Last installment we looked at the heat exchanger box itself, this time I’ll focus on the bits that hook it up and control the incoming hot water: the heater valve and the push/pull cable that controls the valve. The first generation of Sprint’s had a heater valve (1483.54.711) that looked not far removed from a garden tap and you actually had to pop the hood and get out to turn on the flow of hot water to the heater core (if you didn’t realize you were going to want heat before you started out). At some point this was deemed a little old fashioned so a cable operated valve was put to use -cousins of which can be found on Alfa’s for many years to follow.
Valve failure mode(s): hardening of rubber diverter seal, oxidation leading to through pits or breakage, loss.
Control cable failure mode(s): still/difficult operation, cable breakage/cut leading to too short, loss.
The current state of the parts supply has:
- The early style heater valve available in reproduction from most sources that service Giulietta’s.
- Diaphragm seals available to rebuild original 1493.54.709 heater valves.
- Replacement valves that with a little rework will work in place of 1493.54.709.
1493.54.709 with new diaphragm seal installed. Like all rubber things, it just got hard and cracked after 50+ years. The inner plateau seals against the port in the valve body, keeping the water out of the core when not wanted, the outer ring seals to the body to keep it from leaking when it’s open.
Continue reading “Heater part 2: Heater valve 1493.54.709 and control cable 1488.31.723”
