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what could this be?

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Old Nov 22, 2008 | 05:13 PM
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what could this be?

I just got in working on my new highboy the brakes were way out of adjustment so I couldn't get a peddle now I can finally stop. they are 4 wheel drums. in my inspection of the truck I noticed a round can with 2 hoses coming out of it on the inner fender were the jack should go. does anybody know what this is? looks like one of the hoses goes through the middle of the fire wall.
 
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Old Nov 22, 2008 | 06:45 PM
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It's a vacuum reservoir. Do you have air conditioning or cruise control?
 
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Old Nov 22, 2008 | 08:33 PM
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It's a vacuum reservoir; used to maintain vacuum to the AC\heater controls during periods of low vacuum, such as WOT.
 
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Old Nov 22, 2008 | 09:33 PM
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yeah that would be it. the truck does have AC. is this needed? without it will the ac still work properly.
 
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Old Nov 22, 2008 | 09:44 PM
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If you remove it, then your AC controls can let go of the plenum doors when you're giving the engine a lot of gas. There really is no reason to remove it, it's tucked up under there out of the way and doesn't cause problems unless it rusts through.
 
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Old Nov 22, 2008 | 09:58 PM
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yeah your right. I will leave it. thanks
 
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Old Nov 22, 2008 | 10:19 PM
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Originally Posted by fmc400
If you remove it, then your AC controls can let go of the plenum doors when you're giving the engine a lot of gas. There really is no reason to remove it, it's tucked up under there out of the way and doesn't cause problems unless it rusts through.

would it have any affect when it is selected on the heater?

my vents if they're on AC/HEAT/VENT and it is blowing out of the dash vents, if I give the engine a lot of gas they go up to defrost until I let the gas down and then after 30seconds/minute it goes back to coming out of my dash vents
 
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Old Nov 22, 2008 | 10:55 PM
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We call those the "can of peaches" can of pears, can o ham, can o' whatever, a dozen eggs, all depending on the size and shape of the reservoir.
 
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Old Nov 22, 2008 | 11:09 PM
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Originally Posted by brentleedragon
would it have any affect when it is selected on the heater?

my vents if they're on AC/HEAT/VENT and it is blowing out of the dash vents, if I give the engine a lot of gas they go up to defrost until I let the gas down and then after 30seconds/minute it goes back to coming out of my dash vents
The entire AC\heat direction system is controlled by vacuum, so the reservoir not functioning problem can cause the problems you are describing. The reservoir could be rusted out, or the check valve nearby could have failed open.
 
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Old Nov 22, 2008 | 11:14 PM
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alright is there a part number I can look up for it? or at least an actual name other than can of tomatoes :-)
 
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Old Nov 22, 2008 | 11:39 PM
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It's a vacuum reservoir, or a vacuum canister. Either will get you what you need. Parts houses will not have a ford part number to cross reference to get you a replacement if you need one. I would hit the junkyard to find one similar to replace the one you need. If yours has a small hole in it, plug it with JB weld. Borrow a vacuum pump plug other ports and draw 15" of vacuum, see how long it holds it. It should retain it for a while.
 
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Old Nov 23, 2008 | 12:37 AM
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Could also be the check valve or the vacuum routing in between, all of which are easily obtainable at a parts store. New vacuum canisters are more of a bulb shape than a coffee can, from what I've seen.
 
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