I have a 1989 f250 with a 7.3l diesel. About a month ago, it started blowing white smoke, then hydrolocked on me (three times). I've done work on cars, but never a head gasket. I pulled it apart, but i didn't clean the old gasket off that great, I just wirebrushed the surface. I also put the gasket on upside down, blue side up. The truck ran, and drove ok, but had a noticable lack of power. I messed with the timing some, but with no luck I decided to do the gasket again. (the truck wouldn't start without starting fluid, it had to crank too long and the batteries died) I cleaned it off real good this time, and put a new gasket on right side up, put it back together, and it was leaking, from the back it seems to me, and that is where some smoke showed up with a shot of starting fluid. I pulled it apart again, thinking that I bumped something during installation or something like that. I just finished installing the third one, with the same results as the second, it is leaking from the back of the head somewhere. There were no cracks that I could see, the head seemed flat from what i could tell, I don't have a machine straightedge or anything though. I am at a loss as to what to do next, could the hydrolocking have warped the head? I am also selling this truck when I'm finished, if anyone wants it knowing it needs work to save me the trouble that would be fine as well. THe truck never overheated, and it drove when I did the first upside down, not cleaned off gasket, but it is leaking like crazy now. I torqued it according to the hayes manual, 65-85-100-100. Anyone have any ideas?

 

how good is your torque wrench, did you crean the mating surfaces with any kind og parts cleaner, did you clean out the bolt holes with a tap, olied the bolts with a light oil before putting them back in, a wirebrush may have scrached up the deck too much

 

The head and block mating surfaces must be oil free when you install the gaskets.
Also as mentioned you need to run a blind tap in the bolt holes to clean up the threads.
Also clean up the threads on the bolts.
Preffered is new head bolts.
A very light application of assembly oil on the bolt threads so it torques correctly.

 

the wire brush I used had very light bristles, no way it could scratch anything that hard, it's a very soft brush. I cleaned the bolts nice, and applied oil, but I didn't tap the holes. my tap set is at home, I'm at colllege, so i figured it might not be a huge deal. would it be ok to overtorque them to account for it, so I don't have to get another gasket? the bolts all went in real easy, hand tightened till they hit the head. It doesn't seem like that would make a huge difference, but I really don't know.

 

I also used carburetor cleaner and paper towels to clean the mating surfaces once the gasket was completely removed.

 

How about thinking about a possible cavitation problem.........

 

Yeah I wasn't sure when i started the project whether it'd be a head gasket or cavitation, but I got it apart and can see on the head where the water was leaking into the rear cylinder. I'm going to try some soapy water around the head and see if anything starts bubbling like crazy when i turn the engine over.