TOPIC:

Got back to the small leak in the thermostat housing.



Radiator off, loosened the #4 pipe, and removed the assembly.



As I mentioned before and suspected, the combination of gasket and liquid gasket did create problem. I applied the liquid gasket in a conservative way, but it got squashed and didn't spread evenly. So, in a way, being careful is bad, and being generous like in other applications is even worse.

If you apply too little, there will be pockets through which the coolant will come and leak.
I you apply too much, the liquid gasket will break off and pollute the cooling system adversely affecting the pump and seals.

I cleaned all up, made a new gasket from a gasket material bought at Lordco (instead of a thinner 25 years old I still had from Japan), applied a thin layer of grease (as suggested by scotch), and a thin layer of silicone lubricant (as suggested by scotch).

While the gasket was 'conditioning', I used a 150 sand paper to improve the sealing surface. \before, I used the sand paper with straight line motions to clean and flatten the surface of the housing. I think that might have contributed to a compound effect resulting in creation of a weak point, where the leak occurred.





This time made circular motions.



Put all together, now waiting for the flange to replace the cracked one (pipe #3), and close everything up including the fan this time instead of just the radiator (which proved to be leak free)

As for the radiator cap, the larger seal was cracked and the smaller one OK. The smaller one is difficult to replace ( all riveted) , and there is one complete cap which has been suggested as a straight replacement of the whole assembly. In my case, I purchased a rubber plumbing seal which fits perfectly in thickness, I just had to trim it and cut a bigger inner hole. It went in fine and seals well at a cost of I think below a dollar (Home Depot)

These seals from Home Depot can be used to cut good seals for other components, as for example the radiator drain plug
I will be using a couple thicker ones between the forks air bridge and the headlight fork ears.

Just got a couple things with the flanges included in the bunch. They cam polished and I am very impressed! Usually, whatever comes from eBay comes in a very rough shape, dirty, dusty, rusty. This seller sold me a few of these and all are spotless clean and hand polished. I can relate! That's how I would be selling things. I really appreciate people putting some heart into these things.

Managed to install that missing one (#3), so I am ready to close the cooling system again. All the other five are chrome plated, this one just hand polished. Gives the bike more character!
Re-tightened the rest, tomorrow I'm ready!

Just a quick update.

The above grease and a thin layer of silicone gasket treatment suggested by scotch didn't work on the thermostat housing. Seems it worked on engine head cover or an oil pan, perhaps on not pressurized oil systems? I'm curious what scotch has on this.

When I first installed the housing it was fine and just had a very small leak, droplets, from just one spot when cranking the engine. Now, with the 'new' method, I was literally pissing coolant all over my shiny exhaust pipes. So, my verdict is - I will not use grease and silicone on this gasket.
Now I am getting a pro at installing and removing the radiator - it will be a fourth time.

I am also becoming a pro at taking new laptops for repairs. Using an external monitor now because the one on my brand new three months old only laptop (which was once replaced and once had to have hardware not properly functioning fixed) has a monitor working randomly only, so it will go out for repairs soon.
So, if anyone would wonder where I am, the repairs will take between 2 and 4 weeks, and I am not sure if I will be back on the forum until then.
Cheers!
Stan