8 replies to this topic

[tra68]

Its time to replace the fuel pump in my '99 SM.  Between the cage and the diligence of my builder's looming of the wires under the dash, I can't seem to get to the fuel pump relay.

 

Can I de-pressurize the fuel system by disconnecting the electrical connector at the top of the fuel pump assembly (as opposed to disconnecting the fuel pressure relay as recommended by the shop manual)?

 

Thank you in advance for any help or suggestions.

[trimless]

Disconnecting the electrical connector will do nothing to relieve fuel pressure. With that being said, put a shop towel under the connectors and separate them. Easy peazy, the fuel does not shoot out like a  faucet. Only a small amount of fuel spilled.  At least thats how I remember it the last time I replaced the fuel pump in my 99. Disclamer: I'm certain that the shop manual has a procedure for relieving the fuel pressure, but I do not think it is necessary so just passing on my experience.

 

I also light my bar-b-que pit with gasoline, unleaded 87 octane 

[HoneyBadger - BrianW]

I also agree that its not necessary, our fuel systems 1) dont have that much pressure and 2) tend to leak pressure back down fairly quickly. If you want, you can hook up your fuel sample hose and that should relieve any pressure in the system before you unhook the fuel lines to the pump.

[ChrisA]

The "Official" procedure is to pull the fuel pump relay, start the engine and let it run until it dies. I agree with the above, pressure will leak down fairly quickly. Put the disconnect tool on the line and wrap a shop rag around it just incase it is holding a little pressure and to catch the bit of gas that will dribble out. Now, if you are also changing the fuel filter out at this time, I would recommend having the tank as close to empty as possible. Gravity will the push fuel out and make a simple job rather trouble-some. (Unless you have them pump hanger out when you change the filter)

[fotostars]

I also agree that its not necessary, our fuel systems 1) dont have that much pressure and 2) tend to leak pressure back down fairly quickly. If you want, you can hook up your fuel sample hose and that should relieve any pressure in the system before you unhook the fuel lines to the pump.

 

+1, hook-up your fuel sample hose and put a rag at the end... You'll see it's really not much if any...

[Jeff Wasilko]

and also remove the gas cap to relieve pressure in the tank.

[Keith Andrews]

When you reconnect the fuel line, make sure to give it a strong tug to make sure it is really snapped together.  I thought I had the lines connected recently only to have them pull apart when they were pulled on.  They seemed to snap together the first time but they pulled apart with a strong tug.  Fortunately it was discovered before we had covered everything up. 

[Bruce Wilson]

and also remove the gas cap to relieve pressure in the tank.

And leave it off until everything is reconnected.  An increase in temperature expands everything and pushes fuel out the unconnected parts -- at the most inopportune times!

[tra68]

Thanks to everyone for the very helpful and timely suggestions, I appreciate the help.