Water pump housing gasket

[Andrew S]

When you fit a new pump you get the 3 gaskets and you choose one based on measuring the gap with a feeler gauge. Is it that crucial or is it a case that the housing wont foul the top of the shaft? If so, is there a problem with just fitting the thickest one of the set? Thought I would ask before carrying out this procedure

Cheers
Andrew

[wilf]

IIRC, the gasket thickness selection is done to ensure the correct clearance between the tops of the water pump vanes and the cover. For pumping efficiency this needs to be as close to zero as possible, but for mechanical tolerance reasons there needs to be a clearance.

[Andrew S]

Cheers Wilf that makes sense

[Knockwurst]

Andrew, you do need to be careful when measuring. On my first attempt I didn't choose thick enough. Everything was ok until the engine was fully hot / expanded, when slight contact between the pump and housing made a noise. Another 0.010" fixed it.

Simon