I disagree with a lot of this. ^^^

These are not torque to yield bolts. They do not need to be replaced as a matter of course.

‘Dry’ is the correct method for torquing these bolts.

Red ‘high strength’ thread locker is wrong.

Absolutely ‘seat’ the injectors with a rubber mallet before torquing the bolts. Failure to do this can allow you to reach the torque spec and cause an incomplete seal at the copper washer. This isn’t a King Kong blow, we are just tapping them down until the sound changes when they bottom out.

NEVER use anything but Motorcraft injector o-rings/washers. The aftermarket sucks and are nearly guaranteed to fail prematurely.

Whatever I said previously in this old thread is based on experience changing dozens and dozens of sets of 7.3 injectors over nearly 20yrs with zero problems yet. AFAIK, I follow the Ford/International guidelines for installing these injectors, but I’ll be honest - I have not read any directions for a long, long time.

 

Agreed %100

 

I'll come in and say that unless you dry out the female threads in the cylinder head for the hold down bolts, and soak the bolts in brake clean, you won't be torquing it "dry". And I'm on the side of lubing the threads, but absolutely against using red locktight in this application. It simply won't let go unless you heat the surrounding area to some outragious temperature in the 450f range. Use blue, or if you want high strength, use orange. For the record, I don't torque "dry" or use any sort of locktight. And then use an inch-pound torque wrench.
And I'm thinking that using a rubber mallet won't "sledgehammer" the injector home. I would be more worried about breaking the solinoid on top of the assembly if I hit it hard enough to distort the sealing washer on the bottom. Sometimes the locations of the rear injectors don't offer a good position to put any body weight on it and push it down where it belongs and a gentle nudge with a rubber mallet will accomplish the task just fine.

 

Can't speak for injector bolts but when stretching rod bolts different lubes will give different torque values for the same amount of bolt stretch.

 

Totally different type of bolt.

 

EVERYTHING YOU SAID IS WRONG...apparently you never worked on many engines...NO bolt should ever go on dry...you will just be back in there and you will see on re-torque that, even though tight, they will need brought up to spec...been there, done that years ago...We all know mechanics...fixing engineers calculated mistakes!

RED High Temp, not "high strength"

NEVER SET INJECTORS BY HAMMER...EVER EVER EVER....They are crush washers for a reason....If body strength won't do it with a small pop, something is wrong. I recommend Kimball Midwest O-Ring lube.





Never said they are torque to yield...they are known to stretch, just like the head bolts...and the water pump bolts...and the oil cooler caps bolts....valve cover bolts are the some of the few that are decent...if you've had one break, you are not alone...or if your engine care is unknown and they've been torqued a few times, you may get a few in before SNAP...on the up side they come out rather easily.

So yeah...drove for 17 years, wrenched auto trans and hot rodding for 7, last 7 wrenching and towing big trucks, last 2 managing a shop...



I'll go with my experience and do what I know works.....Take or leave it, makes no difference to me.

If you do not use locktite, its just a preference for me. Hi Temp will lock em in and also prevent rusting of the bolts to the head, especially handy on exhaust and up pipe bolts. Anything aluminum gets the Lock Tite Lube...

If its good enough for CAT engines, its good enough for all the other big truck engines, especially PACCAR, all their outer engine bolts get that powder build up that makes em break, similar to the 7.3s AC compressor...many of those broke no matter what you did...

THE BOLT LUBE???

LocTite

LB 8012

You're welcome...

Have a great day everyone and God bless y'all

 

All bolts will stretch and you can change torque readings just by lubing under the head of the bolt. Whether these bolts are classified as torque to yield doesn't matter, no lube and you're just testing the friction of the threads and under the head of the bolt.

 

Rather than reopening old threads I thought I'd put my thought in here on the hot retorque.

When you seat the injector, and torque it. You're 'forming' that copper. When you form copper it work hardens it.

If you work with copper you know that you need to anneal copper again to continue forming it. It doesn't take a huge amount of heat to anneal copper 400-500deg for a few mins will usually do it (or higher temps up to 1000deg for a few sec).

IF, the seating surfaces of the cup and injector are imperfect, that extra annealing may allow you to further seat in and seal the injector to the cup.

Again, this is just my theory. I'm not an engineer and didn't stay at a holiday in last night.. lol

 

Listen sweetheart, I’ve installed a few hundred 7.3 injectors by now. You can choose a different path, but you’d be foolish to say I’m wrong.

I have literally never had a truck come back with an injector install issue. Dozens and dozens of trucks over 20yrs have not had a problem after I followed the Ford/International method.

This forum is full of belts and suspenders folks. The OG culture was to out do one another with details.

Your way is fine for you. I promise I’ve worked on worse and cursed idiots regularly specifically for misusing thread locker products.

Meanwhile, just my personal truck has seen nearly 400k miles and a few injector changes. I even went back under the VC’s out of curiosity when this whole ‘hot re-torque’ silliness began. Ford says if they’re still over 50 in/lbs, they’re good. In my case, they were over 50 and stayed that way another 100k miles last time. Unfortunately, I’ve had to go back and replace lots of crappy injectors built by high-volume vendors. This also gives me the opportunity to check my work and verify no injector has ever gotten loose or compromised a copper washer.

Good luck and good luck to the poor guys that have to remove your ‘high temp’ thread locker bolts or the over tightened ‘lubed’ bolts you installed.

 

Ugh. Dang mobile stuff.

 

I've been waiting all day for this.