F250 - vacuum pump

Reply Subscribe

Thread Tools

Search this Thread

Apr 15, 2016 | 12:59 AM

Amaford

Thread Starter

New User

Joined: Apr 2016

Posts: 19

Likes: 0

F250 - vacuum pump

Hello again

I have a 2005 F250 , 4.2 tdi diesel. I just bought the truck recently and still getting to know it.

I noticed recently that when I turn on the key, the vacuum pump starts running and does not go off. It seems to run continuously and will only shut off if I block the white outlet pipe with my finger. Is this normal or is the pump stuffed.

thanks in advance.

Apr 15, 2016 | 01:00 AM

Thor'sHammer

Laughing Gas

Joined: Sep 2013

Posts: 1,031

Likes: 13

I believe the white pipe is the intake?

You likely have a vacuum leak. Is the truck 4wd?

Apr 15, 2016 | 01:02 AM

Amaford

Thread Starter

New User

Joined: Apr 2016

Posts: 19

Likes: 0

Hi

Yes the truck is 4x4 and does not engage until I manually lock the hubs in the front.

Apr 15, 2016 | 01:11 AM

Thor'sHammer

Laughing Gas

Joined: Sep 2013

Posts: 1,031

Likes: 13

Quote:

Originally Posted by Amaford

Hi

Yes the truck is 4x4 and does not engage until I manually lock the hubs in the front.

Get a vacuum tester and start testing lines leading to hubs. If you check at the hub and it leaks, the hub seals are bad. I have found that the lines deteriorate quickly and need replacement after a couple of years.

Also, check behind your glove box at the vacuum line connection on the HVAC unit. It can get unplugged from there sometimes. Definitely unplug the pump though if you are going to use the truck while troubleshooting. The pump is expensive and will burn up if constantly run.

Apr 15, 2016 | 01:15 AM

Amaford

Thread Starter

New User

Joined: Apr 2016

Posts: 19

Likes: 0

what is the white outlet pipe that I block with my finger , for?

Apr 17, 2016 | 09:08 PM

Thor'sHammer

Laughing Gas

Joined: Sep 2013

Posts: 1,031

Likes: 13

The white pipe is the exhaust from the pump. I actually just replaced mine this weekend as mine would run at startup, lose vacuum and never restart to charge the system with vacuum, unless the key was cycled or the unit was unplugged and plugged back in. Replaced with a $50 dorman unit and all is well again after testing for leaks.