Sidewinder

I just finished adjusting my valves (piece of cake) and I replaced the gaskets and o-rings on the rocker cover to fix the oil leaks. After this I went to the coin-op and washed down the engine. I can now see that the rocker covers no longer leak but it looks like 5 of the 6 injectors are leaking from around the base near the head, not from the lines. Two of them are pretty bad leaks.

I removed all of the lines and tried to tighten the large 15/16" nut on the bottom of the injectors with a deep socket. Is this the right place to tighten to get rid of these leaks?

Also 2 of the 5 leaking ones seem to turn the entire injector when I try to tighten them, is this normal?? If I leave them like this I can't get the return line back on.

I also tried to remove the 15/16" nut from #6 injector (easiest to get to) but it seem to be incredibly tight. It does turn a little but as I said it is the whole injector that is turning and not just the nut. How hard do I need to pull on the wrench to loosen this nut??

HELP!!

How do I stop these leaks? or do I need to completely remove/replace the injectors?? If I do remove them what do I need to reinstall them?? The truck is now stuck halfway inside the garage so I guess I will have to reinstall everything to get it back outside.

Thanks for any replies!!

Sidewinder

It's getting worse!

I put everything back together and now I have a MAJOR leak at #3 return line fitting. I tried tightening it but I don't want to strip it. What else can go wrong.

At least the valve adjustment went OK!

dsljunkie

Try replacing all the copper fittings (on the return line and on the bottom of the injectors) THis will require pulling the injectors but thats no big deal. Make sure you clean the injector slots (in the head) good before you stick the injectors back in.
Good luck
Scott

infidel

It's sort of strange that the whole injector turns, every one I've seen has a locator that keeps them from rotating. If you replace the copper injector washers they should be the same thickness or the injection position into the cylinder will be off. There are several different thicknesses for different injectors. Since you are going to have to pull the injectors to replace the washers and go to a diesel pump shop for them I'd take the injectors in for testing, it's cheap. While there get a injector bore cleaning brush and washers for the return lines also.
Never bend the lines out of the way to pull injectors, remove them entirely. They are very hard steel and will break if bent.

If your injectors are leaking as bad as you say fixing it up should make your truck run a lot better.

Sidewinder

OK,

I guess they will have to come out. How tight should the nuts be. I tried pulling really hard on the wrench and like I said it seems like the entire injector turns, not alot maybe a 1/16 of a turn then gets really tight. I can then turn it 1/16 of a turn back in the other direction. Thats all of the movement I can get.

Is the 15/16" nut on the bottom the thing to undo to get the injectors out??

I have a Cummins shop near me. Will they sell me the copper washers and will they test the injectors for me??

berner

There's a ball on the injector that fits into a slot in the head that keeps it from turning. It sounds like the injector and the retaining nut have seized together. You don't want the injector turning with the nut when you loosen the nut or you'll either shear the ball off or destroy the slot in the head.

Soak everything down really good with some penetrating oil. There's a rubber sealing washer that goes in the top of the retaining nut. Try to pull the washer out so the penetrating oil can get down. The nuts are only supposed to be torqued to 44 ft-lbs. If you can get a boxend wrench on the retaining nuts, you may be able to hold the top of the injectors with an open end wrench so they don't turn.

When you put it back together, take some 400 wet/dry sandpaper and clean the sealing surfaces on the return line and the injectors really good. Put some Never-Sieze on the injectors and retaining nuts.

Sidewinder

Well I got it back together without the return line leaking but now the injectors are leaking worse from around the nut. The reason the return line was leaking was that the injector was turned slightly and the line was not sitting flat on the injector.

I guess I will go and buy a new set of copper washers for the return lines and the injectors and remove them and replace the washers, when I have time.

I just hope I can get the retaining nuts off without screwing up the injectors, they are really tight. I don't know if penetrating lube would help as there is already diesel all over them and I assume that with the diesel fuel and the heating/cooling cycles they should have all of the lube they can get.

Thanks for the replies!!

Sidewinder

One more question,

I am going to try to remove the injectors this weekend. I got the injector copper washers, the rubber seals and the return line copper washers all from Cummins.

I was talking to a "diesel expert" and he said that the locators on the injectors are spring loaded like the ***** on a socket wrench and that it is OK if they (injectors) turn when undoing the big retaining nut. Is this true??

Like I said they seem to be verrry tight to the nuts and I don't want to break anything getting this apart. I want new injectors but not just yet!!!

infidel

Easy way to get your 12 valve injectors out. Remove the fuel lines from both ends. Do not bend them. Remove the nuts. Cut or grind a 1/2'' PVC coupling to 1-3/8'' long. 3/4'' steel pipe, conduit etc. will also work. Slip it over the injector and use one of you wheel lug nuts (fits where the fuel line went) to tighten down on the pipe. It won't take much force at all.

firestorm

Check around for a 'shop manual on CD' for your truck. I got one, but it's for the '01 24valve. Cost me $15 from ebay.

berner

Can't say for sure but I tried to compress the ball with pliers when I changed my injectors and couldn't move it. My CD manual warns against letting the injector turn in the head.

Sidewinder

Thanks for the help! I am going to try this tomorrow. I will remove all of the lines first and TRY to stop the injectors from turning. It didn't make sence to me to put in a locating ball that can move. Once I get the nut off I will try the pipe/lugnut removal procedure.

Update pending.

Smkndzl

the ball on the injectors do not move at all , when you remove the injectors make sure you get the coppers out with them , if not , you will need to go in the injector hole and remove them , also use anti sieze on the new coppers when you install them on the injectors so that they will not fall off during installation , good idea to have them pop tested at the Cummins shop.

Sidewinder

OK,

I got the first one out. Wasn't so bad, but I started with an easy one. Everything looks good, no carbon on the tip.

One more question though. What goes on the bottom of the injector? Is it only a copper washer? There is a small groove in there is that just for clearence? I read on another post that there is an O-ring somewhere. I don't see one. All the parts I have to replace is the washers on the injector tip, the double washers on the return line and the rubber seals between the injector and nut. Is this correct? What does the rubber "seal" do? It looks like it would only keep dirt of the threads.

I will check back when/if I get the other 5 out.

infidel

That's exactly right.
Sounds like you've got a good handle on it.
Good luck on the leaks!