allowing you to gain access anytime you want. I will try to attach a file outlining the procedure.You can probably find the entire repair procedure on the internet.

[markatherton]

This is the write up that goes along with these pictures

[caconcourse]

I just completed this fix also because rats ate my vacuum hose under the hood. Here are the parts I purchased, on Amazon:

New hose, just long enough for replacing the original:
https://www.amazon.com/gp/product/B0006 ... UTF8&psc=1

New Dorman 47076 reservoir, tucked up inside passenger compartment:
https://www.amazon.com/gp/product/B000C ... UTF8&psc=1

Rubber fittings to attach new hose to cannister, only one needed, but handy assortment:
https://www.amazon.com/gp/product/B002H ... UTF8&psc=1

I left the original red vacuum hose form the engine in place and attached the new hose directly to it at the same joint as the original black hose, which is near the top of the air conditioner recharge tubes behind the battery. You can see where the original black vacuum hose comes through the bulkhead by the passenger foot area. Just grab the old hose (1/8" diameter black hose) and yank it, and the rubber bulkhead grommet will pull out of the bulkhead. You can reuse the grommet for your new hose for a sealed bulkhead fitting. I passed a piece of baling wire up from the passenger compartment through the bulkhead hole and straight up the engine side of the bulkhead to where you can reach it behind the battery. I attached the new vacuum hose to the baling wire (just stuck the wire inside the end of the new hose) and pulled it down into the passenger compartment, so the new hose travels the same route as the original, but bypasses the broken check valve/tank behind the bulkhead. Then attach the new hose to the new tank with a rubber fitting, and attach the old (gray) vacuum hose in the passenger compartment to the other fitting on the tank (which has an integrated check valve). The original black hose connected to the gray hose with a fitting you can move over to the new tank.

The whole job took about 10 minutes with the new parts, and all the HVAC functions worked perfectly. The parts cost less than $30.

Note that without vacuum, the HVAC will default to the defrost mode, and all air will come out the defrost vent (A/C, Vent, Heater). If the reservoir is compromised, but vacuum is available from the engine, the vents may still work, but when going up a hill, the engine vacuum drops, and the vents will switch to defrost since there is no reservoir for maintaining the vacuum while the engine doesn't have any. Consequently, you need the tank to hold vacuum during outages, and the check valve keeps the air from entering the tank when there is no suction. The Dorman 47076 has a built-in check valve, so you can replace two original (expensive) Ford parts with a single item that does both functions.

[Hea!]

While driving my Chinook home last week it had the symptoms exactly as described.
No panic on my part, I had read these threads in advance.
Now I need to decide if it's worse to fabricobble the fender patch together or do the bypass.
Here's an excellent video of what looks to be an afternoon of phutzing around...
https://www.youtube.com/watch?v=ddcZnubJJgc