I am going to be changing the water pump gasket soon, and in my opinion there should be no sealant used on the gasket or mating faces.

But on numerious television programs I have seen, (wheeler dealers to name one) the mechanics insist on using sealer between the gaskets and mating surfaces

Just wanting your opinions on the subject and in particular to 1.3 felicia applications. e.g. sump, timing chest, ect, ect.

Clean them well, and DO NOT USE sealant, but dont talk to me about gaskets 😰

A good original gasket doesn't need sealant.

Doesn’t it depend in the type of gasket?   

On 06/01/2022 at 19:45, R_U_AFA said:

I am going to be changing the water pump gasket soon, and in my opinion there should be no sealant used on the gasket or mating faces.

 

 

I had in the past problem with the water pump gasket, the mechanic did not apply sealant on the new gasket.

 

In some other cases as below:

 

Oil pan

Transmission cover

Valve cap

Valve guides

Timing cap

Differential cap

Transmission crankcase

Water pumps

Thermostat housings

 

they use but when they keep the original gasket and it's in good condition.

I think it depends on some variables.

- Quality of gaskets.

- Mating surface condition.

- Some mating surfaces endure more physical stress than others.

- Age of the car.

 

My car is old and it seems a lot repair work had been done before.There is black sealant on every mating surface.

I used sealant between carburetor and intake manifold and very satisfied with the result.

I didn't use any sealant when mounting intake and exhaust manifolds and I got both exhaust and coolant leak.

 

I'd say, if you suspect the quality of the gasket or overall condition of the mating surfaces, use sealer.

33 minutes ago, R_Blue said:

There is black sealant on every mating surface.

Personal account - a friend's neighbour had an S100. Every 2 or 3 months he dismantled the engine for no adequately explored reason. The point is that I'd not assume "repair work" in the sense of actual replacement or enhancement of components.

31 minutes ago, KenONeill said:

The point is that I'd not assume "repair work" in the sense of actual replacement or enhancement of components.

That's wise. I agree.

As others have it can depend on a number of factors.  I only used the paper gasket on my 1970s engine water pump and it's been fine for over 12 years so far but I've had to change the hot water tap (it is just that, heater valve on most other cars) and aluminium(?) thermostat housing, which are both on the cast iron cylinder head, a few times for various reasons.

 

Initially I used some blue Universal Hylomar on the heater tap as it sits on a pedestal and needs a copper shim so has potential to leak and is in an awkward place to deal with.  Later I listen to all the mechanics and engineers that said you only needed the gaskets - I got leaks and weeps.  I was very thorough always with cleaning before fitting gaskets.

 

I found (Hylomar) Hylotyte Red 100 to be best at sealing for coolant leaks, as it's semi-hardening you can nip up the fixings in situ to stop weeps if it's been applied and there's ben movement from vehicle use and heat cycles.

 

https://hylomar.com/en/hylotyte-red-100/