Well, the "conservation of annoyance" is in full effect. The every-other-year emissions check was due on the 328, so I figured I'd go for it, despite the car having sat out the winter. After a brief "Italian tune-up", I took it to the local garage for a rolling road test. The car passed with flying colors, and the owner/mechanic there complimented me on a well kept car. So I was feeling good as I drove it the mile or so home from the garage. Until I stopped to back it into the garage. I look out the back to see Old Faithful geysering from the vents on the driver's side. The 20mm (3/4" i.d.) hose (122221 in the parts catalog) from the expansion tank to the T down in the clutter had split about two inches worth, spewing coolent all over. The coolent temp had just started upwards, so I backed it into the garage, shut it down, washed the antifreeze off the bodywork and hosed down the driveway to dilute the spilled coolent before the neighborhood critters could get to it. I picked up some 3/4" id "heater hose" from a local auto parts store, but the walls don't look all that thick. So the question is just how much pressure does the cooling system run? Does it take a hefty hose to hold it? Or should I put the thinnest hose where it's easy to replace, rather than putting hosezilla here and letting something harder to reach go next? (Don't mind the posting time: I didn't know that there were "screech owls" around the DC area, before.)
That hose's little brother just blew on my 328! I'm guessing yours is the lower hose going onto the expansion tank? Mine is the upper one, the smaller diameter hose. Anyway, system pressure is set by the radiator cap on the expansion tank. Original caps were 0.9 bar (13 psi), a common replacement is 1.1 bar (16 psi). Most American cars that use the kind of heater hose you bought run 16 psi caps; I have an old musclecar where the heater hoses and core are always exposed to full system pressure (16 psi) and it's worked fine for 40 years. So I'm thinking you should be OK.
Thanks. Yes, it's the lower. I'd found the 1.1 bar info with a search, but I couldn't remember what "regular" cars had on their heaters. My Celica AllTrac was made during the rally team's brief experiment with an un-pressurized cooling system, and my last american car was during the Nixon administration. The upper hose (and most of the cooling lines I could see) are fairly new Gates "safety stripe" hoses. The one that blew seems to be the exception.
He's got it....the .9 caps should be replaced with 1.1............ Whatever that means, in PSI...LOL!
