Hello folks, just having a bit of a drama with the cooling system on my freshly rebuilt ‘56 XK 140 FHC, so I wondered if you could help me?
I have an alloy radiator plus new hoses and reconditioned pump etc but all other elements of the cooling system are standard, including an original AC Delco 72 deg bellows thermostat (installed with giggle pin at 12 o’clock). I have the heater valve set fully clockwise to open and am running a 4 PSI rad cap. I checked the heater unit and the heater valve before reinstalling them and both are ok.
Having filled the cooling system with 60/40 water/antifreeze mix, when I run the engine and it gets towards thermostat opening temp, the bypass hose dramatically parts company with the inlet manifold and dumps several pints of coolant all over the place! It’s done this to me twice… I have removed the thermostat to check its operation (all ok), so before I soak the engine bay again I thought I’d seek some help!
It feels to me as if I have an airlock somewhere that is causing the system to over pressurise or conversely create a vacuum that’s pulling the hose off the inlet manifold? Perhaps I am not bleeding the system correctly when filling it? I wonder if anyone has a tried and tested process for this? I’d be most grateful for any help.
Thanks in advance, Jon.