Question regard vacuuming the cooling system.

[Elroy the Brave]

I have 2 vehicles that are very difficult to get all of the air out of the cooling system. This manifests itself with the heat not getting very hot...

So I decided to invest in a vacuum cooling system refiller:



Question. Do I need to drain all of the existing coolant out before I vacuum the system? Or will this vacuum out the existing air AND coolant? (not sure if it is strong enough to vacuum out the liquid in the system).

Thanks.

 

[Astro14]

You don’t need to remove all the coolant. Leave what is in there alone.

It will vacuum out just the air. Even a perfect vacuum will not cause coolant to boil off.

If the level is high enough that fluid hits the Venturi - you will get foam/liquid because the liquid itself is being sucked out. But the vacuum system won’t vaporize liquid in the bottom of the block or radiator.

 

[atikovi]

That tool eliminates air in the system, not liquid. If you are changing coolant it would be good to flush the old coolant out with water first.

 

[The Critic]

The system needs to be mostly empty before the tool will work. Otherwise you will get a lot of coolant discharge during the vacuum process. The tool is intended to vacuum out the air and simultaneously assist with refilling.

 

[JimPghPA]

Amazon sells a radiator filling funnel system that would probably do a good job of allowing you to run the engine for a few minutes to get the air out with the funnel installed and half filled so it replaces air with antifreeze.

 

[Chris142]

We had one of those vacuum fillers at the radiator shop. I never used it. The above mentioned funnel worked every time.

 

[Elroy the Brave]

We had one of those vacuum fillers at the radiator shop. I never used it. The above mentioned funnel worked every time.

Must be a Ford Problem:

 

[Astro14]

We had one of those vacuum fillers at the radiator shop. I never used it. The above mentioned funnel worked every time.

The above mentioned funnel would absolutely not work on my Mercedes secondary cooling system. There is not enough volume, and it doesn't get hot while idling, only under full boost. So, you can't bleed it using thermal expansion. You must vacuum out the air, though Mercedes' system is a complex thing involving a funnel like that, venturi vacuum pump and two lines to the schrader bleed valves on the top of the intercooler, the vacuum venturi like the OP bought works fine. Intercooler performance is severely compromised with air in the system, which degrades engine performance. The ECM will pull the timing and boost when IATs exceed a certain threshold.

So, TL;DR - some cars need the vacuum. The funnel won't work.

 

[Chris142]

The above mentioned funnel would absolutely not work on my Mercedes secondary cooling system. There is not enough volume, and it doesn't get hot while idling, only under full boost. So, you can't bleed it using thermal expansion. You must vacuum out the air, though Mercedes' system is a complex thing involving a funnel like that, venturi vacuum pump and two lines to the schrader bleed valves on the top of the intercooler, the vacuum venturi like the OP bought works fine. Intercooler performance is severely compromised with air in the system, which degrades engine performance. The ECM will pull the timing and boost when IATs exceed a certain threshold.

So, TL;DR - some cars need the vacuum. The funnel won't work.

I believe you. We refused to work on European cars as we were not set up for them or properly trained.

 

[doublebase]

Amazon sells a radiator filling funnel system that would probably do a good job of allowing you to run the engine for a few minutes to get the air out with the funnel installed and half filled so it replaces air with antifreeze.

We have one of these, they’re great. Been using these things for 15 years.

The vacuum system the OP is asking about looks interesting.

I have a coolant exchange machine...probably spent $3,000 for it. Used it for a year, now it just sits there...it’s a royal pain to use and no one ever seems to know how to use it right (depending on what type of vehicle you’re working on).

 

[The Critic]

I believe you. We refused to work on European cars as we were not set up for them or properly trained.

Euro cars are not the only ones that require vacuum filling now. I recognize that you may not work on as many newer (1-5 year old vehicles) as some other shops, but vacuum filling is becoming more of a requirement than a suggestion.

 

[Chris142]

Euro cars are not the only ones that require vacuum filling now. I recognize that you may not work on as many newer (1-5 year old vehicles) as some other shops, but vacuum filling is becoming more of a requirement than a suggestion.

We did not see that new vehicles. The stuff we saw was usually 15+ yrs old. A dealer is more likely to see those new cars. Not a hole in the wall shop.