Something in the vicinity of the thermostat housing is drooling coolant down the block of my '78 240D, and I figured the first step should be remove the housing and replace the gasket and short water pump hose, or at least get a better look at where the leak is coming from. Can it be done without removing the York compressor? I'm not really sure where to start, because there are bolts on both the housing and compressor that look impossible to reach with the other unit in way. Or can I just remove the entire compressor bracket, with the compressor still on it? That would allow me a better look at the water pump too, which I haven't entirely ruled out.
Also, I've read conflicting posts via search as to whether to use a sealant on the gasket between the t-stat housing and head ... should I use Permatex in addition to the new gasket, or just the gasket?

__________________
1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)