One way to identify the leaks is by the color and smell of the fluid. Motor oil, atf, and coolant are easy, due to coloration and such, plus where under the car they appear (drops on the pavement/ground.
1972 model year? Are the leaks under the rh floor mat? Here's what I found out on my '70 Monaco Brougham and on our '72 Newport, plus from a few other conversations with our local Chrysler service people, back then.
IF the leak appears to not be coolant, it is a/c condensate. How'd it get to be "a leak"?
When I got my '70 Monaco used, I was going through it one day and removed the rh frt OEM floor mat. Under it was DROPS of moisture. Didn't smell or feel sticky, but was there in abundance. So I put the floor mat in the trunk for things to dry out and watch for leaks. There were none I could see or find. I checked the lh side and nothing really there, as with the rear mats.
My initial suspicion was temperature changes, over time, from exhaust heat from the floorpan and a/c cooling the interior, over time. The hard vinyl in the mat would trap any moisture and keep it from evaporating.
I also looked at the bottom of the a/c case. I had heard of hvac case leaks from dissatisfied customers who'd had their hvac cased re-sealed and leaks persisted. When I laid in the rh foot area and looked up, closely, I saw the reason!
The a/c case is in two halves, with some slip-on nuts on the backside, with pointed-ed bolts that go in from the passenger side of the case. The gasket between them is a somewhat soft, but with a harder outer skin. Nothing unusual there. BUT that gasket goes against the slip-on nuts, creating a small gap where the backside of the nut section slides onto the back-half of the case, leaving a small gap. The stiffer skin of the gasket will not conform to seal that gap, so water can find its way to those gaps and onto the upper section of the carpet. When the car is new, the normal drain mechanisms are there, so things work as they should.
The old-line Chrysler service manager said they also deleted the drip tray from the Fuselage cars, which the earlier cars apparently had, so the bottom of the hvac case was suddenly vulnerable to ANY moisture in that area.
How to fix this? Two possibilities. IF the hvac cases are apart, add a dab of silicone sealer to each of the side of the slip-on nuts to seal those little gaps the gasket will not conform to. The nuts "aren't going anywhere", so that is a good option. The other option would be to slide the slip-on nuts off and find some new flanged-head nuts of the correct internal and external dimensions to go in their place. That would let the gasket seal against the bare flanges correctly and reliably against the two flat sides of the hvac case flanges.
In relation to the hvac case drain issues, also make sure the drain tube out of the rh lower cowl is also free and open. Many times, it is just a tube sticking out of the cowl, but might have a right-hand rubber attachment slid onto it, to keep any air pressure from under the hood from keeping the drain from working, directing the water downward and then to the ground. Many GM cars have these and their slots on the bottom side can get clogged and retain water in the hvac cases, by observation. One day, at a customer's shop, he had a mid-'80s GM fwd car on the lift. I was looking around from the bottom and noticed this a/c drain with grunge on it, I touched it and about 1/3 gallon of accumulation gushed out. YIKES! GM, by observation, does a good job of sealing their hvac cases!
I mention this area as many don't consider such in a car. But it seems to be more common than not on Fuselage cars, from what I suspect. As the auto-ragted carpets don't seem to mildew easily or smell of moisture, under a hard vinyl floor mat (or rubber-backed carpet mat), one of those things that's there but never noticed during ownership.
Of course, if it's a heater core leak, the inner section of the windshield will fog when the defroster is used and any moisture on the carpet will be a bit sticky and have a hot coolant smell to it.
I wanted to mention this area in case this is what you might have found and were questioning about.
So, let us know about your concerns,
CBODY67
...My main mechanic is here in Prior Lake and a lot of work was done relatively close by in Mankato. PM me if you like.
