High Pressure Pump Harness Shorted

[joshbuys]

08 F450, Died while idling, cranks but won't restart. FRP builds to 215 psi, Fuse 74 blown. Pump wiring shorted - chaffed. Pin 2 to ground - 1.7 ohms, pin 4 to ground - 4.2 ohms. TSB 07-26-02 says if one of the wires is shorted then just replace the pump. I'm good with that, but what if both are shorted? TSB states that the pumps are not being damaged.

Hotline says regardless of chaffing, pump IS NOT DAMAGED.

 

One of the guys I work with had one a while back that was chaffed on both wires, hotline said put just the gasket in. Truck died on test drive and guess what.....Cab comes back off for HPP....work twice....pay once.....

 

What would you do???? I've got it apart now, and both solenoids measure proper specs - 2.7 ohms on one and 2.6 ohms on the other. According to PPT ME this is in spec - (1.5-8 ohms). I'm just worried I'm gonna have to pull it apart again to do the pump, but only get paid for it once!

[Keith Browning]

TSB 07-26-02 says if one of the wires is shorted then just replace the pump.

 

There's your authorization and documentation.

[Jeff_E]

Quote:

TSB 07-26-02 SERVICE PROCEDURE

Unplug connector C1926 near the high pressure fuel pump cover.
Check pin 4 green/white and pin 2 yellow wires for a short to ground.
If either one is shorted to ground, remove the high pressure fuel pump cover and replace the pump cover gasket/harness that contains the grounded wire ONLY. The high pressure fuel pump does not need to be removed and replaced. Refer to the Workshop Manual (WSM), Section 303-04C.
When removing the low pressure fuel lines and high pressure fuel tubes from the high pressure pump, use a back up wrench on the high pressure pump fittings to make certain that the fittings are not loose as the cap nuts and high pressure fuel tubes are removed (this may cause a fuel leak).
When installing the new high pressure pump cover gasket/harness, verify that the VCV wires are wrapped in either high temperature convolute or a mesh style abrasion wrap.
When making electrical connections to the high pressure fuel pump, pull the connectors to verify connectors are locked in place.

I would be fearful of a kickback if I replaced the pump right off the bat. If it were me, I'd just do the gasket. If it dies afterward on my road test, I'd have the writer open a new repair order so I could get paid twice for doing it twice. Good luck.

[joshbuys]

Originally Posted By: joshbuys

TSB 07-26-02 says if one of the wires is shorted then just replace the pump.

 

There's your authorization and documentation.

typo....it says just replace the pump cover gasket. guess i got ahead of myself in my typing there.

[Aaron]

There was just a broadcast message regarding this, stating that guys are replacing pumps when doing the gasket and evaluation at WPEC is showing there is nothing wrong with the pumps.

 

But I hear where you're coming from...I've done one of these before and I was leery of the whole works just replacing the gasket until I saw the truck drive away.

[Keith Browning]

Kind of a difficult decision to make eh? For me finding a chaffed wire is usually enough as I like to find the actual problem. It is when you start reading things like this from any source the seeds of doubt are planted. Then the fun begins because the clock will screw us all any time we have to re-trace our steps. Personally I don't see how grounding any of those circuits is going to damage the pump. I HAVE had (and got beaten up by) a bad pump that acted just like the gasket harness chaffing symptoms. A faulty PCV or VCV OR a shorted circuit can do some strange things AND not leave a DTC.

 

Isn't this FUN?

[Aaron]

Put the pump in a vise, and spin the pump with no fuel in it till it stops turning LOL

[slim]

I've done several with no problems. I think I read somewhere that whoever manufactures the pumps was worried about the solenoid being grounded and the pump run at full pressure causing damage to the pump. After inspecting several pumps they said it didn't cause damage. That's just what I hear. Removing the cab isn't that bad the second time around-unless you put new bolts in like you're supposed to.

[eastendpowerstroke]

unless you put new bolts in like you're supposed to.

NO NO NO!!!!! you gotta replace them it clearly says so in the WSM..... just wire wheel the locktite off and antiseize the threads!

[joshbuys]

if you put heat to the bolts and a little pressure on the cab(start lifting) you can usually get them out with a ..... half inch impact ssshhhhhhh don't tell anyone. don't use the impact on the front two....i don't know why, but i haven't had any luck with those, start them by hand and then use the 3/8 cordless to finish 'em off. if they do spin, bend a 22mm wrench at a 45 degree angle and you can easily hold the top after removing the headlamps. Heat the loctite on the new ones and run 'em all in with the impact. occasionally one spins coming out, but they're all easy to get to..

