Mechanical Fuel Pressure line bleeding?

[fj40dave]

Hi All...

Since I own a VP44... . thought I better get a fuel pressure gauge.

Ordered up the Di-Pricol mechanical set-up with the 18" pressure line and Banjo bolt upgrade from Geno's.

Question is: How do I bleed the air out of the assembly once it's installed?

Also... . anyone have links to photo's/web sites with this similar set-up..... pictures work great for me!

Thanks,



Dave Alberts

2001 Quad 4x4

 

[Jeff Clark]

*

 

[fj40dave]

Hi Jeff... .

I do have the isolator... . it's scheduled to be connected to the 18" line, then the white hard plastic tubing will go through the firewall and to the back of the gauge... . I'm wanting to see the pressure in the cab.

I had a lift pump fail just after I got the truck new - and since I'll be buying my parts soon enough (60k miles on it at this point)... . saving the VP44 seems reasonable.

 

[Jeff Clark]

*

 

[Proram]

Bleeding fp line.

Your wasteing your time, theres no reason to bleed the line between the VP and the isolator , it'll self purge it self, the gauge'll read w/ the air pressure as well as the fuel, think of it, you ever bleed a mechanical oil pressure gauge? nope? works same way, no need to waste your time. every time you shut the truck off the line will drain anyways.



Scott

 

[Jeff Clark]

*

 

[David Oxland]

I wouldn't bother bleeding if you can get away with it. Any air in the line will act as a buffer and stop pulsation and save the gauge . Any little bits of air that come out in the system will almost for sure return to tank without getting near an injector line. .

 

[Jeff Clark]

*

 

[PRout]

What's the deal with all the * 's ??

 

[fj40dave]

It sounds like the air acting as a buffer might be a good thing... .

I had searched through the archives and read about noise and massive gauge fluctuations... . hope I have neither of those issues.

Dave

 

[Dsl_Duo]

Looks like Jeff is editing all of his comments out and replacing them with an * ...



Must be TOP Secret stuff. If you see it you'll have to be silenced!



Dsl_Duo

 

[JB @ C and L Machine]

Are you guys talkin the line from the port to the isolator or from the isolator to the gauge? I been running one for 4years now

 

[fj40dave]

So... bleeding the line is "optional" and part of the learning curve for me it appears... . cool..... love lernin new stuff... .

Second Question:

I just got the bigger banjo fitting and seals from Geno's... . what are the recomendations for the source line to the gauge; off the bottom of the fuel filter-to-VP44 or from the VP44 Schrader outlet?

Dave

 

[Jeff Clark]

Originally posted by Shortshift

What's the deal with all the * 's ??

I answered fj40dave's question and then was told it doesn't need to be done, so I took back all that I said. I had to replace the text with something or it wouldn't let me edit my post.



BTW, with the isolator the air/diesel will never reach the gauge so the air will not act as a buffer against the gauge. That's why you have to be careful assembling the line from the isolator to the gauge. It's filled with antifreeze. The last fp gauge I bought came pre-assembled so that there was no air in the line. The one I have now did not come assembled and the instruction explained how to assemble it so that there would be no air in the line between the isolator and the gauge. But if everyone says it's a waste of time and doesn't need to be done, then don't do it.

 

[Proram]

FP gauge

Jeff , sorry if i worded it wrong, you ARE correct on the purging the air between the gauge and isolater, that MUST be done for the gauge to work properly, just on the vp to isolater line you don't have to bleed it, any small amt. of air will help to buffer the pulse from the VP.



Again sorry for the miss wording.

Scott



fj40dave, the best IMO is the tapped banjo bolt from geno's (or simalier) then just use an 18" grease gun hose you can get at any parts store, from the VP to the isolater.

 

[fj40dave]

So, it looks like the bleeding of the line from the VP to the isolator isn't critical and that a small ammount of air in that line will help with the pulsations. It appears the line from the isolator to the gauge (in the cab) needs to be air free... .



I have the threded/tapped banjo from Geno's - got here yesterday... . wondering if I should place it where the schrader is on the VP or on the outlet side of the fuel filter (I read that it's possable to do the outlet on the fuel filter in a search)... . ?



Dave

 

[Proram]

I think it's a matter of convience as to which port ya use for the tapped banjo, 1 thing is run a tap through the banjo, the inside threads heae been known to not bet quite free of plating, and when ya install it be GENTLE, especially if you put it in the VP , you'll strip the threads out the VP in a heart beat. (not sure of tq. , but it ain't much!) good and snug is my best way to describe it. Good luck, and oh yea your correct on your first paragraph.

Scott

 

[fj40dave]

Proram... . thanks for the info on the Banjo... . I'll run the tap through it as you suggest.



I'v read that 18 foot pounds is the recommended torque - with that amount feeling rather excessive..... so, I think I'm gonna do the "calibrated elbow" method - use my experience and not try to get this on too tight at first - always can tighten a little more later if it leaks... .



Dave

 

[Rman]

Jeff, I jumped in on this late. You don't have a copy of what you said do ya? I'm researchin and would like to read what you wrote about purging the air... from what I gather you did post something to that effect. PM if you don't want to publicly post it.