1971 Heater core and hose issues.

[Rick Church]

After re-doing the engine compartment and cooling system on my car (71 Vette), a leak developed where the heater hoses connect to the heater core. I over-tightened the hose clamps on the hoses and crushed/crimped the pipes from the heater core so the hoses will not seal around the pipes. To retain the correct appearance of the engine compartment heater hoses, I simply joined the two hoses (at their ends) together with a three inch aluminum pipe and it (hose ends) tucked neatly into the space behind the passenger side wheel well. I'm somewhat concerned about the heater hoses sitting there with no fluid flowing through them. I need to figure a way to get the heater core pipes round enough to allow the hoses to seal. I'm looking at using a swege to round them out without dmaging the heater core where the pipes are soldered in place. Will the hoses be affected with no fluid flowing through them? Just a thought!

Rick in Tennessee

[Joe L.]

Re: 1971 Heater core and hose issues.

Rick------

If I understand you correctly and you've "looped the upper and lower radiator hoses using the aluminum pipe to connect them, the hoses WILL have coolant flowing through them. On Corvettes with an external supply tank, you must keep the heater hoses in the system and looping them as you described is the way to do it. On Corvettes without an external supply tank you could eliminate the hoses, altogether, and plug the manifold and water pump fittings. Of course, either way you won't have a heater.

You could try to restore the heater core tubes with an improvised tool. The brass used for the tubes is quite soft and is amenable to re-formation. However, are you sure that the problem with the leak is due to the deformed tubes? The solder joints between the core and the tubes are the most often source of leaks. They are also very "fragile" and easily damaged which, inevitably, starts a leak. If you haven't already damaged them, it's VERY likely that you will do so in any attempt to restore the tubes to their original configuration, especially if you try to do it with the core installed in the car.

[Jack H.]

Re: 1971 Heater core and hose issues.

From description given it's tough to know whether you 'blind' terminated each hose or if you did an effective bypass of the heater core by connecting the hoses together through a pipe union. Either way, you'll not 'hurt' the hoses; rubber is a hearty critter!

The Catch-22 here is trying to repair the damage to the heater core's inlet/outlet nipples. Not only were these 'round' but you should find 'bumps' near the ends intended to prevent hose clamps from slipping off. All geometry needs to be 'restored'.

This is complicated because there's not a lot of room to work with the heater core installed and taking it out do bench work is a pain.... If you grab hold of the inlet/outlet nipple and apply any appreciable 'side loading' force to it (pulling it in/out with respect to the firewall), you can wind up rupturing the nipple's sealing joint were it enters the heater core body. That's why service manuals always suggest undoing the hose clamps, cutting the hoses and GENTLY peeling them off the nipples during routine maintenance.

But, you might get lucky with swedge if you're CAREFUL not to move the ends of the heater core nipples very much when you attempt to straighten them. Worst case, you'll get everything back together to discover coolant is dripping onto the passenger cockpit's toe pan carpet.... If that happens, then you're in for a complete heater core change out!

[Paul E. Young]

Re: 1971 Heater core and hose issues.

Rick, Most radiator shops have the exact tool that you need to get the original configuration on the brass hose fitting from your heater core. They should be able to apply the plier like tool while the heater core is in the car. Then if it still leaks you will need to take it out and get it repaired. Best of luck. Paul

[Rick Church]

Re: 1971 Heater core and hose issues.

Joe, Jack and Paul,

The sentiments and technical aspects you each speak of are exactly what I am afraid of. I don't want to damage the heater core because I know what a PITA it is to get to it from inside the car. I guess I'll just live without the heater until something more serious requires me to get in the area of the heater core. Thank you each for the great responses!