10 replies to this topic

[MikeRotherham]

Hi,

Last November I replaced the blocked heater matrix in my car, flushed out the cooling system and rebuilt it all after a lot of cleaning out and getting bits powder coated. I have run the car a few times since then with out leaks but yesterday I went out to check under the bonnet and spotted the top of the cylinder head between the rocker cover and the themostat housing was wet. It appears that coolant in seeping out of the joint between the head and the bottom of the sandwich plate.

I did clean all the mating surfaces of the cylinder head, the sandwich plate and the thermostat housing and used 2 of green and grey gaskets from Minispares. There was some pitting of some of the surfaces. Before I replace the sandwich plate I thought I'd pull it all apart and reassemble using new gaskets and some sealant. RTV sealant has been mentioned in other threads. Can someone recommend a product I could use?

[unburntfuelinthemorning]

I find a thin coating of Hylomar universal blue very helpful.

 

http://hylomar.com/h.../#universalblue

[MatthewsDad]

As above, small amount of hylomar.

[RooBoonix]

I like to use Permatex no 3, and I find some of the gaskets supplied to be too thin. I used the thickest gaskets out of the several kits I had and they're sealing lovely.

I find the grey and red minispares ones rubbish, both of mine leaked

[Spider]

The Thermostat covers in some instances can be a challenge to get them to seal.

 

I had been using Permatex (Loctitie) No. 3 for years, but a few years back went over to an RTV sealant, which I've found better for these more difficult ones, as to a larger extent, it will fill gaps.

 

Also, I've noticed many Thermostat Cover Gaskets these days, as supplied, are rock hard, these will never seal as they have no 'give' in them. I use the thicker paper types, to check them for hardness, I just feel that they will bend OK. If there's no Engine Steady here, you can also use Cork types.

[whistler]

There is another possible cause. If one of the stud/bolt threaded holes has broken into the head chamber then water can seep up the threads and out through the top of the housing, dribble down the side and appear to be from the gasket joint. Have seen this one on a friends head. A bit of Hylomar in the threads worked.

[MikeRotherham]

Thanks for all the input,

 

The recommended torque for the bolts is 11 Nm.

 

Does everyone stick to this figure?

[unburntfuelinthemorning]

I do but I prefer to call it 8 lbf ft. 

[MikeRotherham]

I do but I prefer to call it 8 lbf ft. 

What type of torque wrench do you have?

 

The lowest mine goes to is 20Nm

[unburntfuelinthemorning]

I bought it fifteen to twenty year ago but I think it's this one:

 

https://www.sealey.c...ft---calibrated

 

And if you shop around:

 

https://www.ebay.co....tm/332617348332

 

It does have a scale in pounds but it's rubbish - the Newton metre one's a lot easier to use.

[MikeRotherham]

I bought it fifteen to twenty year ago but I think it's this one:

 

https://www.sealey.c...ft---calibrated

 

And if you shop around:

 

https://www.ebay.co....tm/332617348332

 

It does have a scale in pounds but it's rubbish - the Newton metre one's a lot easier to use.

 

Thanks for the info.