Hi all

During a recent under-house pipe inspection, I found one of my hot water pipes has a very slow leak at a T-junction. The leak was only apparent because the ground nearby was darker and a bit softer than the rest of the ground. No dripping nor puddles, so clearly very slow. 

The pipes are buteline, using the standard fittings. A plumber who visited once told me that buteline use their own sizes, so you need to use their tools for any work. I don't own a clamping tool.

My question is, if a fitting is leaking, can you just re-clamp it to stop it, or is it stuffed and needs replacing altogether? Just trying to decide the best way to resolve this, as I don't really want to have to call a plumber out just to tighten a fitting if I can do it myself.