heater hose routing??

redfastback · Sep 8, 2007

how is everyone routing the heater hoses from the core to the engine? i put in a new heater core 2 years ago and it has worked flawlessly until the other day. i have heard mentioned that if you hook up the heater core backwards, you'll blow it up. i have the driver side heater core hose going to the intake manifold and the passenger side hose going to the water pump. i have seen many others just like this yet my FSM shows that the pass side goes to the intake side??

what's the scoop? any insight?

Suregrip391 · Sep 8, 2007

Here is how I have mine routed, no problems.

Longgone · Sep 8, 2007

I don`t think you have to worry with the core blowing up, but they do work more efficiently when they`re plumbed right. The best way to remember how they go (no matter what engine you have)is: the drivers side of the core always goes to the connection closest to the radiator.

sl7732 · Sep 10, 2007

This might sounds a little off but, my 73 Dart has differant size outlets on the heater dore, differant size heater hoses and the outlet on the intake is a differant size to the water pump outlet so its very difficult to get the hoses on incorrectly.
Is this not the case on all year Mopars?
BTW, changing the heater core on the Dart was much easier than the one on a 94 Town car that I had for a while, that required removing the entire dash...FUN....

73dusterPa · Sep 13, 2007

yeah , I'm pretty sure my 73 duster has 2 different size fittings also !

70Duster440 · Sep 13, 2007

I believe some years (don't know which) had identical size tubes (large), and others had big and little.

ValiantMike · Sep 13, 2007

Suregrip391, that is one of the nicest engine compartments I've ever seen. Mike

redfastback · Sep 13, 2007

i think i have 1 bigger(5/8") and 1 smaller(1/2"), but on a 70 later engine and car they were both 5/8" hose. the funny thing is that it stopped leaking. i should have worded it better, it didn't blow, but started leaking when i was getting on the freeway, which by habit i leave it in second, punch it 1-2 shift at about 5400 rpm and then hold out to third till i feel like it.....about 5000 rpm. i do have it plumbed backwards to what suregrip and longgone have. but it has worked flawlessly. i did get about a 1/2 turn on the hose clamp. my buddys is plumbed how i got mine, so is dgc333's on his site.???? what happens if its backwards??

Longgone · Sep 13, 2007

If you look at a heater core you`ll see that one tube enters the core at one end and the other in the center so you probably will not realize the greatest potential for heat exchange if you plumb it in reverse.

RPMLegends18 · Sep 13, 2007

Heres mine now, and what it was. It was before the smaller one ran along the fenderwell and the big one ran right up against the head. So I just ran them both over there, I like how Suregrip391 has his, and how nice his engine compartment is...=)