Manual Fuel Pump

[jlwelding]

My AirDog 150 has about 8-9 years on it and thinking it may die at any time. Whats the latest on the manual pumps and filter set up for it? 

 

Edited December 26, 2020 by jlwelding

[Mopar1973Man]

Personally I would rather keep the AirDog. I'm on my 3rd. 

1. First pump lasted 250k miles and 11 years.
2. Second pump was a 3rd gen pump and barely lasted 7k miles seal failed diesel fuel washed out the bearings. Towed home for $450 bucks.
3. CURRENT - 4G AirDog 165 pump head mounted to my filter base. Zero issues. 

Mechanical pump I feel are too far from the fuel tank. (Personal). The other problem is there is no way to reprime if you get air in the system. There is no priming pump to refill the system. Pumps are design to PUSH fuel, not to suck on a 20 foot long straw. Give it a whirl some time put a bottle of beer on your rear bumper and stuff a 1/2" hose in the bottle and suck, boy, suck! You'll understand after trying. Always best to have the pump as close as possible to the fuel tank. 

 

The Current job I got in the yard his previous pump was a belt driven and got fed up with fuel pressure problems (regulator sticking open and dropping the fuel pressure) and went back to FASS 150 (even warned the owner about this). That pump last barely 100 miles and the FASS is at ZERO PSI and failed took the VP44 for the ride with P216 and P1689 codes. (His truck died 2 days after warning him 100 feet from my driveway.) Sent the pump to FASS to be replaced and the VP44 back to Power Driven Diesel.

 

Even while on the the phone with FASS I showed them how to fix this problem so they might actually take me serious about striking filters tires flinging debris at the filters and pump. I explained about anything hang below the frame for offroad use and being in the damage path of the tires. Hence while motors are ruined with snow and water slung at them for years, filter being pulled off and hit by debris.

 

But who knows... 

Edited December 26, 2020 by Mopar1973Man

[01cummins4ever]

 

 

The reliability of these mechanical pumps are second to none, and absolutely no problems on the suction side, these pumps would suck a golf ball through the line then chew it up and spit it out... lol.  All kidding aside they are really durable and as far as priming goes, that is not an issue, as long as your fuel system is tight their is no need for priming, and if you ever have the need to prime the system it is very  simple and straight forward, 

 

I have no regrets about getting away from the electric fuel pumps, These mechanical pumps been in existence for around 15 years and failures are something you don’t hear about, just makes fuel delivery something you don’t really need to worry about anymore as I’m sure other people who have installed these would agree 

 

 

 

[wil440]

On 12/27/2020 at 2:03 AM, 01cummins4ever said:

 

 

The reliability of these mechanical pumps are second to none, and absolutely no problems on the suction side, these pumps would suck a golf ball through the line then chew it up and spit it out... lol.  All kidding aside they are really durable and as far as priming goes, that is not an issue, as long as your fuel system is tight their is no need for priming, and if you ever have the need to prime the system it is very  simple and straight forward, 

 

I have no regrets about getting away from the electric fuel pumps, These mechanical pumps been in existence for around 15 years and failures are something you don’t hear about, just makes fuel delivery something you don’t really need to worry about anymore as I’m sure other people who have installed these would agree 

 

 

 

Same here. Mechanical is the way. 

Only time you need to prime is the first dry time and if you ever do it takes a couple of minutes anyway. 

Never have to worry about fuel pressure again 

[Mopar1973Man]

Just wait till the day and the return tee starts to leak air. Oh the sealing washers at the back of the head are leaking. Crossover tube o-ring failed and you now lost prime you not starting and it can randomly happen. I've seen it happen even on my truck which I see the fuel pressure fall flat to ZERO as the electric pump tries to reprime. Mine will start again. But mechanical pumps will not, kind of like when the stock block mount pump dies. No different. 

