How To Change a HEUI Pump. Cat C7, 3126, and C9

[@hunterharness]

Tappet wrench from a harbor freight air die grinder just saved me on the qd oil line Thank you for sharing your experience with me 🙌🏻🙏🏻🙏🏻🙏🏻

[@jasonkobbe4676]

yeah great videos..their isnt much diesel stuff like this on youtube im glad i found your channel

[@AdeptApe]

Thank you sir. I try to put up a video a week for my subscribers. Please subscribe. Thanks for commenting.

[@chrischupailo9956]

You do not need to remove the air compressor to replace the line. All you need to do is unbolt the power steering pump from the back of the air compressor (leave the p/s lines on) then all you do is remove the back side it's held by 4 nuts (13mm wrench) then you have access to the 2 Allen head bolts that bolt the line to the block. Then you replace the O-ring on the block and reinstall

[@C.O.SBurpees]

chris chupailo I had to replaced that oil line yesterday and I saw your comment and tried it out, it really helped out alot man instead of taking the whole compressor out just the power steering pump and the rear side of the compressor was removed made life alot easier thanks

[@davetuttle9701]

Great videos! I'd love to see a C7S Acert walk around and regen system diag and explanation, the common rail C7S.

[@henshawhench3654]

Great video definitely explain every step

[@dronez9047]

Ape I love your videos, starting a Diesel Fitting apprenticeship soon and all these videos are an unexplainable amount of knowledge! Thank you :)

[@AdeptApe]

+Dronez Thanks for watching them

[@zanestinnett6826]

​@AdeptApe need help. I have a 3406b the fuel pump is leaking oil from the back. Can i rebuild it myself

[@podlfksduesfe2539]

Great video man!, love all these videos on CAT engines gives me a better clear knowledge.

[@AdeptApe]

Thank you, I'm trying to slowly build a KZbin based repair base for Cat engines.

[@podlfksduesfe2539]

+Adept Ape well man keep those videos coming we all enjoy them

[@gabrielocampo2265]

Saved my day, Thank you!🫡

[@lekkousa]

Loved seeing the 3208 in the Suburban!

[@AdeptApe]

Thought a few people would find it enjoyable.

[@Olive-oilien]

Great great great videos! Thank you for what you do

[@smiley1612]

Did my first c7 HEUI pump the other day, same symptoms as this one. Great video, thanks for the tips!

[@collinsampson7868]

No did not the same

[@liltrelllactivv4146]

How long did it take? If you don’t mind me asking

[@twojs27]

N thanks for all that you do on youtube to help us out... awesome

[@arshingamini3025]

Jim McMahon inn N Injection actuation per Ensure

[@richiebledsoe1006]

Always great info totally appreciate your knowledge man!

[@wazza33racer]

makes sense to remove/replace the compressor and oil line when doing the pump anyway.

[@AERSLLC]

word of advice make sure to remove add thread locker and re-torque the drive gear nut. have found them lose or to become lose after a few hours of running. also had some come in with a lose nut on ones just replaced by freightliner.

[@AdeptApe]

I have seen a couple with that happen. What ft lb do you torque the nut to?

[@AERSLLC]

Adept Ape normally 125ft/lbs but now I just use a 1/2 impact wrench.

[@Razz-es9qw]

Replacing the injectors is only necessary if that solenoid itself fails and leaves metal shavings around the solenoid? Can contamination be seen through some of oil lines going into the cylinder head? Thank you for the informative video...

[@skwlogistics3698]

thanks for responding, I can't wait to see that video

[@AdeptApe]

I can't wait to put it up either, I've had tons of requests for it. I always try to respond to my subscribers.

[@rickl6697]

Josh, at 1:11 mark is that the upgraded high pressure oil supply line(solid steel vs. steel braided hose) you talked about upgrading in the get to know your 3126 video. Thanks. Trying to tell if our 3126e hose has been changed.

[@jorgeherrera2275]

Does the high pressure supply line to the head have any O rings or just the ones that sit on the connectors? If you could help please I’m in desperate mode I have had issues with this for about a year

[@waymaker109]

I have a C-7 in a 963 Cat loader crank, but no start, what's the differences between it and one in a truck?

