Sucking coolant into cooling system via vacuum

Scott & Heather · February 25, 2020, 04:48:10 AM

I am very painfully aware of how long it takes to burp a dry cooling system on an 8v92 powered bus with twin rads. Took me three days of driving to do it last time. So, can I use a shop vac to somehow pull a vacuum on the cooling system from the fill hatch and draw coolant in via the lower coolant cross line?

richard5933 · February 25, 2020, 05:04:16 AM

Are there any unused ports in the upper areas of the cooling system where you can install petcocks to burp the air out?

lostagain · February 25, 2020, 07:19:18 AM

Fill and purge as much as you can. Then drive and top up as needed. Yes it takes several days.

JC

luvrbus · February 25, 2020, 07:47:18 AM

I bleed the cross over pipe and the oil cooler on the engine and leave a hose loose on passengers side radiator if they don't have a port to purge the system on the upper piping but most do have a port with a plug you can never remove.The coolant path on a 8v92 is from the radiator on the drivers side through the water pump to the oil cooler through the engine to the passengers side and out, follow the path and they are not hard to bleed the air

Jim Blackwood · February 25, 2020, 08:11:05 AM

The answer to the original question is, probably not. Water is pretty heavy and antifreeze is most likely more so. Your shop vac most likely would do very well indeed to pull water up 3 ft. But if you have it full within 3 feet of the top it's possible it could work. How's that for a really ambiguous answer?

Jim

Jim Eh. · February 26, 2020, 08:57:06 AM

Back in the 80s, some automotive applications had printed factory procedures that required applying vacuum to the coolant system to remove the airlocks (Boxbody Thunderbird was an example). As long as your vacuum source doesn't actually withdraw coolant from your point of connection (you may have to install a simple bleed valve to control the amount of vacuum in the system) I cannot see why it would not purge air from the coolant system. Some household vacuums have slide valves that open to atmosphere.

buswarrior · February 26, 2020, 10:39:26 AM

Vacuum cleaner will leave you wanting.

Fooled around more than enough with boat bilges and water pump systems and shop vacs.

The vacuum cleaner won't lift anything worthwhile, except your tears off the floor for wasting your time.

Happy coaching!
Buswarrior

bobofthenorth · February 27, 2020, 05:09:11 AM

I use an old shop vac to pump out the septic holding tank on my current boat. It doesn't take much of a vac to lift 4 feet if you have a decent seal so I have no doubt it would easily draw coolant into a block. Whether that would purge pockets of air is another question.

luvrbus · February 27, 2020, 05:26:11 AM

Scott doesn't have the problem now all the coolant is going into the pan,I hope the seller makes it good for him he is a nice trusting young man he is discouraged but takes it in stride like it is a part of life lol it would be different with me for sure

lvmci · February 27, 2020, 08:26:23 AM

Clifford, is that why the passenger side of the engine is always hotter than the drivers side? tom...

DKO · February 27, 2020, 08:31:46 AM

Does that mean his new engine is no good, Clifford?

Davy

Jriddle · February 27, 2020, 10:45:06 AM

I might not be the smartest person

. I tried to replace a sensor while holding a vacuum on my 6V92. Needless to say I took a bath by being lazy and not draining the system.

John

DoubleEagle · February 27, 2020, 11:54:07 AM

Quote from: Jriddle on February 27, 2020, 10:45:06 AM
I might not be the smartest person . I tried to replace a sensor while holding a vacuum on my 6V92. Needless to say I took a bath by being lazy and not draining the system.

John

But if it had worked, you could have had the procedure named after you!

DoubleEagle · February 27, 2020, 12:01:00 PM

Quote from: luvrbus on February 27, 2020, 05:26:11 AM
Scott doesn't have the problem now all the coolant is going into the pan,I hope the seller makes it good for him he is a nice trusting young man he is discouraged but takes it in stride like it is a part of life lol it would be different with me for sure

Do you know where the leak is at this point? I wonder if there is a possibility that the lines running to the compressor were crossed? He did say he had an unmarked line that he was hunting for a place to connect. Is this turning out to be a disaster of biblical proportions?

Jriddle · February 27, 2020, 12:33:10 PM

Quote from: DoubleEagle on February 27, 2020, 11:54:07 AM
But if it had worked, you could have had the procedure named after you!

The wife's prize Rose Bush near by didn't die thank god or I have been renamed also.

John