Hi all, recent new owner of a 1987 Catalina 30 Mk II. Wondering if someone can help me understand the interaction between the two coolant expansion reservoir bottles on the boat.
The engine and its overflow bottle are down low, of course. The hot water tank is higher, in the port side cockpit locker; and its bottle is positioned above that.
Two things I notice, and I don’t understand the setup. Firstly: the coolant reservoir bottle at the engine never changes its level at all. Secondly: the upper bottle (above the hot water heater) has a tube running from the *bottom* of the bottle, that terminates near the engine and carries a “pressure release” label. It consistently empties coolant into the bilge a little at a time when the engine is running - enough that I’ve stuffed its end in a little plastic bottle so I can keep it out of the bilge and reuse it.
Result of this process is that the upper bottle slowly empties itself. I keep having to transfer coolant from my collection bottle back into this upper reservoir to meet the minimum level identified on the bottle.
On one occasion the upper reservoir emptied out completely without my noticing it. Next thing I knew, I had an air block in the coolant system and the engine began overheating. Did emptying the upper bottle cause that? Coincidence? Dunno.
So, what’s going on here? Should I just allow the upper bottle to empty? Is the “pressure release” tube on the upper bottle attached in the wrong place, needs moving from bottom to top of bottle? The reservoir bottle at the engine has its overflow tube mounted at the top, seems much more logical. “Inquiring minds want to know”…
The engine and its overflow bottle are down low, of course. The hot water tank is higher, in the port side cockpit locker; and its bottle is positioned above that.
Two things I notice, and I don’t understand the setup. Firstly: the coolant reservoir bottle at the engine never changes its level at all. Secondly: the upper bottle (above the hot water heater) has a tube running from the *bottom* of the bottle, that terminates near the engine and carries a “pressure release” label. It consistently empties coolant into the bilge a little at a time when the engine is running - enough that I’ve stuffed its end in a little plastic bottle so I can keep it out of the bilge and reuse it.
Result of this process is that the upper bottle slowly empties itself. I keep having to transfer coolant from my collection bottle back into this upper reservoir to meet the minimum level identified on the bottle.
On one occasion the upper reservoir emptied out completely without my noticing it. Next thing I knew, I had an air block in the coolant system and the engine began overheating. Did emptying the upper bottle cause that? Coincidence? Dunno.
So, what’s going on here? Should I just allow the upper bottle to empty? Is the “pressure release” tube on the upper bottle attached in the wrong place, needs moving from bottom to top of bottle? The reservoir bottle at the engine has its overflow tube mounted at the top, seems much more logical. “Inquiring minds want to know”…