[@Stevexnycautomotive]

The oil accumulator on the HEUI pump hold approximately 3000-3500psi of oil pressure to fire the diesel injector during cracking of the engine at startup. Hard start will occur if the accumulator can not maintain 3000-3500psi.

[@rickl6697]

Josh, the head on that new Heui pump looked cracked on the front (above the separation of the head and case), where your left hand is holding it. ??

[@elitetimberservices]

Can you use the other style huei pump that's available. Does it matter?

[@richardashman6990]

Do you have a video about replacing the flexible oil line going to the HUEI pump? The replacement line is a rigid steel tube assembly.

[@motox4150]

I think it has a filter as well.

[@piper4me584]

I'm about to purchase a 2005 Freightliner sportchassis with a C7 cat motor. Under 100k and lots of good maintenance and service records. My question is I read so many issues with the heui pump dumping metal into the fuel system and causing injector damage and replacement. Why hasn't anyone added a high pressure inline fuel filter from the heui to the fuel rail ? Is that even possible ? Very new to Cats, all my toys have DD 6-71TI's. Great video and thank you.

[@Hooptierescue]

that funny I used old mirror bracket just cut it where the bolt went work just fine great videos.

[@AdeptApe]

Thank you.

[@Backwater-wanderer]

Could you tell me where the fuel pressure regulator is on this engine?

[@debescuadro8052]

Hi, Can i ask about C9 engine, If we change new injector, It need also re-incoding the injector? Thnks for d answer plz,,,

[@cisco40tys90]

You the Man!!! Thank you for the video!!

[@AdeptApe]

You are welcome, hope it helped.

[@asgrowler]

really appreciate videos,, I have a c7 cat , and have No Fuel pressure , can you help

[@chriskinney7335]

I'm changing the pump on a 3126B. Different style than what's on the video. The oil line that comes up from behind the compressor is solid steel and makes it real tough to get the pump out.

[@chriskinney7335]

Got it. Had to keep removing stuff and prying just right.

[@AdeptApe]

+Chris Kinney They are tough to get, did it have the quick connect or the large steel nut? Having about every style wrench ever invented helps.

[@chriskinney7335]

Adept Ape large nut. One of those "keep trying" jobs.

[@momenkamel445]

Adept Ape sont pas

[@jorgeherrera2275]

I just replaced it but now I’m loosing oil through the blow by could it be related to the heui pump or any other suggestions highly appreciate it

[@matthewsandgren7598]

So I have a code 63 once in awhile what's ur opinion on changing the transfer pump on the back of huie pump?

[@melbreki3388]

I enjoyed the video and learned a lot, thank you. Could you tell me the part number for the sealing O ring on the pump. I ordered a pump but it did not come with the O ring

[@SteveKluver]

Thanks for this video! A big help. Especially the part about telling us that this unit is not timed. A nice little fun treat there at the end too! I am going to look at some of your other videos now. I'm hoping to possibly learn more about the engine/fuel injection difference between say a 190 HP 3126E, and a 330 HP engine. I have one Truck with a bad 210 HP 3126B (70 pin), and I'm hoping I can more or less easily swap in a two year newer (70 pin) 3126E, of 300 or (EMS) 330 HP. I'd sure love to learn more about how Cat gets 800 ft/lb, and 860 ft/lb rating out of the same engine. It seems they are selling a high, and low torque models?

[@AdeptApe]

+Steve Kluver Thank you for watching. The 3126 engine and head are all the same. The differences between a 190 hp and a 330 hp is the pistons, injectors, turbo, and possibly the damper, HEUI pump, or camshaft. Depends on what rating you are looking for. The newer 3126 should fit right in. Just check that the transmission can handle the torque.

[@SteveKluver]

Thank you. I am waiting on a call back from a couple of different dealers now. I must have caught them off guard, as I could hear them over the phone scratching their heads, during my questioning of a 70 pin 'E' easily going into a 70 pin 'B' engine bay : - ) Do you happen to know what the lowest HP rating is, that does have all the right hard parts, but is just cut short a bit, by the ECU tuning? 250HP?

[@AdeptApe]

+Steve Kluver I believe the lowest "high horsepower" is a 250 800 torque, but that is a C7. I'm not 100% on that I'd have to check, the 3126 engines had more variability. If you find one with either 800 or 860 torque then that is the high horsepower build and should be able to be uprated. If you find one send me the serial number and a new message and I can try to look it up and tell you.

