Ford Lehman automatic manifold bleed

I have been working on running down a leak in my coolant system. When removing the heat exchanger hose from my hot water tank, it felt moist and crumbled in my hand. So I think I found the leak. I bought 50' of heater hose and replaced everything in the system.

But I had put coolant in and topped it off several times during the fix. Each time I had to remember to open the pet cock on the manifold and bleed out the air so that I could get a better read on whether I was losing coolant. Then I thought of the automatic bleeder that I have on the hydronic floor heat in my house. It is the same thing that is used on radiator heating systems in old buildings. It automatically burps out the air but not the liquid. They make them that are okay with glycol antifreeze and can handle way more pressure than the FL will ever make. It even looks like it might be the same size and thread as my petcock. Anybody using one of these to automatically eliminate the possibility of a big bubble in the FL manifold?

https://www.amazon.com/dp/B000MINF3...colid=Q5XMA49EDB8L&psc=1&ref_=lv_ov_lig_dp_it

Mark

Yes. its a float with a needle valve. I don't see any reason why it wouldn't work, but it would also add a failure point. I have personally seen those fail both closed (wouldn't vent) and open (leaking a lot). I suppose once you're satisfied that the air is out of the system you could close it.

Ken

I don't think I would add one to my engine. There is no manual over ride on them. Of course you could remove it when you want to bleed the system after any significant coolant loss. But remember that manifold is cast iron. After a certain number of times removing a fitting you are just about assured you will get it cross threaded or strip it out.

pete

If you added one to your system you could add a ball valve to make it possible to isolate it if it should fail. But then I've become a bit paranoid about redundancy.


Star

Many engines have vent lines from high spots in the cooling system, the vent lines lead to the expansion tank. No valves used. Cummins B and C, Cat 3208T, TA, etc.

I would not trust any automatic valve. They fail and consequences of such a failure can be high. Either bleed manually or connect a bleed line to head tank. I would recommend leave it as-is and bleed manually.

I open the bleed petcock on my FL 120 about once a week while cruising. A little bit of air comes out each time. Bleeding is not difficult so I see no need for an automatic bleeder.

I'm not sure where the air comes from. I pressure test the cooling test once a year and there are no leaks.

My old Cummins V8 has vent lines from the high spots on the mfld. to the thermostat housings. They are just 1/4" OD steel or copper tubes. THey allow escape of any air buildup from filling without the worries of bubbles getting trapped.

Take a good hard look at your manifold and the heat exchanger or the thermostat housing to see if there are any unused ports that could be adapted to install a permanent vent line. The lines do NOT need to be big.