How do I check the old Heater Core?

[Georgia Flash]

Hey guys,

I have my dash out of my 75Z and you know that while it's out I should do a good inspection on the Heater core and related hardware such as the small rubber hoses and what not.

I have a couple of questions, how do I check to see if I need a new heater core (the car is not running and I have the old one out already)? Will the Datsun unit work ok with the chevy tree-fitty? (i am assuming that it will)

Thanks

[jimzdat]

One "old-school" method is to fill the unit up with water, then take an old 10-speed innertube; cut it opposite the valve stem--clamp one end onto either side of the heater core, the use your handy-dandy air pump to inflate the tube--put about 10-15 psi on it and check for leaks.

Works for radiators too, but you usually have to use a big BMX tire tube for the bigger hose fittings.

 

Can't tell you for sure yet if it'll work with the 350, but I see no reason why it shouldnt

[Georgia Flash]

Thanks Jim,

Believe it or not I am just getting in from the garage after working most of the day on the Z. I went ahead and ordered me a new heater core for about $79 and some change from Victoria British. They were the cheapest I found. I got prices from the low $79 Vic Brit core to the high $150 Auto Zone core. Go figure.

I had one of these puppies go out on me in the middle of the winter in my last ZX I owned. Spewed steaming hot anti freeze and water all over the interior. Not pretty. I decided to go ahead and bite the bullet and get a new one. The JTR book doesn't say anything about having to use a chevy heater core so I should be ok.

One thing I cant find anywhere though is the two heater hose metal pipes that come out of the firewall in the engine compartment. Every place I call tells me that these bad boys are not in production anymore Mine are a litte corroded.

[Guest Thurem]

As far as compatibility of heatercores go, the things that matter are the pressure and the temp. and those are the same, or very close, in almost any car (or bike for that matter) that I can think of. The two pipes for the firewall, why don't you custom fab them, that way you can make them so they fit the datsun heatercore hose size on one end and the chevy heaterhose size on the other end, I think JTR talks about them being different.

Thure