Engine/Transmission (1994 - 1998) 12 valve fuel pressure gauge?

[Reddog1]

Is there much value in having a 12 valve fuel pressure gauge? If so, what should you expect for pressures?





Wayne

 

[DonTX]

Well, for me it was the fuel filter status indicator that Dodge forgot. How else can you determine the filter status? Many people just wastefully change them often to insure that it is clean, but even then you never know when you might get a bad batch of fuel the day after you changed the filter. I have only changed my fuel filter once in nearly 100k miles, and that was just because I did not know how long it had been on there.

Is there much value in having a 12 valve fuel pressure gauge? If so, what should you expect for pressures?





Wayne

 

[tp0d]

Certainly cannot hurt. Don is correct, a gauge between the lift pump and the IP would be pretty useful. They do sell banjo fittings that are tapped for this purpose.

I`d figure a 100psi max, glycerin filled gauge to dampen spikes. May also want to investigate an isolating tube, to keep the fuel out of the cab. Typical fuel pressure is around 50psi give or take. .

-j

 

[Hammer]

Here is the thread that Jim did on his test gauge set-up.



https://www.turbodieselregister.com...-build-fuel-pressure-test-gauge-12-valve.html



To make a permanent guage would be easy,however its my opinion on the mechanical systems its a waste of time to make it permanent... ... . Andy

 

[LVJUNIOR]

Does anyone know what size the fitting in the banjo bolt on the fuel filter housing is

 

[Joe G.]

To make a permanent guage would be easy,however its my opinion on the mechanical systems its a waste of time to make it permanent... ... . Andy

I certainly don't agree with that. My fuel pressure gauge kept me from walking on a trip where the overflow valve decided to give up. If I didn't know that fuel pressure was down to 6 PSI I probably would have stopped at a rest stop. At that pressure it would not start again when I got home. That would have happened at a rest stop. A fuel pressure gauge will warn you when something is going wrong soon enough that you can get to a place to deal with a problem. It will also help you troubleshoot a fuel supply problem.

 

[DonTX]

I have got two from Geno's, they were both 1/8th pipe thread. It weakens the bolt a lot, so you got to be really careful when torquing it down.

Does anyone know what size the fitting in the banjo bolt on the fuel filter housing is

 

[WDixon27]

i am sporting one for the failure indicator function it can serve, i have my OF valve set to where it runs 25-36# depending on rpm and load which seems to be normal from what i have read about others set up's, it let me know when my lift pump was about dead, the hardware store needle valve is the way to go on dampening the pulses, the isolator that came with my isspro crapped after a couple years and the damper i got after the fact let so little pressure through it would take a few miles of interstate driving to get up to pressure and a while after shut down to drop

 

[Hammer]

So then tell me Joe...

On a 12v,how often have you actually had a fuel pressure issue that would warrant a gauge?.



Many 12v owners drive hundreds of thousands of miles with nary a fuel pressure issue and yet you feel its a necessary item for them. I would agree if they were using a electric system that could fail prematurely but with the toughness of the factory mechanical system being what it is,I stand behind my comment and repeat saying they are not a needed item for a 12v owner..... Andy

 

[Joe G.]

I didn't say it was necessary. I said I didn't agree that it was a waste of time or money. As I said above it saved me from walking one time when it would have been a big deal. Paid for itself that time alone. Other times it has helped me diagnose problems that would have been harder to find without the fuel pressure gauge. I also use it for fuel filter status as Don/TX described above.

 

[DonTX]

Hundreds of thousands of miles without a fuel filter change?!? Dayum, didn't know they would go that far, yet you say many do that?

I had a mechanical supply pump fail at low miles on a first gen, the failure then wiped out the injection pump. A pressure indicator would have saved thousands of dollars.

I have gone hundreds of thousands of miles without a charging issue, or a heating issue, and certainly not an oil pressure issue, but I still think that those guages will stay, at least in my truck.

So then tell me Joe...

On a 12v,how often have you actually had a fuel pressure issue that would warrant a gauge?.



Many 12v owners drive hundreds of thousands of miles with nary a fuel pressure issue and yet you feel its a necessary item for them. I would agree if they were using a electric system that could fail prematurely but with the toughness of the factory mechanical system being what it is,I stand behind my comment and repeat saying they are not a needed item for a 12v owner..... Andy

 

[Reddog1]

Interesting points made. I never considered using the gauge to monitor the fuel filter. I also wonder if the fuel gauge would have warned me that my fuel line needed attention, before it became critical? The fuel hose was cracked, and sucking air.


Wayne

 

[Reddog1]

Don/Tex, what is a MorRyde suspension?


Wayne

 

[DonTX]

Good Question. You can go to the Mor-Ryde site and see it in action. They make suspensions for larger motor homes, and this is a "ride softener" for empty one ton duallys. Essentially, you are riding on a rubber suspension block when empty, rather on the rather hard dually springs. Makes it ride like a Mercedes when empty! (well, not quite, but you get the idea anyway).

People generally come up with some sort of periodic fuel filter change, that makes no sense really. IF you burn clean fuel, the filter would in theory last forever. If you get a bad batch of fuel, you can be changing filter half way thru the tank. Changing out a perfectly clean filter makes no sense to me and does not insure you of anything - other than expense.

Oh yeah, here is a link to the suspension: MOR/ryde - Products - Suspensions - Tow Vehicles

Don/Tex, what is a MorRyde suspension?





Wayne

 

[CCiatteo]

I am going through all of this right now on my truck and ordered some new sealing washers, banjo bolts etc today. Tomorrow I'll post up all the Cummins Part #'s and what I paid for them. The local Dodge dealer was almost useless. They weren't real enthusiastic to help (but really wanted to sell me a new truck), had nothing in stock and told me everything was at least a week out???? So I went straight to the source and I'll pick it all up tomorrow for a fraction of the price. Details to follow... ...

 

[LVJUNIOR]

I took some advice I read here and got the fuel gauge kit from harbor freight and added the needle valve in line. The kit has a hose that fits the fuel filter blead bolt.

 

[CCiatteo]

Well this is what I have, all parts numbers are Cummins:



Banjo bolt at the Injection pump, from the filter head (the one commonly tapped for the fuel pressure reading)



Banjo Bolt, Part #3924725 $13. 25

(2) Sealing Washers Part #3918192 $2. 74 each



Banjo Bolt at filter head with bleeder (this is the line that goes to the injection pump). Mine is leaky so I picked one up while I was there.



Banjo Bolt, Part #3911446 $16. 79

(2) Sealing washers Part #3963983 $1. 27each

Bleeder Screw/with sealing washer Part #3939570 $2. 74



This is all for my 97, don't know if others would be different? I'll confirm this stuff fits as soon as I get it all fitted up.



Chris

 

[DonTX]

Photos would be nice, I just have to get off my butt and hook mine up one of these days, maybe you could give me that encouragement in photos. .

 

[RHestand]

On my 98 12V, I drilled and tapped my own banjo fitting, then installed a fitting and a copper line to it, then to a small, inexpensive, liquid filled gauge inside my cab.

If ever starts leaking, I'll either fix it, or take it out.

About two hours to install, and about $30 for everything.

I like knowing if, and when my fuel pressure changes, for any number of different reasons.

Ray

 

[PRohr]

The 24V banjo bolt for the FP tap that Geno's sells will fit right in the top of the FF cannister on the out line:



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Much easier than tapping the stock bolt.