Sorry for the extra post, but in I've got the truck tore apart. I replaced cups about 2 months ago, everything seemed fine until a long trip pulling the 5er. Had some fuel in the coolant again, not much but it is diffently there. I did a rooking mistake and did not torque the injectors when I put the cups in. Right now I have had the cooling system pressurized to 30 pounds for over 20 minutes and I'm not seeing anything leaching into the cups. I'm not loosing any press either. Could not torquing the injectors have caused some fuel to get in the coolant? I don't want to pull cups again if I don't have too.

 

fuel to coolant is 99% of the time cups. 1 of the other 6 may have started to leak.
to it is best to do a 8 as the work it not much more.

 

But with 25 pounds do pressure on the cooling system shouldn't I be seeing something leaking onto the cups by now?

 

the fuel is at a higher psi then 25, so it might not show if it is a very small leak.

 

I need to back up the bus a bit.

1. 30 PSI is too high. The cooling system is engineered to prevent going over 15 PSI - ever. Going that high with a test could actually cause the issue you're trying to look for.
2. How many cups did you replace, and how many injectors are out of the engine for the test?
3. Is it a sheen on the coolant, or can you see a thick layer of fuel? Remember... there will be remnants of fuel lining the cooling system. How did you rule out oil in your coolant?
4. There is a link in my signature - "New injector cups". Click it.

 

When I replaced the cups a couple of months ago I did all 8.

It is a thick layers of fuel, and it smells like diesel.

I went ahead and pulled all 8 again and put new ones last night. Being really careful to everything real clean. I headed out now to start putting everything back together and hope for the best. Going to wait until this afternoon to start it up to make sure I get a good 12 hours plus cure time.

 

When I did my cups, I took a lot of time and care with each step. I did not want to set myself up for an encore performance, because it's about as much fun as setting my hair on fire and beating it out with a club. I let the goop set for 24 hours (coolant in engine - the sealant is anaerobic), then I pressurized the cooling system to 15 PSI and let it set overnight before I even considered dropping an injector down a hole. I felt very confident I had a good seal before putting things back together and test-firing. After idling the engine for a test, I gave it even more time for the top-side sealant to set (again - the goop is anaerobic and the top needed to be robbed of oxygen). My process took a long time and I drove another vehicle while I waited for Stinky to properly heal, but I did it once and no symptoms have re-emerged (fingers crossed).