Bleeding heater during install?

[TheHubbardBus]

We're getting ready to put our driver-side heater back in (the only heater in the bus). I was wondering if there's anything special that can/should be done to get all the air out. There are two points of concern for me: The heater itself, and the high point in the lines running to it.

1) The heater: Should I bench bleed / prefill this before installing it? Put it in dry? Does it matter?

2) The hoses: The hoses make a pretty steep ascent up to the point where they enter through the firewall, then from there a mild descent to the point where they connect to the valves in the engine compartment. So there's a high-point in these heater hoses at the exact point where they enter through the firewall. Is this anything I need to concern myself with? It's not the high-point in the system, obviously (the coolant reservoir / degas tank is). But it is a peak in the hoses themselves.

Thanks. Probably stupid questions, but the last stupid question I asked without waiting for an answer on bit me. Any help would be very much appreciated.

[magnakansas]

Did you run across any metal fittings that had little bleeder screws? I have see on the firewall metal fittings in the heater lines that had bleeder ports, they were intended to be finger screws, but were stuck shut. I had to crack them loose with pliers. Are the hoses higher up than radiator/degas tank?

Can you add coolant mixture to the engine and have one hose disconnected until you get coolant ?

My bluebird owners manual lists bleeding the heater system as part of the once a year maintenance list.


William

[TheHubbardBus]

No, no bleeder screws. I have yet to install the heater hoses, and one of the things I was considering was adding fittings with bleeders right at the high point in these hoses where they enter the firewall. But I dunno... no other fittings anywhere to bleed from easily.

[cadillackid]

I do have some bleeder screws.. however what I did was open the valves.. installed the heater dry.. took off the radiator cap and turned on the booster pump with the engine Off.. that filled the whole system up.. I add coolant as needed till it reached the top and left the pump run cap off for 15 minutes or so.. then shut it off.. it seemed to do nicely this way.. my bleeder screw never really hissed at all..



I also have mine set up for 'recovery" where it can expand and then suck coolant back in so when air gets blown out it sucks coolant back in and not air..

[TheHubbardBus]

Yeah, no booster pump here. One & only heater was this one.

[TheHubbardBus]

I'm thinking about getting an airlift-type vacuum bleeder/filler instead of worrying about adding bleeder valves. I'm finding out finding anything radiator / heater-hose related in terms of fittings for 1" hose is almost impossible (everything around it, just not 1").

Any input on this type of tool for / against? If I understand things correctly high points in the system won't matter anymore. Is there any concern with causing damage to anything by drawing a vacuum on it?

[magnakansas]

I have found 1” fittings at the school bus parts places online. An assortment of elbows, tees, straight Y More than one with bleed ports.

Hope this helps. They also have booster pumps. That one thing I don’t buy salvage.

William

[TheHubbardBus]

Originally Posted by magnakansas

I have found 1” fittings at the school bus parts places online. An assortment of elbows, tees, straight Y More than one with bleed ports.

Hope this helps. They also have booster pumps. That one thing I don’t buy salvage.

William

That helps a lot! Thanks William!