My neighbor who is a member of FTE (Y2KW57) is currently on a road trip and is having some issues. Here is what he sent me ......

Im in Wyoming with a vacuum pump problem. Its running constantly. It never shuts off. This is a problem that can lead to battery drain, pump wearing out, and eventually no heater... Which I desperately need in the 23 degree climate here. I don't have Esof. I have wiggled all the lines to the pump as well as behind the glove box for the hvac. I didnt see this one coming. Any ideas? Can you ask on FTE for me? I have 1700 miles to go before getting home. thanks!

So I wanted to get any info that any FTE member may have so I can pass it along to him. Again he is currently in Wyoming with the issue.

He has a 2000 F550 with the 7.3 liter diesel.

Let me know what other information you need to help diagnose and I will ask him.

Tim M

 

Temporary fix: unplug the vacuum hoses and put some kind of cap to close off the outlets to simulate a closed system. This will disable the HVAC so be sure to set it to a good setting first, preferably DEFROST as a safety measure.

If he has time to dig, I would trace the vacuum lines. I know he said he did, but do it again. If that is a no go, try the little white box on the fender wall. I believe that is some sort of vacuum solenoid that triggers the pump to engage.

 

Trey, I sent him what you suggested.

I also sent him the following info which is in line with Trey to double check his lines and pump. I found this on another thread.

ok the vac pump is a pretty simple device, i would suggest you unplug the line leaving the pump that goes to the vac reservoir. hold your finger over the end to plug it. feel if its pulling a vacuum or not. if it is and the pump stops check for a vac leak. if it is pulling vacuum and the pump keeps running replace the pump. just make sure you dont have a vac leak which i doubt because the pumps dont put out much for vac. most small leaks i have found the pump cant keep up with and run the a/c 4wd controls.
the pump only has 2-wires, 1-hot when enigne is running, and 1-ground wire. the pump has an internal pressure switch to cut the motor off. it sounds like the switch is bad inside the pump causing a continuous run.

Last I found this bulletin for a vacuum pump issue.

Vacuum Pump Inoperative Or Runs Constantly - Climate Control Defaults To Defrost Mode

<table border="0"><tbody><tr><td width="230">FORD:
</td><td>1999-2006 F-Super Duty
2000-2005 Excursion
1999-2006 F-650, F-750</td></tr></tbody></table>

ISSUE:

Some 1999-2006 F-Super Duty and 2000-2005 Excursion vehicles built before 6/27/2005 and 1999-2006 F650/750 vehicles, all vehicles equipped with the 7.3L or 6.0L diesel engine, may exhibit a vacuum pump that is inoperative or running continuously. If the pump is inoperative, the climate control system will default to defrost mode and the 4x4 system may also be affected.
ACTION:

Install a new vacuum pump. Before replacing the pump, check for and repair any pinched or leaking vacuum line(s). Refer to Workshop Manual Section 412-00 for additional information.

<table border="1" cellpadding="3" cellspacing="0"><tbody><tr><th align="center">PART NUMBER</th><th align="center">PART NAME</th></tr><tr><td class="yiv761252699NOBOTTOMBORDER" align="left">6C3Z-2A451-BA</td><td class="yiv761252699NOBOTTOMBORDER" align="left">Vacuum Pump</td></tr></tbody></table>

WARRANTY STATUS:

Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
<table border="1" cellpadding="3" cellspacing="0"><tbody><tr><th align="center">OPERATION</th><th align="center">DESCRIPTION</th><th align="center">TIME</th></tr><tr><td class="yiv761252699NOBOTTOMBORDER" align="left">051704A</td><td class="yiv761252699NOBOTTOMBORDER" align="left">1999-2006 F-Super Duty: Replace Vacuum Pump (Includes Time To Check For Leaks) (Do Not Use With 2451A)</td><td class="yiv761252699NOBOTTOMBORDER" align="left">0.3 Hr.</td></tr><tr><td class="yiv761252699NOBORDER" align="left">051704A</td><td class="yiv761252699NOBORDER" align="left">2000-2005 Excursion: Replace Vacuum Pump (Includes Time To Check For Leaks) (Do Not Use With 2451A)</td><td class="yiv761252699NOBORDER" align="left">0.3 Hr.</td></tr><tr><td class="yiv761252699NOBORDER" align="left">051704A</td><td class="yiv761252699NOBORDER" align="left">1999-2006 F650/750: Replace Vacuum Pump (Includes Time To Check For Leaks) (Do Not Use With 2451A)</td><td class="yiv761252699NOBORDER" align="left">0.5 Hr.</td></tr></tbody></table>
DEALER CODING

<table border="1" cellpadding="3" cellspacing="0"><tbody><tr><th align="center">BASIC PART NO.</th><th align="center">CONDITION CODE</th></tr><tr><td class="yiv761252699NOBOTTOMBORDER" align="center">2A451</td><td class="yiv761252699NOBOTTOMBORDER" align="center">42</td></tr></tbody></table>

These are for anyone wanting additional information if they run across a similar issue.

-------- I sent this information to Y2KW57 but I have not heard back from him so I hope he was able to use this information. I tried calling him but no answer and his voice mailbox was full. ----------

I will update if I get any information from him on his trip and if anyone else has advice please let me know and I will send it on his way.

Thanks, Tim M

 

I missed Y2KW57's call but he left a message and Trey it seems the workaround mentioned is a good alternative. His temp is set on a manageable temperature and he did something to stop his pump from constantly running. He feels confident that he will not have any issues for the remaining journey home.

When he gets back he will most likely address the Bulletin that was posted.

Thanks, again.
Tim M

 

Awesome! Glad he was able to resolve it until he gets home.