The BT-50 we purchased at auction was blowing coolant out and not reclaiming it. The cooling system was also staying pressured after the engine had cooled down.
My mechanic suggested it could be the EGR cooler pressurizing the cooling system but unfortunately after bypassing the coolant lines from the cooler the system was still pressurizing
I had noticed after I purchased the car what looked like aluminum filings in the radiator and had assumed (incorrectly) that it was the water pump failing and grinding it’s housing. As there is no recent service history I assumed the timing belt was due to be done and it was little more effort to replace the pump at the same time. Now that I know there was a head problem the metal powder was probably some sort of stop leak additive.
I found a workshop manual online and also purchased a CD off eBay (which had an unsearchable version of what I got online for free) with torque values and other errata.