9

I didn't see this question asked after searching through the tag but I was curious is it ok or would it even work on a Silverado if you remove the fuse for the fuel pump when it is running and let the engine lines run dry before changing the fuel filter? I'm trying to prevent excess of fuel loss after unscrewing the fuel filter since it is at the lowest point of the fuel line. I do not want to run the tank dry because I've always been taught that it's bad on your fuel pump to let your gas get below a certain depth.

5
  • 1
    I've been told that too. It was in the '80's though. My first shop manager would beat me to death with it. he said the the rubber diaphragm in the pump would get dry and it would degrade the life of the diaphragm leading to a failure sooner, I've never validated the truthiness of it. Apr 14 '16 at 20:12
  • 1
    Ya i was actually thinking of making that my second question. Apr 14 '16 at 22:31
  • 1
    I think there might be quite a bit of urban legend associated with various belief systems. It would be interesting to see if someone could come up with facts related to degradation of the diaphragm or not. I don't think what I've been taught is necessarily FACT. Apr 14 '16 at 22:40
  • I made it into a question. Curious to know the answers. Apr 14 '16 at 22:41
  • This should be good. Hopefully someone has the answer. Apr 14 '16 at 22:43
9

While disconnecting the fuel pump relay and running the engine will work, there are other alternatives.

If you can access the Schräder valve, depress it to release the pressurized fuel before disconnecting the fuel lines. This will have the effect of reducing fuel line pressure. It helps to have the vehicle cool down and not running for a few hours.

I don't have a Silverado, but my BMW has a similar arrangement with the fuel filter strapped onto the driver-side underbelly. What I can say is that the amount of fuel that pours out upon disconnecting the fuel line is not that much.

5
  • My E28 BMW has the fuel filter on the low pressure side- between the in-tank transfer pump and the fuel pump, so what does come out is not at high pressure. Apr 14 '16 at 20:43
  • @SpehroPefhany I'm talking about an E39 M5. Totally different beast. Here's a video
    – Zaid
    Apr 14 '16 at 20:45
  • That's an interesting design choice. I wonder why they did that. I would have thought that tey would want the filter on the high pressure side so fuel is more likely to get passed through the filter. I feel like I'm mmissing something about this though..
    – cdunn
    Apr 14 '16 at 20:46
  • Yes, very different. The Schrader valve is a nice feature. Thanks. Apr 14 '16 at 20:48
  • @cdunn the "sock" is still going to act as a coarse filter pre-fuel pump. The filter I'm talking about sits between the fuel pump and the fuel injectors
    – Zaid
    Apr 14 '16 at 20:54
6

You are correct in how to do this. I was just watching an episode of "Tech Garage" and they were talking about this very topic. Their suggested methodology was to pull the fuel pump fuse, and run the engine till it stopped on it's own. You can now change out the fuel filter. You will still get some fuel out of the line, but nothing like having 30-60 psi of fuel spit at you.

This site is temporarily in read only mode and not accepting new answers.

Not the answer you're looking for? Browse other questions tagged .