Hey Mike – you are not pushing the pin completely out of the link are you? If you’re having trouble with chain breaking, and trouble with pin pushing – I think you’re on the right track – might want to check into a different chain breaker and see if you get better results. The one I use, is in fact an RLV, but I have never broken a chain, or the pin on the tool. Maybe the breaker you’re using is damaging, or bending the link and putting just enough stress on the chain to break it under a heavy load?
Is this the only place you break a chain? I wouldn’t think braking alone would have anything to do with it, but I would imagine heavy braking combined with a downshift could cause a pretty heavy load on the chain?