Hi David, I've just pulled mine over the weekend after taking the truck to S&S Diesels in Bishops Waltham near Southampton, where they diagnosed a slight misfire. I'm going there tomorrow with my injectors. They quoted me £2.50 each to test them and £35 to £75 to service them depending on what's needed. Very helpful and knowledgeable. Just ordered the lower copper sealing washers from Toy at £25 or so for all 6. There are O rings, but to be honest, all they do is keep the crap and moisture from falling down around the injector and any O ring that'll take the temperature will do, especially as Toy want another £25 or so for them (no thanks). They are 2.5mm section x 18mm Internal diameter. Mine are crispy and will need replacing!!
Injectors look like this:
They 'pull' out but I needed to use a pry bar like this:
And some grips to turn them round once loosened. They take a bit of shifting but that pry bar was the tool under the connection and against the adjacent cylinder head bolt with a few hits with the heal of my hand.
Before undoing anything, clean the area around the fuel nut scrupulously and don't let the tiniest bit of dirt get in anything where the fuel goes in. I cut some clean plastic bags into squares and slipped an o ring over the ends of the pipes like this:
S&S gave me some caps like you see on the injector but they were a tad big for the pipes. I think 8mm should be the right size to slip on. I cannot emphasise enough how clean you need to be around these connections.
When I pulled the injectors, most left the washer behind but one didn't and it looks like this:
I decided to replace the copper washers but they were in pretty good nick. I also numbered the injectors just in case. I also undid and removed the pipe clamps that hold the injection pipes just to give more wiggle room on the pipes.
I'll do an update tomorrow when I've been to see them.