4/28/2021 HP FUEL PUMP FAILURE AFTER UNRELATED ENGINE WORK ... - DTNA Solutions

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et ; y Grant_Overton

=’ Wrench Turner
03-30-2017 10:35 AM

HP FUEL PUMP FAILURE AFTER UNRELATED ENGINE WORK
FINISHED,

WE have seen this severaltimes, now once a cylhead is removed for internal engine
work or camframe reseals, you goto start the truckand hp pump will not build
pressure, fc 157/16 for low rail pressure allof asuddencomes active, the only thing done
to the fuelsystem was _ retre fuelrail.and hp lines, and now thecustomer needs anew
pump, t/shoot tree has youreplace plv, metering units and rail pressure sensors, about
1500.00 worth of parts and then data log and ddec reports are up loaded to csc, where
csc instructs youto "try"a new hp pump, this fixes the issue, but it doesn't explain why
the truck all of a sudden needed apump it droveinfine, hadnoissue before we
separated the hp fuellines, and now itneedsa pump. why,

my tech asked me"is there a way to cap off each hi pressure fuel line tothe pump and test
each side of the pump duringatensecond cranktest toseeif one side of pump is failed
before you replace allthe plvand sensors and metering units, and not incurring additional
1500 dollars of un-needed parts inthe repair,{ parts not returnable once installed. }

Will capping off the lines on the pump individually hurt or damage the pump. willit show a
plunger failure separately inthe pump.

let me know and maybe add this to t/shoot tree if it works, we had over 10 hrs of
diagnostic time with all the datalogs and road tests, inlast 157/16 t/shoot then replaced
the pump, for6.0 hrs, total of 17 hrs,

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Mast, » « Robert_Cadell_J
© Te. =
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4/28/2021 HP FUEL PUMP FAILURE AFTER UNRELATED ENGINE WORK ... - DTNA Solutions
03-30-2017 04:00 PM

Piece of advise if you have metal in the fuel or your sure it's a HP pump failure find the old
recall bulliten for checking the plungers disassemble the pump, if you see the damage take
pictures of it, email them to your warranty administration and attach them to the claim, since
we started doing that and marking our pumps, not one claim has been denied also don't forget
if it's a metal issue to pull and clean the tanks, and yes Steve we've had that problem during can
housing reseals too

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&,
T

Tech

@ = Robert_Cadell_J
MacGyver
03-30-2017 04:05 PM

Grant to answer your question we have seen that too | think the injectors are air lockingg
somehow as far as the pump, not sure to Scott tripell's point he's right they are trucks stop
worrying some questions we just won't have answers to unfortunately

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=F vy Grant_Overton

‘/ E
=" Wrench Turner
03-30-2017 04:58 PM

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4/28/2021

HP FUEL PUMP FAILURE AFTER UNRELATED ENGINE WORK ... - DTNA Solutions

you missed what | was after , if you have low rail pressure fault code, if the plv has onlya
few blow offs,(15) it most likely isn't the cause of low rail pressure reading, the engine runs
smooth at idle, so metering unit is out, so fsic, test ,

so t/shoot starts with plv,fsic, then airinfuel ,and test mcm,and then rail test and
injector leak down test, thenpump bar test ,

so if bar is 400 psiand holds, it would indicate pumpis good , but youcan get 400 bar
off one pump element, the other may be failed, now you bypass the pump as the cause
and waist more time going elsewhere, running datalogs and sending reports tocsc, so
why cant you cap off each hp line and check pump elements that way to seeif both side
of the pump are to spec, individually, you have the rail capped off todo the pump bar
test , why not test each pump element by capping each line off and seeif pump is good, .
you can't pull pump elements in chassis, ref campaign 10c4

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asta, @ - Robert_Cadell_J
— MacGyver

03-30-2017 05:22 PM

| seen your point | agree with you, we can't cap off either side of the pump to check the
elements and here's one, loss of prime get to the point of a possible seal with in the pump, the
low side test passes, I've asked the question why can't we vacuum the system ?

