Installing New Injectors

[MrMarty51]

I have done a massive search and I dont find the information.
Should a person apply anti seize to the threads of the new injectors before screwing them into their bores.
The book says nothing about this.
I do know that lubricated threads is supose to change the torque value when tightening.
Anyone have any thoughts on to use anti seize or to not use it ?

 

[Will L.]

No. They go in dry

 

[SnowDrift]

I used it on the threads when I did mine 15+ years ago and am glad I did, personally. As hard as they twisted coming out, I am not sure what sort of result there would have been if they hadn't been done like that.

I've only done one set, though. Maybe there is a reason do install in a different manner.

 

[MrMarty51]

I know at less than 20,000 miles these injectors came out hard, to unscrew mainly.
Maybe do a diameter/thread count and see what the chart says for that size of a bolt and that thread count for torque and check the difference between lube and dry threads.

 

[Big T]

I have done a massive search and I dont find the information.
Should a person apply anti seize to the threads of the new injectors before screwing them into their bores.
The book says nothing about this.
I do know that lubricated threads is supose to change the torque value when tightening.
Anyone have any thoughts on to use anti seize or to not use it ?

No

 

[Will L.]

If you use anti-seize, you have to understand you will not do the same torque, it will be lower. I am the guy to tell people always use a torque wrench- but honestly in the fleet and on my own stuff for years i tightened until it felt right. On a paying customer where its a one time deal- torque wrench. But the fleets paid me to use MY judgment to alter from factory. If I had a customer ask me to- or if I was in the rust belt- then yes I would add it and guess by feel, knowing less effort will get it tight.

 

[SnowDrift]

I wish I could say I used a torque wrench, but I'm not sure I did - just can't remember. If the instructions from Heath Diesel said to do it, then I'm positive I did so.

It sounds like the torque rating change would be the only reason to not use an anti-sieze compound, though, correct?

Even though my truck doesn't see salt, I still treat it as if it would.

 

[WarWagon]

On a paying customer where its a one time deal- torque wrench.

Pics or it didn't happen!

 

[Will L.]

Here is the thing… why do you want to add it? So that years and years down the road it still gets removed properly. But over tightening will make it much harder to remove years later. So if you are not in an area where rusting is a concern- how little is the gain vs how big is the risk?
200,000 miles later- no anti seize will remain. It will all cook out and go out the tail pipe.

 

[MrMarty51]

Measured the diameter of the threaded portion of the injector, 24mm. The thread pitch is 1.50.
There is no torque spec for that size and pitch that would be even close to the 50 ft. lbs. it tells in the book.
Looking on my torque chart cheat sheets, a 7/16ths 14 pitch thread dry is 50 ft. lbs. of torque. Lube threads cuts it to 30 ft. lbs.
Not going to use anti seize or any other kind of lube on the threads.
The injectors appeared to have been bathed in diesel fuel.
Took them to a clean pan, a little mineral spirits and a new brush for cleaning and washed the fuel from the injectors. Hit them with a good stream of B&P cleaner and letting them dry.
I did read about using some type of sticky substance and dabbing the washer shoulder with that so that the copper sealing washer dont fall off and it appears that the wheel bearing grease I dabbed onto the washer area has stuck and the copper washers still seems secure.
It was through the search that I discovered where another forum member had posted that hint/tip about the copper washers falling off if some preventive measures was not taken.
I cant remember who that person was and I have never seen any posts from him but I do thank Him for posting that information.
And so now, no anti seize, no lube of any kind on the threads of the injectors and fifty foot pounds of torque.
Once the injectors are installed and torqued then it will be the new GP harnesses. Fuel injector pipes will be after that, then the FFM on its pedestal rack then fire this thing up and check to make sure there is no valve cover leaks.

 

[Husker6.5]

@MrMarty51 those torque specs are for clamping force being used as a fastener. The torque spec for an injector is for what will keep it from vibration/heat cycle loosening and allowing combustion to escape WITHOUT that torque on the injector causing enough distortion to the hollow injector to interfere with the internal mechanism's operation via binding, misalignment, etc. 50 lb/ft is that magic torque number.

 

[MrMarty51]

@MrMarty51 those torque specs are for clamping force being used as a fastener. The torque spec for an injector is for what will keep it from vibration/heat cycle loosening and allowing combustion to escape WITHOUT that torque on the injector causing enough distortion to the hollow injector to interfere with the internal mechanism's operation via binding, misalignment, etc. 50 lb/ft is that magic torque number.

Well, that makes perfectly good sense.
And while that lubed thread, 30 ft. lbs. would give it the same clamping force on the gasket, with that thread line involved, and the lesser torque on the injector, that would allow the injector to back out a lot easier.

 

[Big T]

Way over thinking it here. You want it sufficiently tight, but also want the return line nipples lined up with the other injectors. Boom, done!