[@SteveKluver]

I will do that. Thank you. PM coming your way.

[@AdeptApe]

+Steve Kluver I got your PM, I'll check the serial number for a rating. In the future you can send me emails directly at [e-mail] it is much easier than using the PM feature.

[@imran3055]

Can we open IAP control valve. For replacement???

[@ethanpaul7668]

How about a video of the 3126 with the bolts on the back of the heui pump

[@gaspargarcia4177]

Im about to change diesel filter can you tell me how to prime it or es electronic primed the engine is a cat 7.2 C7 hope you can help me!

[@zanestinnett6826]

I have a 3406b. The huei pump? Is leaking oil. Can I rebuild it myself

[@WorldsOkayestFarmer]

*Great video man! I watch a lot of them because I run two trucks with these engines. Just had a pump go out. Thanks a lot* #WorldsOkayestFarmer

[@primitivoortega265]

I have this code actuation pressure output fault ?????

[@jimmyjaan1493]

Nice information

[@kevinolson3030]

I replaced the transfer pump back of heui pump due to an oil leak on cat c7. Now I have an oil leak on the front part of the heui pump. Was wondering if the gasket is able to be replaced or need a new heui pump. Thanks

[@bagmann89]

I need help installed new injectors, fuel rail filters lines etc and still wont start

[@toledomachinery2189]

Good evening, I have a cat 140K year 2010, he is blowing white smoke through the engine breather, and he reissued valve guides, engine block, compressor, he changed rings, checked the engine liners. Bearings, even changed oil pump and pressure pump, but the problem persists, white smoke is still coming out of the engine oil nozzle. What I can do, changed almost everything, I only need to see the turbo, which advises me or which believes the problem.

[@rickl6697]

Can you replace a square head heui pump with the round head heui pump. I believe in a different video you said the round pump had less problems and you could replace the driver separately from the rest of the pump for a lot less money. I have a rv with a 330hp 3126e. Thanks

[@billhowe4863]

Is that fitting an stc?

[@kenherrod]

Hi. I have a 05 C7 not getting fuel. Ran great before it got 20 below a few weeks ago. Changed filters. Did not help. Ordered new fuel regulator. They sent the wrong one. Just took out the old one and tried to start. No fuel is coming out of the hole. Fuel gauge is showing 0 psi. Time for a huie pump or is there something else i can try first? Thanks for your help.

[@judelouigene2315]

thank you for this video

[@josephchurey1909]

My parents have a 2002 frieghtliner motor home with a 330hp cat 3126 every was fine with it until my dad fired it up the other day it ran for a minute and then shut off the fuel filter I drained the cycled the key a few times but it will not fill back up with diesel but fired up with a tiny bit of starting fluid any recommendations

[@zxstream]

I have a C7 in our RV that is now popping the CEL "94-1 Low Fuel Pressure Warning (63)". Does this sound like my pump is going bad? If so, how would I change it in a pusher Freightliner chassis? I'm pretty mechanically inclined but it sure is tight in there! Help from all is welcome please!

[@jerryw4458]

I'm trying to purchase a 2005 motorhome with a 350hp C7. This whole HEUI pump has got me scared. Is this a great concern?

[@ericbarkan1]

I have a question. I have a 3126 in my bus that has this same Heui pump. The rubber feed line is leaking a little (seeping). Is this something I need to address immediately, or is it ok to run it for bit while I gather parts?

[@antoniotrujillo547]

thanks for the info I'm been learning a lot i appreciate

[@1HSYURIDIA]

What's the trouble shoot for this ? Why this pump had to be replaced what's the simthoms???

[@1HSYURIDIA]

👍

[@rcmartinfarm3512]

My Sencer on top of heui pump is lose and has a slow oil leaking around it is that a problem ?

[@marcoknight4154]

Hey Ape!! Good tips you give here on your videos!! But i still have an issue i got this RV with a Cat 3126 and it wont start just cranks the tach does move and the oil press does move too. A previous tech says the fuel injector pressure is 200. What can you suggest it is?

