Cabin heater plumbing?

[PeterAllen]

Not sure how many of you run a cabin heater but I've installed a Vintage Air system and I'm just about to do the the hoses for the heater. The proposed routing involves considerable 'rises' and 'falls'.

Am I correct in assuming that, like a garden hose, as long as it is an even 5/8" bore there shouldn't be issues with air pockets? Basically, should the initial air get pushed out of the system and into the motor (LS1) where it's vented normally to the radiator and overflow tank? Thanks.

[albanycobra]

Try and keep the core lower than the bleeder or header tank. Should purge out ok .

[1795]

When I installed my heater I kept the lines relatively tight and did not have any problems with air pockets. You could try leaving the ends of the hoses unhooked where they attach to the block and fill one hose with coolant until it flows out of the other side, then pinch off the hoses and attach them to the engine. Takes two to three people to do it this way and you will spill a little bit of coolant that will have to be cleaned up. Either way, to be safe, leave the cap off of the purge tank when you start the engine so that air can bleed out.

[boxhead]

You want to be sure no parts of the hoses are higher than the radiator cap.
Unless you have installed a higher bleed point.

[PeterAllen]

Part of the hose will be, that's part of my concern. I was hoping that a once it was initially purged of air, water flow would remove any later accumulated air as there are no cavities as in a head or block.

[albanycobra]

I had a problem like that with one of my GT40s it never bleed up properly, I ended up trying a Davies Craig heater hose booster pump. Plumb it line at the lowest pump and it basically forced the water through. No troubles after that.

[PeterAllen]

You have given me cause for concern so I'm now going to route it around the engine to ensure none of the hose is above the engine air bleed point.

Here is a photo of the donor car and it shows the hoses rising from the engine outlet level to a higher heater core, but not above the engine air bleed outlet. I figure if I mimic that set-up I should be okay. Thanks for the posts.

[boxhead]

Early VN Commodore suffered the same thing.
Holden made a radiator extension for bleeding out.
But there was a bleed screw at the highest point (top of thermostat cover)

This is an aftermarket style filler extension.
Coolant Filling Tool SET KIT Filler System Trade Quality Free Express Shipping | eBay

If you have room maybe you can fit this?
Easy Bleeder Cooling System AIR Bleeding System Fits 5 8" Heater Core Hose | eBay