Miata leaking coolant: any advice for replacing the water pump?

Hi all,

for the last few weeks, I've had to top up my radiator overflow tank every couple days. I took a look under the car and noticed coolant dripping from behind the timing cover, so it looks like it's time for me to change the water pump. I guess I should have changed it last year when I changed the timing belt, even though it wasn't leaking then. D'oh!

I've had good luck with Beck Arnley parts in the past, so I'm planning on getting that one from Rock Auto. Is there any benefit in using RTV in addition to the new gaskets that come with the new water pump, or should I not bother with it?

While I'm in there, I was thinking of changing the gasket that seals between the thermostat housing and the head, but I couldn't seem to find the part on Rock Auto, I could only find the gasket for the thermostat housing outlet end. Any advice?

Have you considered doing the coolant reroute at that time?

949 Racing has a good pump with a cast impeller for a price that's not much more than the discount houses.  And unless you've done the timing belt very recently, you might as well do it while you're in there... you have to do most of the work to get to the water pump anyway.  Don't forget to replace the o-ring for the coolant mixing manifold pipe while you're in there.

As far as RTV, I usually use some on the WP to mixing manifold gasket, and on the WP side of the WP to block gasket.  Never had a leak and the block cleans up easier for the next one.

To replace the thermostat neck gasket, you will have to remove the cam gears to remove the sheet steel cover.  I wouldn't bother unless it's leaking.  Be careful with the thermostat cover and neck... they are very fragile.... 

We have good quality pumps AND the O-ring for the thermostat neck

The big reason for a thin smear of RTV on the gasket is to keep it in place when you're offering up the water pump to the car.

Only recommendation I have is make sure you use a quality water pump. A generic over the counter auto parts store pump cost me an engine.

Oh and while you're in there might as well replace the timing belt since it has to come off to R&R the water pump anyway.