[@bpatel4434]

Hi adept , I have c7 -190hp-freightliner straight 5ton truck . Problem - diesel in oil and low oil pressure Cat guys changed o rigs of injectors and now they are changing transfer pump . I am not getting any code. Cat dealer guys also confused about this dilution. Plz advise Thanks

[@joseamezola4345]

Okay I have a question I would appreciate your help I have a c7 in a 07 c7500 it is leaking oil from between the fuel transfer pump and the huei pump what is the process to stop it is there an o ring that seals it and do I need the fuel transfer pump removal tool from cat thank you for any help you can provide me

[@ameerbaloch4125]

Very good

[@ralphbaker9666]

Hi Adept Ape, I have a 3126B 8YL49553 330hp in a motorhome we had a lighting strike close to our house and ever since I can't get the rv started. The coach was plugged into the house for power like it always is. A cat tech guy came out and hooked directly into the ecm and said it was dead would not communicate with his computer. I ordered a rebuilt one from a company in Texas with life time warranty hooked it up and nothing same as old one. Have a pressure gauge hooked up to the high pressure rail and all I get is 200 psi, I know I need at least 850 psi to get it to fire. checked the fuse and ground and cleaned both, question is did i fry the new ecm is there some way to check wiring to find a short or what do i do. On a side note the lighting strike also took out the circuit board on the water heater. Help thanks Ralph

[@Davobeff]

What powers and grounds do you have into the J2 plug on the ecm?

[@ojongagodfrey7201]

thx for the lecture sir, i also have a problem with one of our wheelerloader 996h, showing three erro ,engine oil pressure,coolant temp,air flow, and engine has no power, pliz advice thx

[@TheGeneral100]

Hi What's the voltage I should read going to the fuel pump? I'm only getting 10 volts crank but won't start

[@shreeequipmens573]

Where can we purchase c9 engine heui pumps

[@kilroyjohnson6533]

Why is my oil not getting oil to the rockers and not starting?

[@maxxtech8532]

Is that solenoid inside the pump like an IPR valve? Seems like it has the same function.

[@darrelldoward5998]

Your videos are very good thanks you. I would like to know what I need to troubleshoot my engine? I have a 3126 installed in my boat and it is loosing power. Thanks Darrell

[@hectorgallegos5055]

Hey man got a quick question I got a c7 not firing all injector seals are leaking on the the top .. replaced all orings on all injectors tourque to spec and still leaking .not allowing oil pressure to build up and fire ..could I have a bad head ? Or maybe the bolts are too stretch 🤔,and not getting the right torque ?

[@treychastain4686]

On some models the injectors do leak excess pressure of out a weep hole.

[@ttompetty]

front housing cracked slightly, that isnt important for a good seal? at 4:53 i see small crack

[@AdeptApe]

+Art Huge I had to see what your talking about, that was probably a casting line, not an actual crack. That whole housing is filled with oil, so if it was an actual crack it would leak oil everywhere.

[@fourwayengineering5827]

hi sir hope you well thanks for making very good videos its a really big help . i like to know if you have made the video to replace the common rail fuel pump on C7S . please send me the link or just one qustion about the common rail fuel pump have timming or not ? thanks

[@boomstickkid]

is the air compressor timed on a c7?

[@datowing]

thank you for your reply when you open up the lines and flush the system you will be flushing out the oil side will it be metal in the return lines for the fuel tank I'm trying to figure this thing out I am a gas mechanic this is all new to me thanks

[@AdeptApe]

+duane addison You are only flushing the HEUI oil system, but the fuel system. You are basically blowing out the old oil and little tiny pieces of metal so it should pour out the back HEUI plug in the head and go into the cylinders. You'll have to evacuate the cylinders after which should remove nearly all the fluid and debris from the cylinders.

[@mattfrank5482]

Is the valve on top replacable . do they go bad?

[@dennya5916]

hey adept ape, i have a senor on the head of a heui pump that is leaking. I was looking at a parts book but just has the part numer to the pump. would you happen to know if there's a part number for the o-ring on that sensor? thanks

[@AdeptApe]

I know the answer to your riddle. So the electrical connector on top of the HEUI pump is for the driver/solenoid of the pump itself (should be a two wire connector). The oring that seals it is not in the Cat system, I know because I have tried to order it before. I'm sure if you removed it and tried to find a generic Cat oring of the same size, you might be able to if you had an oring kit. The HEUI connector is not replaceable either, so if that connector is bad then you need a new pump unfortunately. Did you ohm out the connector, if you did what was your reading?

