Heater Core and Heater hoses ?

[Bunky67]

I'm getting ready to change my heater core in my 77 CJ5 with the older style heater with the blower fan inside the dash. it was bypassed a while back, because of a leak,

Today I went and got a new one and the tubes where the hoses hook look to be the same size, are they supposed to be ?

also what hose runs to where on the engine ?? My tubes set beside one another as they come through the firewall

Can someone tell me the heater hose sizes and how there routed ?

 

[csuengr]

Welcome to one of the many moronic things AMC did. Yes, they are supposed to be the same size on the heater core. However, you may have noticed that the fitting on the water pump is 3/4", while the heater core is 5/8". I went to ACE and made a reduction adapter from brass fittings. Doesn't matter what hose goes where.

...and someone will prove me wrong in 3...2....1...

 

[danc9]

Sounds good to me, I just got a plastic 5/8 to 3/4 coupler from O'Reilly.

 

[Tinman22]

Yeah sorry had too do it!! On some applications if the hoses are the same size the hot water as it cools looses volume and creates air in the core causing a gurgling sound in the dash !!!! no really no joke . The smaller hose helps keep the pressure the same reducing the noise. Stop laughing I'm serious!

 

[Bunky67]

Ok Thanks for the Replies and after checking there is already an adapter in line where they connected the two hoses to by pass the heater core,

but one more question does the heater core just sit in the heater box or do I need to put some type of insulation around it ?

Thanks Again