[wil440]

8 hours ago, Mopar1973Man said:

Just wait till the day and the return tee starts to leak air. Oh the sealing washers at the back of the head are leaking. Crossover tube o-ring failed and you now lost prime you not starting and it can randomly happen. I've seen it happen even on my truck which I see the fuel pressure fall flat to ZERO as the electric pump tries to reprime. Mine will start again. But mechanical pumps will not, kind of like when the stock block mount pump dies. No different. 

I'll take my chances with the mechanical

[Tractorman]

What really makes no sense to me is why did Cummins drop the OEM mechanical pump when the 24 valve engine came out?  Not only was it a very reliable lift pump, but there was also a hand operated plunger as part of that pump to use for priming when necessary.  It would seem that the pump could have easily been modified by Cummins for the flow requirements of the VP44.  Then the wheel would not have had to bee re-invented and all of the lift pump issues for the 24 valve engines would have never happened.

 

- John

[IBMobile]

3 hours ago, Tractorman said:

Then the wheel would not have had to bee re-invented 

For Automotive engineers this is call job security. 

 

I have a cheap Airtex lift pump plumed into the system if I need to prime, like when I replaced the VP44 and then again with the injector change out; other wise the fuse is pulled and it just along for the ride.    

[Tractorman]

2 hours ago, IBMobile said:

I have a cheap Airtex lift pump plumed into the system if I need to prime, like when I replaced the VP44 and then again with the injector change out; other wise the fuse is pulled and it just along for the ride.

 

That sounds like a good solution. 

 

I probably would have gone to a mechanical pump for reliability, but since my original VP44 and lift pump were replaced under warranty way back in 2005, I stayed with the in-tank lift pump and fuel pump relay provided by the Dodge dealer.  I have since removed the in-tank lift pump and mounted a used frame-rail FASS DRP-2 lift pump with a coarse screen on the suction side.  I still use the stock fuel filtration downstream of the lift pump.   I did this mod in the Spring of 2016, almost 100,000 miles ago.  I carry another used FASS lift pump with me for an emergency roadside replacement if necessary. 

 

- John

[Mopar1973Man]

12 hours ago, Tractorman said:

What really makes no sense to me is why did Cummins drop the OEM mechanical pump when the 24 valve engine came out?

 

Because they total screwed the pooch on that pump. The pump actually only pumps as the piston returns back out ot the cam so at 3,000 RPM that old 12V mechanical pump is only 10% efficient. Lower RPM's it does very well but at faster RPM's the efficiency drops fast and hard because the pump piston can 't return fast enough. Hence why guys that truly race 12V don't run the mechanical because it will starve out the p-pump. Daily drive those are fine but not good for any type of racing or high RPM uses. 

 

The cam pushes the pump plunger in and it pumps on the return stroke so if the cam is spinning too fast it only hops on the tip of the lobe being that the return spring is doing the pumping till the plunger makes contact with the cam again.    

 

As for the first gen the fuel pump is not high enough volume rate and only produces about 4 to 6 PSI total. This why the 1st gen was dropped because the volume of the lift pump and the limit of VE pump was good enough to keep up with HP. So the p-pump came out. 

Edited December 29, 2020 by Mopar1973Man

[Doubletrouble]

 Was that a change made by Cummins or dodge? 

[Mopar1973Man]

I would have to say more so Cummins. Still in all the mechanical pump did poorly for volume. 

 

Here is the article on the mechanical pump and how poor they are...

http://www.torkteknology.com/technical-article-1-cummins-lift-pump/

 

 

Hence why most pull the mechanic pump off and install a FASS or AirDog with increase pressure spring for the P-pump requirements. Kind of hard to compare stock Cummins lift pump of mere 2.36 GPM (calc) or 0.44 GPM (actual) to AirDog or FASS at 150 GPH (2.5 GPM actual)

Edited December 30, 2020 by Mopar1973Man

[Doubletrouble]

 I was curious since I read somewhere that once Cummins supplied the engine dodge did a few things that fell short of the requirements. Can't recall what they were at the moment. I know the engine itself is a very solid and reliable foundation as long as it is fed properly. The dodge parts of the vehicle wear out before the engine does.