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1) Last Tuesday I finished replacing the head gasket in my 1984 245. The job went fairly smoothly and the car ran great...for a few days. Then it reverted to the exact same symptoms that led me to believe the head gasket had failed in the first place (slow coolant consumption and a brief spike in the temp gauge as the engine came up to operating temp). Over the weekend, on one of my coolant checks, I noticed I had lost all cooling system pressure when I pulled the expansion tank cap off. No hiss whatsoever. Imediately after the work, I got a loud hiss; the system was obviously running at designed pressure then. I have not noticed any leaks yet or any discoloration in the expansion tank. Could the head gasket have failed already? In reviewing the work I have done, I have a few possibilites. Are any of the following plausible?
A) I noticed after driving the car for a few days that the left edge of the head gasket under the intake manifold does not perfectly follow the edge of the head. Two "ears" of the gasket jutt out from under contours of the head. (The area I am trying to describe is just behind cylinders two and three, on either side of the knock sensor.) The front and rear edges of the gasket line up and there are no issues on the right side. I also remember lining these ears up when the head went on and I do not remember encountering any resistence in threading the head bolts. I have not noticed any coolant weepage, but this still concerns me.
B) During reassembly, I forgot to lightly oil the head bolts until everthing was already in place. They were torqued to book values (15, 44, 90 degrees more). Then when I realized my mistake I tightened each bolt about 5 degrees more. Is this a possibility?
c) I had the head machined to account for a slight warpage issue (see my earlier post: OK,The Head's Off, Now I have a Question...). When I got the head back from the machinist, I remember being able to clearly see the semi-circular arcs made by cuts from the milling machine, but I do not remember if the bottom of the head was rough/ridged. Would a head mill leave a rough enough surface to destroy a head gasket in three days/ 200 miles?
D) After putting on 100 miles, I flushed both the coolant and the oil and oil filter. I replaced the coolant when the engine was still warm to the touch (warm enough to feel it when I rested my hand on the cam cover, but not hot enough to burn myself on the coolant or the engine block.). Would this be enough to crack a block or head or destroy a head gasket? Also in line with this question, I ran the first 100 miles with distilled water only (no anti-freeze). Could this factor in?
2) I know with the loss of cooling system pressure, I need to have the system pressure-tested to pin-point what failed. The last time I had it done, the dealer was the only one that had the correct tool and the cost of the labor was outrageous. In my wish to perform the pressure test myself, I had this idea: I have a Motive brake bleeder that I have used less than a half dozen times in the last two years. The last time I used it, the clear vinyl line from the bottle to the cap burst. I have recently replaced the crimped-on line with a similar hose and hose clamps. If I could somehow clean all the brake fluid out of the pressure bleeder, could I use this tool to pressurize the cooling system with air as the Bently manual shows (teeing into the small diameter expansion tank hose)? What's the worst case senario for mixing DOT 4 brake fluid and Genuine Volvo coolant? The only reasons that I am considering this option are I already have this tool and the pressure gauge on the front of the bottle is the correct resolution for testing the cooling system.
Thanks in advance,
Nick
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