[@dennya5916]

+Adept Ape at the connector it read 396.0 ohms

[@AdeptApe]

+Denny A The spec is 6-10 ohms of resistance, that is measuring the HEUI pump side not the wiring harness. If it's that high then the HEUI pump driver is bad, if you had HEUI problems that is probably the cause.

[@dennya5916]

+Adept Ape my bad check at the harness. It read around 13 but it was jumping all over.

[@AdeptApe]

+Denny A I know it's kind of hard to measure unless you have the little adapter. if you weren't having check engine lights or rough running then don't worry about it.

[@datowing]

hello how are you I would like to know where could I find the procedures to flush the C7 engine when it has metal in the injectors and Heui pump I have the replacement parts I just need to know what should I do to flush everything out before I install them thank you I looked for your link I could not find it

[@AdeptApe]

+duane addison Just remove all the injectors and one of the HEUI rail plugs and flush it out with brake clean or solvent. Then evac the cylinders.

[@richs5731]

I have a 2003 fl 60 with a 3126 E motor with a C 7 pump not a round top is this a better pump And can you add a jake brake to this motor

[@chriszorbas9415]

Hey great videos can't thank you enough! I have a c7 in a f750 truck runs great until the temp gets close to 180 then the truck struggles to build/jumps the rpms only when driving and idles a little shaky could this be a cause of the heui pump?

[@chichon1188]

Hey brother! Love you videos I’ve being watching all of them, now I have a question about the heui pump I remove the lift pump of the heui and I didn’t use the so call special bolt and all my springs and stuff I. The other side came out, I get to put it together but I heard that once all the springs and parts come out the pump would not run the same and I have to get a new heui pump?

[@cameronward7137]

Long shot but I have a c7 that looses fuel prime if it sits more than a day. What could this be??????

[@enginemaster01]

make sure and have new lines when doing this procedure. and this is easy. try doing on a c9 marine engine

[@adamh6507]

Can someone tell me the size of the opening on that tool? Trying to locate one for an FMTV in Germany, it's an impossible task. Need to fabricate.

[@meenakshimeena2014]

Oh very good video tankyou

[@3pRanchTx]

I own a motorhome with a C7. I read in an RV forum that it is a good idea to clean oil sludge from the HEUI pressure regulator valve on an annual basis. Your thoughts on this? If it is a good idea, would you be willing to post a video showing us how to do it? Thanks! Love your videos!

[@AdeptApe]

+Craig P I haven't heard this one before. I've heard of a top end oil change, but not cleaning the HEUI pump out. I don't think it would do anything and the pump usually is clean, unless it failed.

[@3pRanchTx]

Ok, thank you!

[@billwade7628]

Craig P 145

[@mdbadalmiah6808]

Thank you sir

[@QRS365]

at 4:53 head appears to be cracked???

[@Pawinterservices]

I have a 2000 F750 with 3126, truck recently started to lose power after 30 minutes of use and reduce to 10mph with CEL. Changed high pressure oil sensor, still no luck, mechanic says high pressure oil pump should be changed, seem like a logical next step? I should mention shutting truck off and restarting clears CEL and problem goes away for 5-15 minutes until it loses power again, seems to happen at lower speeds not highway cruising. Thanks

[@AdeptApe]

+PA Winter Services Before you start changing parts, what is the check engine light? If you have injection actuation pressure faults it might be the pump, but it could also be leaking injector seals.

[@darrelldoward8761]

Adept Ape t

[@gilgil5351]

Hi there, i really hope you could help me troubleshoot my 3126. It started by being harder to start once hot, then again it was hot and didn t start a all sometimes run for a few seconds very rough. Now no start and again try s to start like making some effort thats it just like a gas one with fuel pump problem. Do you think it could be fuel pump on this one too? On it it say s reman. Its the round top one. Strange thing is the line runs strait from the tank to the pump without a filter. Its in a freight fl 60. Thanks in advance.

[@tylermott6563]

Did you ever get it figured out? I have a 3126 in a freight FL60. I suspect bad HEUI pump. Code 164-11 according to cat et. Haven’t done any further troubleshooting yet.