[joshbuys]

Well...gasket in, 20 mile test drive good to go....guys looking at trading it off already. Go to my box to see what got drug in over the weekend, next in que - 2008 F550, died while driving, cranks but won't start.....hmmmm sounds familiar - pull codes, do tests and wouldn't you know it.....here we go again!

[mchan68]

Well...gasket in, 20 mile test drive good to go....guys looking at trading it off already. Go to my box to see what got drug in over the weekend, next in que - 2008 F550, died while driving, cranks but won't start.....hmmmm sounds familiar - pull codes, do tests and wouldn't you know it.....here we go again!

Reading posts like this makes me REALLY GLAD that I don't see any 6.4Ls darkening my doorstep for any driveability or starting concerns. The only 6.4L stuff I have under my belt to date are, rads, a couple of EGT_13s and couple of EGR valves. Hardly makes me a 6.4L guy.

[Aaron]

I am having a run of belt tensioners, front crank seals, and particulate filters.

[welzea]

Come on now Josh give my full story... before the "updated" harness" were available to me I put a pump cover gasket in... after 2 test drives of about 15 miles total, truck died and no restart... had to go back in and do the pump itself, I think more the dealer being in an audit situation was what made them tell me too bad your doing it again and not getting paid for it... but really I was seeing I was hourly at the time. ANd how about the pump cover gasket I am currently doing? It is the updated gasket with the wire covering and it chafed just to the one side of the covering where the covering stopped... that is awesome...

[Mikill]

I have seen a couple now with updated harnesses with chafes on the red and orange wires that are exposed on the bottom.

[dieseldeitrick]

I have a question about removing the cabs. So far I have done quite a few cab offs and overall had pretty good luck thanks to all of my resarch tools I felt very confident even the first time. Although, I have reached a new level of concern after leaving work yesterday>>>>> I have an Armored truck( machine gun on top) F-550 originally in my bay. I am lucky because the nearby Military base will be sending a bunch of these over, I suspect I will get good at these. QUESTION? There is NO possible way to remove this body due to obvious reasons as well as weight of the body. Can you actually put on the harness in question without removing the cab? I have one on the hook with the symptoms. My guess is they should be using an E-Series for this vehicle,but had to use a F-Series due to weight load. Does anyone have any ideas? Thanks

[Keith Browning]

Picture?

[joshbuys]

I have done one through the back after removing the transmission - can torque the lines from the top laying over the engine, and from the backside. Little bit of a pain, but it can be done.

 

And how bout that picture!?

[eastendpowerstroke]

I have a question about removing the cabs. So far I have done quite a few cab offs and overall had pretty good luck thanks to all of my resarch tools I felt very confident even the first time. Although, I have reached a new level of concern after leaving work yesterday>>>>> I have an Armored truck( machine gun on top) F-550 originally in my bay. I am lucky because the nearby Military base will be sending a bunch of these over, I suspect I will get good at these. QUESTION? There is NO possible way to remove this body due to obvious reasons as well as weight of the body. Can you actually put on the harness in question without removing the cab? I have one on the hook with the symptoms. My guess is they should be using an E-Series for this vehicle,but had to use a F-Series due to weight load. Does anyone have any ideas? Thanks

 

[dieseldeitrick]

I will get pictures asap. thanks guys!

[Brad Clayton]

Drawings are always better than pics.

 

[Aaron]

Don't forget the Air Force uses these trucks too, but as illustrated by the smoke - NO DPF:

[dieseldeitrick]

Sorry about the pictures guys, I suck. I ended up talking the manufacturer of the truck. Lenco Armor trucks lencoarmor.com.

Guess the body does not come off, even if it did it would be too heavy for most lifts. It was a long journey working from the front as I removed just about everything and then a little more to access. The turbo just squeezed by the body to remove. It was an accurate diagnosis for the pump harness as the TSB suggests. We are very lucky as technicians to have such resources available to aid in our diagnosis. This one had just the slightest wear on the yellow wire in which explains the intermitt no-start and lack of power. It only took me approx. 32 hours to do the job. If you ask for any suggestions on this type of repair for this vehicle? I recommend avoiding the opportunity.

[Aaron]

Call in sick for a couple days.

[Aaron]

And in regards to your previous post...would you really want them to be using an E-series for this? LOL