Detroit 8.2 fuel pincher

[New Englander]

Yeah, I know it's a POS but it's simply a yard truck. It's also the best starting diesel I've ever seen.

Anyway, it's probably some sort of injector seal and I wonder if anyone has ever tackled it without all the special tools that are apparently needed? I don't want it to be perfect, just stop the diesel getting into the oil. 

[dale560]

Get some dye and mix it with fuel. Run truck for a bit to warm up then check with uv light. I don’t work on 8.2 very much but they have the gear pump , then the injectors and cross tubes to leak. On Cummins n14 and the other big engines when you have a fuel in oil it is best to check with dye. I mix up a separate container with a couple gals of fuel then run it with that . Usually most trucks have the fancy fuel water separator you can unhook main tank and Jerry rig a hose into container. Probably should warm it up good before switching to dye fuel. As far as setting them I think you can do it with a caliper with tail extended to right depth. They use a dial indicator on the 8.2. Back before the internet and everything available on line I set a lot of 2 cycle Detroit and 3406 e injectors with a measuring tool with tail extended to correct dimension. 

[Mudfly]

I was waiting if anyone else commented on this, since I have zero first hand knowledge. I will say that the YouTube channel Farmcraft101 just redid his injectors on a fuel pincher for the exact same reason (fuel in the oil).  He also changed the fuel pump, reset the governor, and set the output on the injectors.  He was able to source the tools, but discussed what would be needed to work on it without the specific tools.  
it looked like a PITA to me, but could see how it would be worth it vs trying to repower a truck with a different engine.

 

[Mudfly]

 

[New Englander]

So I looked closely at what it would take and weighed the effort required v the amount of time I use the truck and just changed the oil. It's a bucket truck and the engine mostly idles for hours doing whatever chore I need - tree work, siding, roofing, etc. Simple things like adjusting the TV antenna. Yes, still get local stations over the air and stream Netflix, Prime, and Britbox for entertainment. Right now I'm doing some siding work. I can't imagine going back to staging and ladders. 

Detroit's first shot at a 4 stroke engine and they got a lot right and sadly, some big things wrong. I think we bashed it here years ago. It's still getting fuel in the oil.😁. It's really too bad. Truck will sit for months and start right up even when below freezing.

[from H to 80]

I remember when our fuel delivery man got a brand new fuel pincher diesel, he was as proud as a Peacock, for about two months. The coop purchased it from a local dealership with no diesel experience at all,they towed it in with their wrecker,and didn't pull an axle,and it locked up the rear end. It spent as much time in the shop as it did hauling fuel and after a few years it got parked.

[dale560]

Again I can’t stress enough to run dye in it to see what is actually leaking. About 15 years ago my good friend bought a really nice Volvo Vnl with a n14 Cummins. It belonged to a guy local to him that hauled grain. It was putting fuel in the oil. The owner before had tried to have it fixed. Someone had replaced the pt pump and some fuel injectors along the way. The original owner was fed up with the fuel in oil so sold the truck at the time to my buddy for 5000 about a third of its value then. I told him I will get it figured out for him so bought some fuel safe dye and up light. 2  of the reman injectors was just pouring fuel out of the top plunger area. He tried to find cheap rebuilt but we ended up after a couple months putting in two Cummins rebuilt injectors and truck has been perfect since then. I also rolled bearings in for him afterwords but there is more to that story. 
But again if you want to diagnose and just fix the leak run dye through it.

[New Englander]

On 9/9/2026 at 8:12 AM, dale560 said:

Again I can’t stress enough to run dye in it to see what is actually leaking. About 15 years ago my good friend bought a really nice Volvo Vnl with a n14 Cummins. It belonged to a guy local to him that hauled grain. It was putting fuel in the oil. The owner before had tried to have it fixed. Someone had replaced the pt pump and some fuel injectors along the way. The original owner was fed up with the fuel in oil so sold the truck at the time to my buddy for 5000 about a third of its value then. I told him I will get it figured out for him so bought some fuel safe dye and up light. 2  of the reman injectors was just pouring fuel out of the top plunger area. He tried to find cheap rebuilt but we ended up after a couple months putting in two Cummins rebuilt injectors and truck has been perfect since then. I also rolled bearings in for him afterwords but there is more to that story. 
But again if you want to diagnose and just fix the leak run dye through it.

