Air lock - The 1947 - Present Chevrolet & GMC Truck Message Board Network

hotrodder · 06-12-2015, 08:35 PM

I have a 327 in my 67, I believe it has a air bubble in the cooling system. How do I go about bleeding the air out? Thanks

1972RedNeck · 06-12-2015, 10:45 PM

I always drill a small hole in my thermostat.

franken · 06-12-2015, 11:26 PM

Drive it. 50 million SBCs were made from '55 to 2000 and nobody drilled a thing. Well...

geezer#99 · 06-13-2015, 09:10 AM

Quote:

Originally Posted by hotrodder

I have a 327 in my 67, I believe it has a air bubble in the cooling system. How do I go about bleeding the air out? Thanks

What makes you think that?
What exactly is it doing?

cdowns · 06-13-2015, 09:18 AM

myth

hotrodder · 06-13-2015, 09:25 AM

I changed the intake, put a new thermostat , started the truck and added water/ antifreeze. It only took about 3/4 gallon. when the motor is running it starts to puke out the overflow and the top radiator feels as if there isn't enough water in it, but the radiator is full,

hotrodder · 06-13-2015, 09:26 AM

I meant to say top radiator hose. Duh!!

geezer#99 · 06-13-2015, 10:02 AM

Quote:

Originally Posted by hotrodder

I changed the intake, put a new thermostat , started the truck and added water/ antifreeze. It only took about 3/4 gallon. when the motor is running it starts to puke out the overflow and the top radiator feels as if there isn't enough water in it, but the radiator is full,

Sounds normal!!
Are you filling the rad right to the top or leaving the level down a couple inches?
If you have a puke hose then leave the level down a couple inches.
If you have a return/catch can then fill it full.
The liquid expands when heated.

MagmaJct · 06-13-2015, 11:58 AM

Quote:

Originally Posted by cdowns

myth

I'd have to say I agree. Because of the pump the coolant in the engine is under higher pressure than the radiator. The engine is filled from the bottom up. The radiator is filled from the top down. The air would tend to accumulate in the low pressure of the radiator, not the high pressure of the engine.

Regards,
Mike

**Jurassic-1** · 06-13-2015, 02:41 PM

Another way to burp it is to put the front end up. Either jack it up or park it on an incline it helps all the air work to the highest point.

GASoline71 · 06-13-2015, 03:24 PM

Quote:

Originally Posted by geezer#99

Sounds normal!!
Are you filling the rad right to the top or leaving the level down a couple inches?
If you have a puke hose then leave the level down a couple inches.
If you have a return/catch can then fill it full.
The liquid expands when heated.

This^^^ 100%

Gary

hotrodder · 06-14-2015, 11:06 AM

I'm going to try the jack up the front thing.I know newer cars have a bleeder valve that can be opened to let the air pass out as you fill them.

geezer#99 · 06-14-2015, 01:00 PM

Quote:

Originally Posted by hotrodder

I'm going to try the jack up the front thing.I know newer cars have a bleeder valve that can be opened to let the air pass out as you fill them.

Some newer ones do!
Do you have a catchcan/overflow bottle or just a hose running to the ground from your rad fill spout.

hotrodder · 06-14-2015, 09:08 PM

Just a overflow hose.

geezer#99 · 06-14-2015, 09:37 PM

Are you filling the rad right full when cold or are you leaving the level down a couple iinches?
Do you have the right rad cap?

06-12-2015, 08:35 PM	#1
hotrodder Registered User Join Date: Oct 2011 Location: Bloomington Indiana Posts: 322	Air lock I have a 327 in my 67, I believe it has a air bubble in the cooling system. How do I go about bleeding the air out? Thanks

06-12-2015, 11:26 PM	#3
franken Registered User Join Date: Jun 2013 Location: Somewhere Posts: 3,068	Re: Air lock Drive it. 50 million SBCs were made from '55 to 2000 and nobody drilled a thing. Well...

06-13-2015, 09:18 AM	#5
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Air lock myth __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

06-13-2015, 09:25 AM	#6
hotrodder Registered User Join Date: Oct 2011 Location: Bloomington Indiana Posts: 322	Re: Air lock I changed the intake, put a new thermostat , started the truck and added water/ antifreeze. It only took about 3/4 gallon. when the motor is running it starts to puke out the overflow and the top radiator feels as if there isn't enough water in it, but the radiator is full,

06-13-2015, 09:26 AM	#7
hotrodder Registered User Join Date: Oct 2011 Location: Bloomington Indiana Posts: 322	Re: Air lock I meant to say top radiator hose. Duh!!

06-13-2015, 02:41 PM	#10
Jurassic-1 Registered User Join Date: Jul 2007 Location: New River Arizona Posts: 1,180	Re: Air lock Another way to burp it is to put the front end up. Either jack it up or park it on an incline it helps all the air work to the highest point.

06-14-2015, 11:06 AM	#12
hotrodder Registered User Join Date: Oct 2011 Location: Bloomington Indiana Posts: 322	Re: Air lock I'm going to try the jack up the front thing.I know newer cars have a bleeder valve that can be opened to let the air pass out as you fill them.

06-14-2015, 09:08 PM	#14
hotrodder Registered User Join Date: Oct 2011 Location: Bloomington Indiana Posts: 322	Re: Air lock Just a overflow hose.

06-14-2015, 09:37 PM	#15
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,542	Re: Air lock Are you filling the rad right full when cold or are you leaving the level down a couple iinches? Do you have the right rad cap?



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