So I've just double checked the service records I keep and I was a little out earlier. Although the repair dates don't represent the failure dates as I did nurse things along with regular top ups for months here's when I've been changing things:
July 2015, 72,500 miles - new thermostat pipes and O-rings.
December 2015, 78,600 miles - new O-rings
June 2017, 88,500 miles - new viton O-rings, supported thermostat and banana pipe.
So my 3 sets of O-rings have managed 6k in 5 months, 10k in 18 months, and now 4.5k in 9 months. I'll probably get to 7k in 12 months with the current set.
I really don't want to go down the k-seal/radweld route, but I have wondered if it could work from the outside. If I could pour a small amount into the gap above the o-ring, where I can see the coolant at the moment could that work?
Alternatively I've got some fernox lx-s (leak sealer) for the central heating which I'm tempted to try.
These are bodges I know, but doing a proper job doesn't seem to be working.
