MK1 Water Pump Gasket

  1. My model of MX-5 is: MK1
  2. I’m based near: Didcot, South Oxfordshire
  3. I’m looking for technical help or recommendations on: Does the genuine Mazda water pump require a gasket?

After getting my 1994 MX5 last year and changing all the fluids, filters, brakes, tyres and a few other bits, I thought it’s probably best to change the timing belt, accessory belts, crankshaft front oil seal, camshaft oil seal and water pump.
I’m looking to order the genuine Mazda water pump from MX5 parts which suggests “Mazda supply these pumps without gaskets as they recommend that you use a liquid ‘gasket eliminator’ instead”. However, it seems that you can buy a genuine Mazda waterpump gasket? So my question is, should I use the gasket (with or without some silicone engine sealant)? If I shouldn’t, could someone recommend a liquid gasket eliminator?

Thank you!

Hmm, it depends.

If there is any doubt I would do a dry fit with no gaskets and do the following two checks:

  1. Check the depth of the impeller behind the mounting face, and see if it fouls on the back when turned. Past posts suggest this can happen.
  2. Check the alignment of the belt pulleys, and see if they are in the same plane, a millimetre or two out will lead to excessive wear.

If it is almost perfect dry, then the liquid gasket in a squeezy tube is best. You won’t need much.
I’ve used RTV silicones in the past on assorted cars and they always worked just fine, but the science has moved on since then with a vast range available.

Otherwise, a proper gasket can pack it out not to foul on the block and hopefully raise the pulley into the plane. Thickness matters here so take a measurement or three to get it right.

Thanks Nick, that’s super helpful!
I’ll order the water pump and the gasket and do the checks you’ve suggested and see how it fits, that way if it turns out a gasket is needed, I have it.
Although, some of the parts I need are currently out of stock, the car is resting in my parents garage about 180 miles away and, lockdown, so it’s going to be a while before I can report back on whether the gasket is needed or not.

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