[Plodder]

I’m replacing the water pump on my 81 416 Rover with DOHC D16 engine and wondering whether I should use sealant as well as the rubber o-ring supplied .
Another post suggests using Hylomar sealant in addition to the rubber o-ring fitted to the pump.
Just wondering what anyone else has done.
The post also suggests lubricating the seal before assembly, is this with water or a bit of vaseline?

[g259fsg]

Silicone grease is usually safe with rubber seals, or red rubber grease. Lubrication is good to ensure the seal beds properly. If the mating surfaces are good, the O-ring would normally be sufficient, but I haven't seen the actual assembly.

[Plodder]

Thanks for that reply.
Will give it a clean up and remove the existing sealant applied by the garage who did the water pump back in 2016.
I’ll see what the mating surface looks like once I’ve done that.
Thankfully the replacement pump I brought a year ago is the correct one, as I don’t think they would have exchanged it after so long.
Hoping to get the power-steering and alternator brackets back from the powder coaters next week so I can finally get the car back together and working again.

[Johnny 216GSi]

I'm just wondering if just rubbing it around with a drop of oil from the engine is all that's needed.

If you think about the rest of the engine, the oil filter, the cam and crank seals, etc. then a garage would just rub a drop of motor oil on all those seals prior to fitting.

It's only to stop the seal not seating properly or "holding off", i.e. bunching up somewhere and being thin elsewhere. The oil would just make it slippery enough to move around and prevent stretching and bunching as the water pump is tightened up.

You won't really be able to "improve" the seal with anything. I've seen that some people use high-temperature silicone sealant to seal things like the spark plug gaskets and the cam cover gasket to stop leaks, but it's nowhere near as good as replacing the gaskets with new ones. You also run the risk of some of the silicone breaking off and then clogging oil and/or water ways/galleries which would cause premature engine failure. The water pump is in a fairly busy area of the engine, so this might happen. I've previously used blue Hylomar on the cam cover gasket but have since carefully scraped it off and now I only ever just replace the gaskets and fit with a drop of engine oil to lubricate, if anything.