Hi guys, I want to change the fuel sending unit with a friend. My gas gauge is not working and I would like to take a long trip and not get stuck somewhere in PA with no gas stations around. I am not mechanically inclined but I am on a high since cleaning my MAF by myself. I am a troubleshooter, and I take my time when doing something, but I can't figure out how to relieve the fuel system pressure.

Also, I was hoping to know in the first diagram of the fuel tank removal DIY; https://blazerforum.com/forum/tech-articles-diy-29/gmt360-fuel-tank-removal-40691/, how is that top end where #1 is accessible? isn't the truck's sheet metal in the way of reaching that?

any suggestions would be greatly appreciated.

 

Try my method to relieve the pressure, put your face in front of the line then yank until it comes off, when it starts spraying in your eyes, quickly roll out from under your car and wipe your face off, then toss a bucket under wherever it's spewing gas....or you can remove the fuel sending fuse in the engine fuse block and run the engine till it stalls...your choice

 

Just so you know, that procedure is for the newer 2002+ Trailblazer, Envoy, Bravada, etc trucks and does not depict the s-series vehicles.

As far as your question goes, you have to drop the tank down a bit to be able to get your arm up there.

 

...... that sucks

 

I pulled the fuel sending fuse on my 2001 to relieve the pressure for a fuel filter replacement? isn't that the same pressure thats built up just another spot along the line? i could be misunderstanding something though haha

 

You can pull the fuse for the fuel pump or the relay and try to start the motor. That will relieve some of the pressure, but with the stock CPI and SCFI spiders using poppet nozzles, there will still be 40-50psi in the lines.

My statement wasn't concerning the release of fuel pressure, but rather, the removal of the tank and disconnection of the lines, etc on top.

 

Alright thanks I just wanted to clarify my own information haha

 

is 40-50 PSI still enough pressure to spray like hell or is it manageable?

BTW thank you everyone for the input..

 

It'll still spray, but its not like the pressure will still be there after a second or two. It will bleed off quickly. Just wrap a rag around the test port and bleed the rest of the pressure off with a screw driver pushing on the schrader valve. Then all you will be dealing with at the tank is the fuel in the line.

 

I have given the tank drop careful consideration. I have a friend that has experience working with blazers and he is a mechanic but he is young like me and can work on the truck in my garage (charge me less for it).
We will both do the job, and every significant step of the way I will take a photo of for the site. It is the least I could do after you guys helped me so much.