Dear Radiator fans;

I cleaned a big radiator I got used and was pressure testing it in a big bucket of water with a dr. Drop and a co2 tyre inflator.

It is not holding pressure.

I only load it with a few bar of pressure.

I see a slow bubbling where the copper tubings are connected to the steel manifold plate with rubber grommets.

I changed the thin rubber gasket with a new o-ring.

It is leaking slowly at both ends.

Is the tubing grommets going bad ?

Can I reseal it with a soft silicone bathtub calk or some other goo or glue?

Has anyone had problems with these radiator rubbers getting old and brittle?

Are they replaceable? If I send it back to Germany can they rebuild this or can a radiator shop re-build this?
The grommets seem to be press fit and may require special tooling to force the rubber over the tubs and manifold plate?

I see new units available for 200 or so USD. I am thinking of buying a new unit and sending the old unit for factory overhaul.
I can always find a place for a spare radiator somewhere.

I noticed the slow leak with leaksheild reporting this radiator loop as leaky.

Photos and bubble video on demand.

2 bar or so.
i found the leak in one of the copper tubes. I tried fixing it with uv cure epoxy and coating the inside of the tube then curing it.
It was not at the grommet bulkhead.


i think I'm going to buy a new radiator.