Another Bleeding Problem

[Jay Gadsby]

The car's a Southern GT40 - 347 - With the "OEM" Southern Header Tank - i/c Bleed Pipe from Radiator to Header.

I'm interested to hear peoples bleeding technique.

How consistent it is.

I'm thinking of getting a vacuum fill system but wanted to know first if this might be a panacea for all woes or not.

I've had success by loosening the higher clips, topping up and systematically tightening the lowest to highest in sequence.

But stiil get an occasional zero reading for a short while when driving which I assume is a small air lock.

Hope some of that makes some sense.

Any recommendations, pointers and techniques welcome.

 

[Randy V]

Vacuum filler will help you eliminate leaks before you spill a drop of coolant.
Vacuum filler, when used properly, will purge all air from the system and replace it with coolant.
Vacuum filler is far less messy than the conventional approaches are.
Vacuum fillers are far less expensive than they used to be since Chinese companies started cloning them. Mine was made by Mac Tools and cost over $200 USD - but worth it. Clones can be found for 1/4 that amount.
—
I wanted to post a “down-side” to Vacuum fillers, but simply can’t think of any…
—
Vacuum Filler for the win, in my opinion….

 

[Jay Gadsby]

Vacuum filler will help you eliminate leaks before you spill a drop of coolant.
Vacuum filler, when used properly, will purge all air from the system and replace it with coolant.
Vacuum filler is far less messy than the conventional approaches are.
Vacuum fillers are far less expensive than they used to be since Chinese companies started cloning them. Mine was made by Mac Tools and cost over $200 USD - but worth it. Clones can be found for 1/4 that amount.
—
I wanted to post a “down-side” to Vacuum fillers, but simply can’t think of any…
—
Vacuum Filler for the win, in my opinion….

Thanks very much for this positive info.

As for the budget clones - It sounds like they are up to the job if used on a sole car and occasionally only.

The premium brands being right for frequent, semi professional / professional use?

 

[Neil]

Vacuum filler will help you eliminate leaks before you spill a drop of coolant.
Vacuum filler, when used properly, will purge all air from the system and replace it with coolant.
Vacuum filler is far less messy than the conventional approaches are.
Vacuum fillers are far less expensive than they used to be since Chinese companies started cloning them. Mine was made by Mac Tools and cost over $200 USD - but worth it. Clones can be found for 1/4 that amount.
—
I wanted to post a “down-side” to Vacuum fillers, but simply can’t think of any…
—
Vacuum Filler for the win, in my opinion….

Collapsing your radiator might be a downside.

 

[Jay Gadsby]

Collapsing your radiator might be a downside.

Any Photos?

 

[Randy V]

Collapsing your radiator might be a downside.

I’ve not had any troubles like that Neil. Collapsed hoses, yes, but they fill up and are good afterwards. Perhaps if you run it on 250 PSI it might, but I regulate my air pressure to 100 PSI and recall that the max pressure spec was something on the order of 150 PSI.

 

[Randy V]

Thanks very much for this positive info.

As for the budget clones - It sounds like they are up to the job if used on a sole car and occasionally only.

The premium brands being right for frequent, semi professional / professional use?

I have not used one of the clones, so really can’t speak with authority on them. I suspect that you are correct. I know mine is high quality and has not let me down in the many years I have owned it.

 

[Bill Kearley]

Air bleeds in the right places, problem solved!

 

[Brian Kissel]

I have a AirLift setup that works excellent. And I also have air bleeds.
All excellent ideas.

Regards Brian

 

[Neil]

I’ve not had any troubles like that Neil. Collapsed hoses, yes, but they fill up and are good afterwards. Perhaps if you run it on 250 PSI it might, but I regulate my air pressure to 100 PSI and recall that the max pressure spec was something on the order of 150 PSI.

Vacuum bleeding is not the same as pressure bleeding. Pulling a vacuum on the cooling system clears out air bubbles but radiators are built to withstand internal pressure and they may collapse under pressure from the outside.

 

[Douglas]

Vacuum bleeding is not the same as pressure bleeding. Pulling a vacuum on the cooling system clears out air bubbles but radiators are built to withstand internal pressure and they may collapse under pressure from the outside.

Neil,

Using coolant vacuum bleeder tools have been automotive, industrial and farm etc standard tools for properly evacuating air from coolant systems for over 25 years. They have never been known to cause damage to radiators or engine parts in the process.

 

[Neil]

Neil,

Using coolant vacuum bleeder tools have been automotive, industrial and farm etc standard tools for properly evacuating air from coolant systems for over 25 years. They have never been known to cause damage to radiators or engine parts in the process.

Yes, but those were not custom aluminum radiators.

 

[Neil]

While we are on the subject of cooling systems, let me caution everyone about a substance that used to be added to coolant as a corrosion inhibitor. In the very early Seventies, we ran a McLaren M8C in the Can-Am Series. Bob Peckham, the owner & driver, always wanted to add sodium dichromate to the cooling water in that car. There were good reasons to do that, in that it ran a big-block aluminum Chevrolet. Leaks were immediately apparent by the bright orange color of that solution. These days, hexavalent chromium is a known carcinogen-- DON'T DO IT!

 

[JP Verweij]

But stiil get an occasional zero reading for a short while when driving which I assume is a small air lock.

That not an airlock.
If a temp gauge reads an air lock (=steam) it should read hot and not cold.
There's no need to purge the cooling system. That airlock should be long gone since you have driven many miles even long distance trips for years.

The electrical system needs attention.

 

[Jay Gadsby]

That not an airlock.
If a temp gauge reads an air lock (=steam) it should read hot and not cold.
There's no need to purge the cooling system. That airlock should be long gone since you have driven many miles even long distance trips for years.

The electrical system needs attention.

Thanks JP

I'll check that through.

 

[Frank Catt]

Jay, there are other important areas to deal with, give me a call if want to discuss, Frank

 

[Randy V]

Vacuum bleeding is not the same as pressure bleeding. Pulling a vacuum on the cooling system clears out air bubbles but radiators are built to withstand internal pressure and they may collapse under pressure from the outside.

The vacuum filler systems use a flow of compressed air through a Bernouli chamber to create a vacuum in the cooling system. You are not pressurizing the cooling system with it.

 

[Neil]

The vacuum filler systems use a flow of compressed air through a Bernouli chamber to create a vacuum in the cooling system. You are not pressurizing the cooling system with it.

OK, I misunderstood the use of the term "pressure bleeding".