hfcm replacement

[04cr450]

Im not positive if my fuel pump is going bad or not, installed fuel pressure gauge and it fluctuates from 0 psi to 70 psi while giving it 1/4 throttle(idling the gauge shows 68 psi)... Im going to relocate the new sender i got first then if thats not the problem i guess its a new hfcm replacement. Question is for those who have replaced them any tips? Are there any o-rings i need to replace when removing the quick connects? thanks.. Also any suggestions to the above problem im having? Trucks runs very well, i have talked to a couple people about this and they all think the sender or gauge.. Just preparing myself for a new pump if needed. Thanks

[cRaZy8]

Pump swap is easy. Couple studs hold it to the frame.
I dont like the fuel line disconnect wrenches.
I use the cheap plastic ones from Napa, like $4 for the pack of 6.
They are easier to get into place, not much room to work.
Its a bit messy, and dont wear long sleeves lol.
Took me about 20min to remove and replace, laying on my back.


If your truck was dropping to 0 psi, it would fall on its face. It would have no throttle response. And most likely your injectors would be yelling at you by now.

[kendallcschm]

Originally Posted by 04cr450

I'm not positive if my fuel pump is going bad or not, installed fuel pressure gauge and it fluctuates from 0 psi to 70 psi while giving it 1/4 throttle(idling the gauge shows 68 psi)... Im going to relocate the new sender i got first then if that's not the problem i guess its a new hfcm replacement. Question is for those who have replaced them any tips? Are there any o-rings i need to replace when removing the quick connects? thanks.. Also any suggestions to the above problem im having? Trucks runs very well, i have talked to a couple people about this and they all think the sender or gauge.. Just preparing myself for a new pump if needed. Thanks

it sounds like a fuel pump issue.. if it is the HFCM you could always just do an Airdog II lift pump to prepare for future mods.. it even filters out air bubbles.. try doing the FPR blue spring upgrade and see if that's the case.

[04cr450]

I have a blue spring mod in there(bout a year old)... The only mods i will do is get a bigger turbo in future along with studs.. Already have 155cc injects.. Its just hard to believe my pump is going bad.. The truck jumps and goes with no hesitation, runs to good ya know?

[04cr450]

wouldnt the airdog be a bandaid if the hfcm was in fact going bad? Or are you talking about the all in one airdog system? Dont think i want to go that route, to many problems and with my novice modifications, the stock pump is plenty?

[onebadcoastie]

My HFCM went out and I noticed fuel system issues 2 days out. It basically felt like I was running on empty in the tank. It didn't just die completely. It took a couple days. I had it towed to the dealer since when I called them from the parking lot to make sure I was purging the system right (which he argued and argued with me before realizing I was talking about a 6.0 and not a 6.4). He put the machine on it, called me and ordered the pump. The only thing I would have done differently is not have him order the pump. I would have purchased it from Tousely, AutoFair or Sunrise because their price with shipping would have been cheaper than what I paid.

[PGreenSVT]

Originally Posted by kendallcschm

it sounds like a fuel pump issue.. if it is the HFCM you could always just do an Airdog II lift pump to prepare for future mods.. it even filters out air bubbles.. try doing the FPR blue spring upgrade and see if that's the case.

Geez man where have you been? Everybody and there brother has a bad ADII DF-165. Strictly Diesel quit selling them because of the miserable failure rate and Pure Flow is denying there is any problem. If you are looking for reliability the ADII isn't the way to get it.

The Airdog 100/150 feeding the HFCM doesn't seem to have the same issues but the Airdog II high pressure pumps suck.

[kendallcschm]

Originally Posted by 04cr450

wouldnt the airdog be a bandaid if the hfcm was in fact going bad? Or are you talking about the all in one airdog system? Dont think i want to go that route, to many problems and with my novice modifications, the stock pump is plenty?

I'm talking about the full airdog II system.. it might be a tad on the overkill side but hey, if you ever wana go further you already got it there.. if your gonna replace something (and the OEM HFCM is 600) then why not with an upgraded part? my motto is that when the stock part breaks its an excuse to get a better aftermarket part

Originally Posted by PGreenSVT

Geez man where have you been? Everybody and there brother has a bad ADII DF-165. Strictly Diesel quit selling them because of the miserable failure rate and Pure Flow is denying there is any problem. If you are looking for reliability the ADII isn't the way to get it.

The Airdog 100/150 feeding the HFCM doesn't seem to have the same issues but the Airdog II high pressure pumps suck.

i've heard really good things about the ADII and FASS systems.. and i have read about alot of guys on other forums running them

[04cr450]

Ok, yes like i said, the truck is operating great. Idle is at 68-70psi, and 1/4 to half throttle is when the gauge goes crazy, you cant even see the needle thats how fast it moves lol (0-70psi).. I never go full throttle so couldnt tell you what it does then- would rather not until i know the fuel pump is good. We will see hopefully this new sender relocation works first.. Anymore advice would be appreciated

[04cr450]

tousley sells the whole hfcm pump for $272.50... Hey Mitch chime on in here bud!