[@gilgil5351]

@@tylermott6563 Hi there, yes i did! Like i said there was no inline filter for i dont know what reason... It was a little piece of plastic like an old straw or something like it that found its way all the way up to the fuel pump line connection. Just pulled it out, put an inline filter and its running perfect since then.

[@michaildziuma9502]

I have 3126 just changed Heui pump truck will start now but it will cut off in 2/3 min Need help please

[@MarkJohnson-oo3dx]

3116 fuel pump does it have to be timing

[@johnstoker1944]

If you do this repair, is it necessary to change the injectors too?

[@dieseltechnician6227]

does the older version heui pump on a cat 3126 require timing before reinstalling or is it the same no timing requirement as the one you installed in this video?

[@AdeptApe]

It isn't timed, you can install it at any point in engine rotation.

[@cumminstech1986]

great videos,have you ever seen a cat 3126 in a 1999 chevy c6500 tach won't work,cat et shows engine rpm but the tach in the dash doesn't,no faults in ecm.I also have a 2003 ford f650 witha 3126 that cat et will not communicate with the ecm,engine will run but et will not communicate through the 9 pin in the cab,i don't have a diagram for the 9 pin in the cab to the cat ecm.

[@AdeptApe]

Well those GMC trucks I've worked on always have dash issues, usually it's in the dash or the GMC wiring. For the ECM not communicating, I've seen that be the ECM or it could also be the wiring. You'll want to put a jumpout harness on it and see if you can communicate then, that'll tell you whether you have a wiring problem or the ECM.

[@cumminstech1986]

thanks

[@QuantumRift]

This is great! Man, your videos are great. The HPOP on my 3126 diesel has a corroded case...I'll be into that job sooner or later. "Adept", my question is this: Is it possible to find JUST the metal DOME for my 1996 3126 HPOP? I knocked off the rust and wire brushed it, and hit it with some Rusteoleum Rust Restore paint, but I'm thinking sooner or later that's gotta be replaced.....I can't see to find just that part.... the "DOME" for the 96 3126 HPOP.

[@AdeptApe]

+QuantumRift I've never heard of changing just the dome on the HEUI pumps. If you wanted to the best bet would be a junkyard, but Cats usually get sold as an engine. Cat doesn't sell just that part though.

[@miftachularifin7751]

Hi Adept, can you explain the difference between C7 and C9 injectors? and can the c9 injector be used in a c7 engine?

[@geegrim5129]

I have a 3126E in a 2004 motorhome. The HEUI pump looks exactly like the one you refer to as on a C7 engine. Is the 3126E similar to the C7 injection system? I know it's the last motor design before they went to the C7.

[@AdeptApe]

+Gee Grim Yes on some of the latest model 3126 engines they had a C7 style HEUI pump. They should still have the square injectors though and the HEUI systems are the same on both engines.

[@geegrim5129]

I've watched a few of your videos, they're very informative. Thanks for the info.

[@honeymantony]

I’d like to test my huei pump-pressure at the head. Where would I find the test port?

[@joseph123456]

Pull the hpop pressure sensor and plumb a gauge in there

[@azedinehamid8530]

should we fill up the heui pump with engine oil after remounting or priming itself

[@amondaka5784]

Hi I would like to find out on my C7 cat engine am having a diesel knock even if after I had changed the supply pump and the Huel pump

[@edwardmandel6340]

Did you find out why yet

[@haleymatson8794]

I replaced the entire top of the engine. On a 2004 c7 cat engine Valves etc. Im getting power to the cab but not too the starter. Replaced injetors o rings. But it wont turn over what could it be

[@AdeptApe]

+Haley Matson Did you suck the oil out of the cylinders after you pulled the injectors?

[@skwlogistics3698]

great videos, keep up the good work. I have a c15acert bxs, does the overhead videos apply to that engine and the injector replacement the same? thanks

[@AdeptApe]

The 3406/C15 injector video applies to your engine. The overhead adjustment one will show you how to adjust the intake and exhaust valves only, not the Jake's, IVAs, or injector height, but I'm going to be making a C15 specific video the next time I do one at work, so hopefully soon. Thanks for commenting.

[@ThePeterbiltrucker]

Adept Ape how about a power steering pump removeal install