Budget Cummins 12V Injector Rebuild & Pop Pressure Test

Here's a rundown of how I was able to rebuild the mechanical injectors at my own shop. I came close to just buying new injectors, or having a shop pop test my old ones, but after some research I was surprised to find pressure testers so cheap! Results were about as expected, tester worked OK, but started leaking and will need some TLC before another round of injectors.
For a good video that goes over the internal injector parts in more detail, check out Deboss garage. The injectors are fairly simple, just pay attention to the orientation of all the pieces when you take one apart, they really only got together one way if you line up all the holes.
I've seen the testers as cheap as $78 on ebay, but the foam padding that came in the box wasn't quite the best, so beware if it's coming all the way from china!
Also, I bought the OEM Bosch injector rebuild parts, but turns out that the parts were made in India... Not sure where the originals were made, but not sure if I'd trust these to last another 300,000 miles? Time will tell I guess.

[@ziptiesnbiasplies]

Great Vidya bud.

[@toocheaptosmoke]

Thanks man!!

[@pl9105]

Didnt think i'd see you here man

[@Mr69barracuda]

I have one and use the knob to both test "Exact presures" and "Bleed off" for removal. Testing run the pump presur up as high as you can (one pop) and repressure with knob Half way out or a lil more. Then turn the knob in you can see "Exact" pop pressure without the needle bounce. Then when you back the knob out.. it releases pressure for injector removal.

[@crapalator]

thanks toocheap.iv always wondered how a diesel worked.

[@jeremyb2907]

Pennsylvania resident like me the inspection sticker gave it away

[@cesarjorgemurillobarientos1813]

very good

[@RealMrBen]

Very entertaing video bud and informative

[@toocheaptosmoke]

Thanks man!

[@alanair7019]

do you have to prime those pop testers? if so can you do a video?

[@kubaSWAT]

Whats the handle/valve for?? how to use it thanks

[@JoshKilen]

very nice job. may I ask why did you decide to use atf instead of diesel?

[@toocheaptosmoke]

Heard about other people using ATF because of it having some lubricity.

[@johnfitzpatrick37]

Thanks...clear and helpful. Question, please, re LEAKING Shut-Off Valve you discuss at 9:35-10:55. Had exact same problem on day one! If you fixed that, HOW, please?

[@toocheaptosmoke]

Unfortunately I have not messed with it much since then. Has to be a simple o ring or seal in there though?

[@nathanwest2304]

@@toocheaptosmoke I'd recommend to just factory delete that thing put a plug in there or cut it off and weld it shut I went for a tester without that valve cuz the amazon reviews guided me in that direction even if you can get it to seal, it's very difficult to actually get a moving shaft tight, especially at these pressures edit also it was cheaper without the valve

[@loveyourself1759]

do a teardown of the pop tester I found a lot of crap in mine, especially the one way valve inside was caked with metal shavings and grinding dust but you need to mount it on a solid surface cuz all the threads are tight af

[@toocheaptosmoke]

I'll probably wait until I need the tester again, then be forced to rebuild it, haha.

[@jcw74801]

Where did you get your parts and shims? I can't find anything for 12-valve injectors.

[@toocheaptosmoke]

Think it was someone on ebay selling the kit.

[@isaacbittner3730]

Powerdrivendiesel has them

[@hughjarse4627]

I’m a fuel injection technician. Not a a bad effort. The knobs on pop testers are to lock the gauge off usually or to adjust flow. Yours looks like a lock off knob.

[@toocheaptosmoke]

Good to know. The directions that came with it were, well, lacking... lol

[@kubaSWAT]

can you please explain how to use this knob?

[@_CSD_]

Hi, where did you get the shims from and what thickness are they avaliable in or is there an "all rounder" size? Thanks

[@toocheaptosmoke]

There's a kit on ebay, they come in a couple standard thicknesses, but you can mix and match multiple shims to get the desired thickness.

[@_CSD_]

@@toocheaptosmoke thanks, friend. Be well.

