Fitting new water pump

I'm just about to start fitting a new water pump to a 1.8 1990 golf clipper. Got a new Circoli pump and thermostat from ECP. On reading the note that comes with the pump it says to fit the pump with "Circoli sealant". Now i've had a look at the topics on this forum and few Youtube videos and no one seems to use any sealant. Everyone just seems to put the new O ring on and bolts it up. Does anyone have any views on this?? Ive no idea wher to get this sealant but im sure gasket sealant or silicone would do the job.

There is 2 types of water pump for sale, the whole pump which bolts to the engine block with 3 bolts or you can just buy the side of the water pump which bolts with about 10 nuts and bolts, which version did you get?

its the whole pump ive bought complete with flange for the front pulley. it has 4 fixing holes.

Yes you are right about the 4 fixings I forgot about 1! There should be a rubber O ring with the water pump? You just need to clean the block where the water pump fits a little scraper or sanding may help then put a little smear of grease (I mean a little do not go mad) all over the rubber O ring fit to water pump then fit to the engine block. You should also have a rubber O ring with the new thermostat do the same with that, I think it's the same size O ring as the water pump?
No need for any special sealant. I also put a little smear of copper grease on the bolts which fit the water pump so they don't seize inside the water pump housing.

Water pump fits here.

Thanks for the information. Thats basically how i intended doing the job but the leaflet with the pump threw me a bit talking about sealant. let's hope I don't manage to shear a bolt. LOL
Once again many thanks for the sharing of your knowledge.

If the bolts are hard to undo losen them a little then do them back up then undo a little and do up a little and so on…… What this does is clear the treads of rust and can sometimes stop the bolts from shearing off.
Good luck and let us know how you get on. 

OK that's the new pump and thermostat fitted. Only problem was the bottom right hand bolt sheared off just under the head. This left quite a bit sticking out from the block once the old pump was removed. Heat and pipe freeze soon got it shifted so all in all not as  bad a job as I was expecting. Other thing was I had to pack out the pulley as it was fouling the timing belt cover. just used 3 washers under the pulley which was enough to move it so it was free. Again thanks for the advice and the pics. Another job done on the 1990 golf clipper.