Bleed air from fuel system?
 

I’m getting very close to first start up. Just waiting on a driveshaft and some air intake tubing. I thought I’d pour some gas in and power up my fuel pump to check for leaks. I was wondering if I need to bleed air out of the new fuel system?
08 5.3

Re: Bleed air from fuel system?
 

I never have

Re: Bleed air from fuel system?
 

Okay. That’s good to know. I also still need to pick up a cheap weed sprayer to do a pre oil when the time comes.

Re: Bleed air from fuel system?
 

On a returnless system that is completely dry, just turning on the key may not get fuel all the way to the rail, depending on where your regulator is. You need to crank the engine so that the injectors open up to let the trapped air out.

Re: Bleed air from fuel system?
 

As said above just start it and it may sputter a bit or even die a couple of times until the air is purged. One of the coolest things about first starts on LS engines is if you have everything hooked up correctly they fire and run almost instantly.
Not to say you can't but I've done a number of LS swaps. New rebuilt and used. I've never pre-lubed mine. I just pull the main 12 volt for the ECM. Crank the engine until I see oil pressure on the gauge and that's it. It doesn't take long. If you have fresh oil and oil filter make sure you fill the filter before spinning it on.
Just my .02. Good luck with your first start.

Re: Bleed air from fuel system?
 

Ya the pre oil is probably overkill but easy enough to do for peace of mind. This used low mileage motor hasn’t been run for over three years.

Re: Bleed air from fuel system?
 

Cycle the key a few times. You'll hear the pump come on and then stop when pressure is there. Turn key off, do it again. I did mine 3 times, then checked for fuel at the rail (there's a schrader valve you can check with between the two sides, closer to passenger side). After that, I fired it up and had no problems.

Re: Bleed air from fuel system?
 

First fire up went great! Such a relief. It ran ruff for a few seconds then smoothed right out. Magnaflow XL 3 chambers sound great although there's no tailpipes yet. Ran the trans through the gears then shut it down to put more trans fluid in. Went to fire it up again and had no crank. Panic set in. Then I put it in neutral and it worked. Simple fix to adjust the neutral safety switch. Warmed it up good and topped the rad up. Didn't appear to be any leaks anywhere which is always a relief. I cycled the steering back and forth and topped up the ps fluid. Later I noticed ps fluid under the truck. Damn! It's difficult to see where it's leaking. I assume it's where the high pressure hose goes into the pump. I put a square body fitting in the LS pump and used square body hoses to the 78 square body steering gear. Worse thing is it's a b**ch to get at the back of the pump and when I pull the line off I'm going to get more fluid dripping down making a mess. Gotta check the hose to fitting connection. Now I'm wondering if I mistakenly got a late model square body pump part and used early model hoses? or would it even go in? Maybe the o'ring?

Re: Bleed air from fuel system?
 

If you are running f-body accessories I've found it easier to get at the pump fitting by pulling the pump pulley. You can get the puller/installer from a parts store that loans them out or as I did just buy one. They aren't very expensive.
I like using -6 Teflon line on the pressure side and regular -6 line on the return. The -6 on the return side is tight fit on the resivoir nipple but it can be done. I use -6 adapters for the pump and steering box. Never had a leak.
Glad it started right up.