[@malcolmyoung7866]

Just bought one of the myself.. 3 spelling mistakes in the instructions.. disappointly..😏 anyhoo… the screw in handle which was leaking… you can use that to do a ‘leak test’ so what you do is pump up the pressure but stop before the ‘pop’ pressure and screw that handle in and leave it.. if fuel leaks out.. the injector needs sorting etc. At least that’s how it meant to be.

[@toocheaptosmoke]

Good to know!

[@toocheaptosmoke]

Good to know!

[@RichinZhills]

So maybe that turn nob is to simply bleed off the remaining pressure so you can safely remove the injector. You tighten it up fully, test it, and then untwist it to release. My guess is that you'll still have up to 3k of pressure left after it pops, so you don't want to unscrew your injector with the fuel still pressurized.

[@toocheaptosmoke]

True, that might be the right way.

[@Mr69barracuda]

I have one and use the knob to both test "Exact presures" and "Bleed off" for removal. Testing run the pump presur up as high as you can (one pop) and repressure with knob Half way out or a lil more. Then turn the knob in you can see "Exact" pop pressure without the needle bounce. Then when you back the knob out.. it releases pressure for injector removal.

[@toddhess9439]

How did you get your tester to hold at 3000 psi? I hooked mine up and every injector i pump them up and mine are bigger and all pop around 4000-4200 psi but after they pop the pressure slowly goes down. Even if i pump it up right to before they pop the pressure still goes down on the gauge slowly... and non of the injector tips seem to drip or leak. Thanks

[@toocheaptosmoke]

I would leave the knob about a turn or two out, then after you've pumped up some pressure close it the whole way and see if that works.

[@Jethrosgarage]

I have a genuine old Bosch tester, but the plastic reservoir disintegrated after years in my 100* in the summer garage.

[@toocheaptosmoke]

Nice, bet that cost a pretty penny when new!

[@ethanpeterson3828]

How do u get the pressure to rise or drop if it is way off

[@toocheaptosmoke]

On the injector? shim adjustments or new spring

[@gopalakrishnadoddi4869]

how to convert crdi injector to manual injector please give me the link or video

[@bloodswettears234]

Funny👍

[@riverguy988]

A larger than stock injector can actually improve fuel economy.

[@davekimbler2308]

Well ...... one more video down and perhaps one more Ram back on the road to hit some deer ! Lol. I heard with you Canadians it’s like a badge of honor to hit the most deer ! One guy told me after he hit a moose that 10 people asked if they could harvest the animal and he hadn’t even gotten out of his truck yet ! Lol

[@toocheaptosmoke]

Haha, I might spend a bit of time up in Canadia, but I'm based in 'murica! Lol. Lot of deer hit here though too...

[@davekimbler2308]

toocheaptosmoke were is that ? I’m not familiar with that town ! Lol. By the way you talk I thought you a Canadian ! Lol

[@anthonyrybczynski5420]

Ya, the trucks severely damaged every time though. We get lots at our shop. Nothing 8000 to 15000$ won't fix. Lots of deer around here.

[@davidroberts2404]

Those are nozzles not injectors

[@EvanWSH]

What are you on about ? He's got injectors with nozzles on them, I dont know how else you figure you'd pop test them

[@dennissmith460]

@@EvanWSH He's right. Those are just fuel nozzles. There's a difference.

[@EvanWSH]

@dennis smith uh no he isn't right, the entire unit is an injector, the piece sticking out passed the copper sealing washer on the bottom is the nozzle. If you go to 9:25 you can see the new nozzles swapped in.

[@dennissmith460]

@Evan Ward No, the entire unit is a fuel nozzle. The part swapped out is just the tip. Pre electronic cat engines use the same system. That nozzle has a tip, spring, and metering plate, which only allows flow in one direction and ensurese the fuel pressure is enough to atomize the fuel. Thus, the pop off pressure. An injector supplies the pressurized fuel. Usually through a plunger assembly. With a fuel nozzle pressure is supplied by the pump. Usually having plungers and a rack to meter the fuel.

[@EvanWSH]

@dennis smith so you're going to argue that the only technical fuel injectors are heui units and anything else including every single common rail injector is not technically an injector and anyone who refers to it as such is wrong.