Vacuum pump not running
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Vacuum pump not running
I have a 2004 F-350 diesel. My vent selector is always on defrost so I suspected a broken hose but traced all out and all seem to be fine. I disconnected the line coming from the pump to the tank and no vacuum. The pump dosen't seem to be running but it's hard to tell with the engine noise and vibration. What tells the pump to run and how can I bench check it?
Hotshot
Joined: Aug 2006
Posts: 17,398
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From: Whittier, CA
I have a 2004 F-350 diesel. My vent selector is always on defrost so I suspected a broken hose but traced all out and all seem to be fine. I disconnected the line coming from the pump to the tank and no vacuum. The pump dosen't seem to be running but it's hard to tell with the engine noise and vibration. What tells the pump to run and how can I bench check it?
If the pump isn't running, then check for 12VDC at the connector. You might just have a bad fuse.
If you can't hear the pump over the engine, just turn the ignition ON but don't start the engine. The pump should run whenever the key is in the RUN position.
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I pulled the electrical connection off and tested the voltage and it is 12.1 volts with the engine not running but the key on. The pump is not running at all. I guess that means it is bad. Now I know why my front wheel hubs didn't lock in in Auto position. 
Lead Driver
Joined: Sep 2007
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From: Scio, OR
Once you get your new pump installed, make sure that it is not running too much. A vacuum leak can cause the pump to run all the time and may cause it to burn out. When you turn the key to run (you don't have to actually start the engine) the pump should run until for a minute or so, until it's pumped down the right amount of vacuum, then it should shut off and stay off. If never shuts off, or starts again in a few minutes or so, you probably have a vacuum leak that you need to trace down and repair.
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Thanks guys - I just ordered a new one from accuratediesel.com. It was $106.99 plus $11.33 for UPS. I'll pay attention to how the new one runs when I install it. I used to hear the pump running while I waited for the glow plugs to cycle but I thought it was the fuel pump. It probably was both now that I think of it. Speaking of the fuel pump - is that a stupid place to install the filter so you get a fuel bath everytime you change it? Ever hear of a retrofit that corrects this?
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Received the new one yesterday and installed it today. The pump ran for a short while and cycled off. All the vents now work as they should. I guess the pump just burned out. Thanks for the help.
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Hotshot
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Great news! Now, stick around, and don't be a stranger. There is much to learn here, grasshopper!
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Crank but no start
Good evening guys, so I’ve replaced my alternator on my 01 ex 7.3. Previous owner said he didn’t have an issue with the charging system except having to change 3 alternators in the past 4 years, lol. After some research I figured it was the alternator so I upgraded to the 200amp by heigermeister. Everything is charging fine and voltage is great. After about an hour of test driving I noticed a shutter around 35-45 mph when accelerating. I drove it back home and used my other ford to run the errands as needed. As I test drove the truck again this evening, I noticed the same shutter when accelerating and about 2 mins down the road a loss of power until it came to a complete stop. It cranked but no start. Had to get towed back home. Anyone have any ideas? I was reading some injectors having to work hard when they don’t have the correct voltage. Can someone help me diagnose this??? I also noticed that my vacuum pump isn’t buzzing anymore.
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