I watched the whole video and it was very informative and step by step including the mistakes and corrections. If this was a road truck I would do exactly as he did. Interestingly it seems that there were no leaking o rings but the injectors were dribbling badly and one was completely dead. He found a rebuilder who did them for $85: each, which I thought was a bargain. Still too much time and effort for my truck. 

[Big Bud guy]

On 9/8/2026 at 8:41 AM, New Englander said:

Yeah, I know it's a POS but it's simply a yard truck. It's also the best starting diesel I've ever seen.

 

That’s interesting.  I’d say our fuel pincher is the worst or one of the worst starting diesel engines we have.

[Binderoid]

On 9/9/2026 at 7:33 AM, from H to 80 said:

I remember when our fuel delivery man got a brand new fuel pincher diesel, he was as proud as a Peacock, for about two months. The coop purchased it from a local dealership with no diesel experience at all,they towed it in with their wrecker,and didn't pull an axle,and it locked up the rear end. It spent as much time in the shop as it did hauling fuel and after a few years it got parked.

Why would  not pulling an axle  would  make the rear end lock up? 

[dale560]

59 minutes ago, Binderoid said:

Why would  not pulling an axle  would  make the rear end lock up? 

Old wife’s tale. Older semis if you pulled a long way with driveshaft hooked up might have trouble with auxiliary section bearings. Like I said might be a problem. 

[brahamfireman]

1 hour ago, Binderoid said:

Why would  not pulling an axle  would  make the rear end lock up? 

Guessing they left the driveshaft hooked up and output shaft locked up from lack of lube.

[dale560]

Being it’s a 8.2 engine it would be early 80s to mid 80 gm truck. Not many of the cheaper trucks back then had oil coolers for the transmission. Higher dollar over the road trucks yes.if they had a cooler they used a pump to circulate oil.Being it was a 8.2 highly doubt it had a pump in trans. While not getting the full lubrication there still will be some oil splashing with output shaft turning. With drive shaft attached. The one rare possibility is if truck was low on air pressure and somebody shifted the high,low splitter and it didn’t have enough air to shift into gear and popped to no engage neutral spot on range. Like I said more of an old wife’s tale than possibility. Now with it being said in odd instances it can cause issues on a select few trucks. But towing a truck a few miles isn’t going to ruin the old ones.

[supermechanic]

3 hours ago, Binderoid said:

Why would  not pulling an axle  would  make the rear end lock up? 

 

 Did some roadside recovery on class 8 trucks years ago.

Some transmissions rely on pumps to keep the lube oil flowing.

 If the particular transmission in the truck you are towing does not have a pump on the output shaft, extended towing may cause overheating from lack of lubrication.

 Damage may follow.

 This is likely where the idea that the rear would lock comes from.

 It was a written procedure that any flat towing was done with the axles pulled.

Tow truck driver was not expected to know which transmissions contained both a front and a rear pump, hence, all were treated the same.

 This was in my shop, your experiences may vary.

[dale560]

Think of this though when you pull axles now you have no oil in wheel bearings. Unless you had caps and a fill plug for every axle bolt pattern with you. 
A lot of this comes from when people see long transit truck piggy back setups. There they pull axles on the rear and cap it. Generally the guys do this for a business and have the setups needed for trucks they move. Including lights and brake connectors.
most big rig towing services probably do this on long haul stuff but short local 100 mile tow hook it and go. Now if it is a John Deere truck you just put it in tow position and go.

[dale560]

Another thing to mention with towing with driveshaft spinning. Is did they cover turbo also? Another one of those towing might happen but probably didn’t.