does anyone happen to have a pic of the routing for the heater core hoses??? mines been dissconnected and one of the hoses is plugged w/ no evedince of where the other line is.....i see the two connectors on the core...i have an 85, z28..

will someone with some input please respond!!! ive got the some problem only in an "86 z28, someone cut all the hose and rerouted a few... ive no idea of where they should be! please help!!!

It's not really hard. If you want to use the stock style hoses grab some from a junkyard with the diverter valve.

Otherwise you can just run a hose from any port on the motor (usually on the intake somewhere) to the heater core, and then the other hose to a return fitting on the radiator.

Check the radiator for a fitting and look for a plug on the intake.

And my heater core was bypassed for this pic, but you can still get an idea of what the stock routing is like. Notice the fittings in the intake and the hose running down to the radiator. You dont really need a diverter valve though.



And chances are they cut and rerouted the hoses because your heater core is bad. Just an FYI. Be prepared to replace the heater core.

I have the heater hose diagram. If somebody wants to host it, I'll send it to them. I get about two PMs a week asking for it.

Please email me at KenNguyen2@gmail.com

I'll host the pix for you.

Most of the time it's standard Chevy water hose routing... One hose from the outlet of the water pump to the core, the other to the intake manifold. The cars with the nipple on the passengers side of the radiator, use that nipple instead of the water pump nipple.

It gets a bit more confusing with the diverter valve... Generally speaking, the cars without A/C don't have a diverter valve. On those cars the line from the intake goes directly to the heater core.

Thank you for posting that picture.

I have a small problem though.

I am running a GM Goodwrench 350cid crate engine with Edelbrock intake manifold and Jones Racing Products water pump.

The water pump has 2 pre-tapped holes which I think are for suction since they are on the same plane as the lower radiator hose.

The Edelbrock intake has 2 holes, one on either side of the thermostat housing.

The tech guy at Jegs told me:

This is fine, but I don't think my water pump has a port for coolant into the heater core. It's an aftermarket pump. I'm trying to get a response from the manufacturer but they did not respond yet.

I'm running a full Vintage Air system and they recommend:

Hot coolant from intake manifold into heater core
Cold coolant from heater core out to suction port connection on water pump.

These two recommendations are opposite of each other and I have no idea what to do

Knowing what the ports on your aftermarket water pump are for would help. But really you just need to run a hose from the water passage in the intake to the heater core, and then a return from the core to the radiator or water pump.

here is mine with a carb.

Thank you for the quick responses.

Honestly, I would really like the way you posted in the pix. I want the intake to feed the heater core hot coolant, and warm coolant can go out for the radiator to finish the job of cooling the coolant down.

I think this is safe because there is no possibility for coolant to loop around the head and cause overheating.

My mechanic did my setup a little strange.

The top port of the water pump goes straight to the heater core outlet for warm coolant.

The intake is tee'd together with a tap on top of the water neck, and this together goes to the heater core inlet for hot coolant.

I have no idea why he wanted to tee the intake and the top of the water neck together.

I think I will plug up everything and run it like the pix. Thanks.

More info to add to the pot:

Vintage Air recommends returning coolant to the water pump rather than the radiator. The first part of his comments was directed towards you guys who recommended that I return coolant to the radiator. The second part of his comments was directed towards the Vintage Air recommended way to return coolant to the water pump.


So I don't know what to do now :-(

GM did away with the return to the water pump and added the return on the radiator. Whether the change was due to space limitations or an improved design, it works. If it works good enough for the company liable for all the customer complaints, and warranty repairs, it must work pretty well.

I just got off the phone with an Edelbrock tech and he confirmed Vintage Air's routing.

I hear what you're saying in mind. Since it's cheaper for me to do the Vintage Air way I'll keep it that way for now. If it gets too hot I'll try to go your way.

My heart wants the radiator but my brain wants the water pump

Thanks for the help.

wow gm designs and produces billions of cars. and you are listening to a couple a performance companies. although they are reputable companies i havent see any cars designed by them.

I'm a classically trained engineer so you have to give me more than the manufacturer's ethos.

My drivetrain is pre-85 small block into a kit car. If it were a Camaro drivetrain then I would stick with the stock setup.

The problem for me is there is no "stock" template, although I've been using a lot of third gen stuff to build my kit car. A pre-85 C pickup is probably a better template.

I'm going to call Vintage Air one more time tomorrow and make a final decision.

If you don't have the port in the radiator, I'd use the water pump... If you've got the radiator port, I'd use it. Either way works. I can tell you for a fact, if you run the water line to the radiator, and the other to the water pump, the heater never gets warm. LOL

I don't have a port on the radiator but I have one on the water neck between the thermostat and the radiator. But if it's absolutely the best way, I will install a port on the upper tank of the radiator. It's not a problem.

Makes sense how the coolant is already cold from running through the radiator.

Thanks for your help.

usally its pretty easy it will be a short hose running in and out the angine i think or capped off either way they are differnt sizes aswell the tubes on the heating core so its simple to see which on goes where... well its been that way for my dodge dakota and now camaro