Injector Installation Tip

[JMK]

Today I had to reinstall rebuilt injectors, but I had a problem. One of the injectors had been previously installed incorrectly and there was a lot of carbon build up on the bottom threads. The upper copper gasket was seized right into the seat, and the injector would not thread properly without a lot of force.

I borrowed a seal pick tool from one of the mechanics at work but as the upper gasket was seized in so tight it did not work. I contemplated running a 20mm tap through the threads to clean them up, but was nervous about the metal shavings going into the cylinder so I forgot that idea. Later at work when I was cleaning my issue firearm, a 12 guage Remington 870 Wingmaster, the bronze brush appeared to look like a perfect size. So I grabbed it, and a .308 brush, some patches, and a cleaning rod. When I got home I compared the fuel injectors to the brushes and the match was perfect. I shot some WD40 into the injector hole and reamed it with the 12 guage brush, then reamed the smaller lower opening in the head with the .308 brush. Eventually the threads were nice and clean and I could see the copper of the gaskets. (Use WD40 to 'flush' the holes before you thread).

Now I was able to thread the injector into the head using finger pressure all the way to the end. It seemed to me that for cleaning the injector ports and threads the bronze brushes were the 'cat's ass', and not even our mechanics had a tool that could do this job, but it seems obvious that you should clean all the seats and threads of the carbon deposits before you thread new injectors in.

So for those of you that are hunters or peace officers you'll have the required kit already, or if you know hunters that own a 12 guage shotgun and a .308 (or a .303) rifle (a .357 or .38 would probably also work), borrow their cleaning kit before you put your injectors back in. For those that don't, go to you local gun shop and buy a couple of Phosphor Bronze brushes for a few bucks, and I'd also recommend a 8-32 threaded rod for them for a few bucks more.

[sahdot]

Nice tip! Thanks for posting.

-jim