We haven't had good luck with the low side tests

Rob "Doc" Cadell

Diagnostic Technician
TransChicago Truck Group BFWD
Shorewood IL 60404

803 917 5397 cell

Keep digging you'll find the answer
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| J Grant_Overton
ae

‘=’ Wrench Turner
03-30-2017 06:12 PM

(allthis is based onno metal contamination in filters or rail. )

t/shoot tree has you dead head the pump doing the 10sec crank rail bar test, as all inj lines
are capped on the rail, so capping the 2 hi pressure lines at the rail connection, one at a
time should give usa bar reading for each element, this should tellus if one or both
elements are making pressure, wouldn't it?

As incampaign10c4 the pushrod inanelement may be broken but still functioning, but
not to spec, but since you cant pull the elements in chassis, would this cap test check the
pump witha quick cap off test onthe twohplines and confirm pump is failed before pulling
it.

since CSC advises once you have exhausted and replaced the all the fuel components,
under current tree to replaced ,, to "try a hp pump" the quick crank test with each hp line
capped off at hp lines should be a better test than throwing anew pumpatit. if it comes
up low on one side or the other ,or below 400 on individual, we would have a better idea If
pump is actually failed, than throwing 2300 .00 more at the issue,

with current tree we are atabout 14-15hrs, customer is stuck with a1500 .00 un needed
parts ontop of the 8hrs of t/shooting and thenthe cost of a pumpif needed, + 6 hrs to
rt+r pump.

Where he could have been billed for the 6hrs toreplace the pump and most likely about
2-3 hrs t/shooting, for fc 157/16 low rail psi, witha low plv count , to cap off inj lines and
test hp line separately on pump to confirm both elements are pumping would take 1, hr
approx. after the first few steps of low rail psi t/shooting,

What if putting a pump on didn't fix it, there is no way to test the pump pressure per
element off the truck, now customer is stuck witha new S$ 2300.00 pump on top of the
other $1500.00 unneeded parts, .

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@ = Robert_Cadell_J
MacGyver
03-30-2017 06:23 PM

Tech

True, one other thing if I'm not mistaken t/s shooting never asks is the condition of the fuel
example water, fuel is a yellow color, excessive additives which will cause injector damage and
misfueling and my personal favorite biodiesel blend. | 5hink detrois recommends no more than
a 10 percent blend but NO station is regulated. Look at the stickers may contain 5 to 20
percent blend.

With this being said are our parts failing or is it time and mixed along with poor fuel.

Just something to think about.

Rob "Doc" Cadell

Diagnostic Technician
TransChicago Truck Group BFWD
Shorewood IL 60404

803 917 5397 cell

Keep digging you'll find the answer

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ie ™ Ai) Shadowlawn_Pens
5 Apprentice
03-25-2021 07:05 PM

| like this post right now,

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4/28/2021 HP FUEL PUMP FAILURE AFTER UNRELATED ENGINE WORK ... - DTNA Solutions

| have a p3 inthe shop right with a bad cam housing gasket, we replace the gasket (per
customer also all 6 injector ) put the unit back together, start the unit , engine fire on the
second start ,but only ran for 1 min, we went back basic check for fuel leaks, ect ect , connect
the computer and notices no pressure on the fuel rail, but no code , after troubleshooting the
fuel rail pressure , we replaces the PLV , that fix the pressure issue at the rail, try again and
the truck sound like it want to start but it doesn't, continue the troubleshooting end up
replacing the pressure relief valve , two step valve and the fuel pressure sensor in the rail, but
still no start , | have O pressure on the low pressure fuel pump , but my high pressure pump
since to be working fine , what can | do next ?

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wi Daniel_Collins]

a.
“iJ Lube Tech

04-05-2021 10:15 AM

just curious how yall are priming the fuel system after all major work is done

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