Primary fuel filter bleed - diesel 6.2

[Subourbon]

Quick question folks

6.2 1982 suburban k20

Got a new water separator/filter
Wix 33123

I dunno when it's been changed last, but I got the part so I'm gonna change it and have peace of mind. There's no water in fuel light, it doesn't struggle to start or anything, but i havent changed it since I got it 3 years ago.
It's also not my daily so there isn't crazy mileage on it.

However, should I prefill the new filter before installation? Because my filter housing has 2 valves, (*****) 1 on top for venting, and 1 on the bottom obviously for draining.

Wouldn't I be able to just put the new filter in empty, open up the vent ****, run the lift pump until fuel Comes up through the vent **** and close it when I see my tell tale diesel coming through? Might have a rough idle for a bit or rough start, but, I believe my logic is sound, or if it isn't, I'd love to know why. The lift pump runs when I turn the key and cycle my glow plugs, that steady brrrrr in the background, so I'm gonna go ahead and say it's electric? Regardless, the pump cycles fuel from tank to injection pump, so it must be able to fill a filter that is before an injection pump.
I've yet to see anyone on youtube doing it this way so now I'm sorta second guessing myself.
Also, I don't have a Jerry can of fuel here so I'll need to go get one, and before I do I want to know why I wouldn't be able to do it the way I stated
Cheers everybody!

 

[Subourbon]

So... it censored c o c k.
I believe that is the name. Regardless, that's what the **** is. Let's just call them valves then. Lol

 

[Itali83]

Yes, if you indeed have an electric lift pump, put your filter on dry, and run the pump with bleeder open until fuel comes out. I would close the bleeder while pump is pumping just to force any air through and back the return.

This is not the factory set up or filter you have on there but it sounds like a good set up.

Ben

 

[Subourbon]

Oh yes definitely closing the vent valve while it's still running.

I'm confused what difference would having an electric vs mechanical pump actually be?
If there is a vent, the fuel will displace the air through said vent until fuel squirts out, I then close the vent, and the pump carries on moving fuel from tank to injection pump as though nothing happened.
So I'd be able to do it regardless of the type of pump, right?

No lol there isn't much factory left here. But it works!

 

[Subourbon]

Asking because there's post about people pressurizing their fuel tanks, vapour locking their injection pumps, the end of days. Like, how? It's a fuel filter between thr lift pump and injection pump, with a vent.
Anyways, had me second guessing myself so Im reaching out to the community to see

 

[MrMarty51]

This unit does have an electric fuel pump ?
I take it that it must.
Yes, open the top vent valve and let that electric pump run until the air is expelled from the filter. Close the valve, **** down the pump and then the truck should fire right up.
That style of filter can also be filled with fuel and then screwed onto the housing. Thats how we did it in the shop.
But, it still needs the air purged from the top of the fuel and the head space after it is screwed into position.

 

[Subourbon]

Yes it does, I hear it running while the glow plugs are cycling, so should be good tongo.
Yeah if I had a jerry can of diesel I wouldn't be asking myself the question. Jist gas for the lawnmower and snowblower. Don't think I'll put that in the filter lol.
Ok so you guys are confirming my theory. Just don't know why everyone says you must fill before installation

 

[Subourbon]

"My theory"
Hahaha, you know what nice mean. I just wasn't sure anymore.
I've argued with people who fill their oil filters before install. Insay you don't have to and they look at me like I have 5 heads. And there's 2 schools of thought with fuel filters toi, fill don't fill. Anyways m thanks everyone

 

[Subourbon]

Update, it's all good. Old filter out, grease the oring on new filter. Install, prime, with vent valve open, started right up not even a burp!
Thanks guys

 

[Itali83]

The reason you can’t do what you described with a mechanical pump is that for the mechanical pump to pump, you need to start the motor. And since you’ll have an air gap from the fresh filter, your injection pump will run out of fuel before the mechanical pump will prime the filter. You’d have to disconnect the fuel shut off solenoid so the injection pump won’t pump any fuel, crank the engine until fuel comes out the bleeder, then shut bleeder, hook wire back up to solenoid and then start the truck. That’s how it’s done with the factory style filter and mechanical pump set up.

Ben

 

[Subourbon]

Thanks Ben, I ended looking it up after, and felt like an idiot for asking.
I, for some reason, thought it was a type of pump, not what drive pump.
Geez those must be some rough starts in the winter with a mechanical pump.

And that also why my Haynes manual was talking about doing that, I was looking aroundnline whatre you on about lol.

That clears things up, hooray community help!

Thanks guys!