Just did a coolant flush, changed new expansion tank, black cap with 75kpa (aftermarket 'OEM'? from fcpgroton), new upper and lower hoses, and new radiator to tank hose. The procedure went relatively smoothly, except for a stuck thermostat housing nut, and big mess when disconnecting the lower hose. Anyway, I filled up with Prestone 50/150 coolant (claimed to mix with ANY color coolant for any make of cars), let the engine idle for 5 minutes, then did another drain/refill. Then I brought the car out for a 30 miles run with full AC. It did not overheat, so I figured everything was fine. I popped the hood and checked for leaks. When I grabbed the upper and lower hoses and tried to squeeze them, to my suprise there was very little resistence, as if no pressure inside. I did not check how hard it was before the change, but on my other cars, the hoses feel very hard at the operating temperature. Is this normal with the black cap? The car seems to run fine though.
btw: one of the nuts for thermostat housing is stuck. I tried some 'brutal force' and partly rounded it. In the fear of breaking the stud I did not go any further and leave the thermostat unchanged. What would be a safe way to loosen it? This is the first ever 10mm nut that I could not break loose on the cars I have worked on. THanks
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1994 944NA 100K miles