Hi Alex,

Glad you got the front suspension sorted out.

Those mushroom gaskets on top of the water pump are a common place for leaks. If they're not adequately compressed up under the head when they're installed then they can leak as they age and shrink. Worse still is if they're exposed to spilled or weeping oil from around the valve cover area then a cheap rubber gasket can go mushy and start to leak. That's where a genuine Volvo mushroom gasket can outlive a cheap aftermarket gasket.

I normally just use the gaskets that come with the pumps, which for me are either Hepu or GMB pumps. I've also used the Pro Parts Sweden gasket sets, which are commonly available. I consider them perfectly adequate quality, but nothing special. To help keep the mushroom gasket from getting oily and going mushy, I am a) careful to clean up any oil spilled during filling and b) use black RTV around the lip of the the mushroom gasket so oil can't collect in the gap under the head and get at the exposed rubber. Use a lever to pry up under the pump as you tighten it to make sure it's compressed under the head flange. Although gasket sealer isn't called for on any of the gaskets, many like me do use a sealer, at least on one side of the paper gasket. My weapon of choice is a non-drying blue hypalon gasket sealer. It stays tacky forever and allows me to slide and even remove the pump without damaging the paper gasket.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now