04 LB7 Injector Cups?

[TDmkr496]

I believe I have a leaky injector cup, can anyone offer any suggestions as to how to diagnose which one is leaking? I have also heard of people using red loctite around the base (not the Orings). Any suggestions are greatly appreciated!!

 

[juddski88]

I would use green loctite (high temp bearing retainer) and properly heat cycle

 

[WolfLMM]

Green loctite.

 

[TDmkr496]

Ok, whats a proper heat cycle? lol Also, what should I put around the O rings, just regular Oring lube?

 

[TDmkr496]

Anyone?

 

[Dmax87]

You can lube the oring with Vaseline or I've used a very light coat of oil. As far as heat cycle I dunno but I've had good luck with sealing it and allowing it to set up. In other words don't go firing it up 2hrs after you installed the cup, if at all possible start it the next day this may not be the way for everyone but it works for me. Also as far as finding which cup is gonna be hard to find. Why do you think you have a lifted cup, not to rain on your parade but I hear more of head gasket failures than I do cups lifting unless you're pushing some serious power.

 

[WolfLMM]

Two of my cups were lifted. Pushing about 600hp. Let loctite set up. I'm not sure what he meant on heat cycling.... The cups are buried so deep in the motor that would be a major pita to heat cycle those. Just let the loctite cure.

 

[TDmkr496]

I did injectors on it last year and pulling one of them out the cup came with the injector. Not knowing it would cause a leak I put it back in the head, so I'm guessing that may be part of it. How do I diagnose a head gasket leak? My plan was to pull the glow plugs and see if water blows out while cranking. Any thoughts on this??

 

[zf>allison]

I did injectors on it last year and pulling one of them out the cup came with the injector. Not knowing it would cause a leak I put it back in the head, so I'm guessing that may be part of it. How do I diagnose a head gasket leak? My plan was to pull the glow plugs and see if water blows out while cranking. Any thoughts on this??

I did the same thing and it push the day I put my exergy cp3 on. I used red fine so far.

 

[TDmkr496]

How do I check for a blown head gasket?

 

[ecc_33]

Does the overflow tube have black looking soot in the coolant? Is the upper radiator hose hard? If you have coolant coming out the glow plug holes after glow plugs are removed chances are its a cup that's lifted. All the head gaskets I've seen blown were pressurizing the coolant overflow tank and had black soot in the bottle.

 

[TDmkr496]

I have not seen any soot in the overflow tank, I'll pull the glow plugs and look for coolant there. How can I spin the motor over without the injectors firing, can I unplug the crank position sensor?

 

[jlawles2]

unplug the bail connectors on top of the engine. Engine will turn over with key. All of the injector signals run through the bail connectors.

Was originally posted by Pat about how to keep the truck from starting when doing a compression test. Thanks Pat for the useful information.

 

[ecc_33]

Injector fuse under the hood. Pressurize the cooling system and let it set with the glow plugs out of the heads.

 

[TDmkr496]

Put it on my lift Sunday and pulled the glow plugs after driving the truck for a bit, last night I spun the motor over and it blew coolant out of the #6 cylinder. So I'll start to tear it apart tonight and see what the cup looks like.

 

[TDmkr496]

I pulled the cup out of the #6 cylinder and replaced it, sealed it with the green loctite and put it back together. Got it running last night and so far no issues. Thanks for the help guys!!