I can recommend Radtec for service. I had a 10? year old rad that started a small leak near the core. Expecting to have to purchase a new one I rang Radtec and they suggested it might repair. I sent it off with a request for an additional vent pipe to be fitted as well as the repair. They tested it, repaired it, modified it and replaced a broken fan bracket. I rang them as I was keen to have it back ready for an imminent trip. They said it was in test and they'd get it to me ASAP. It turned up the next day. Rang them to say thanks and expressed surprise that they had released it before payment. They'd done that because I was in a hurry. Best of all the cost was very modest - a fraction of the price of a new rad and yes it's still fine 6 years later. By the way I now use bluecol antifreeze on their recommendation.