Vacuum filling coolant 2.7T?

[erykv1]

Hey guys

Have any of you guys vacuum filled our coolant systems before?

Putting the car back together however when I put vacuum on the system it doesn't want to hold vacuum past 15psi. Is our system different to this method or do I have a leak in my system somewhere?

Love to hear some experiences before I try to retrace all my coolant lines.




Thanks!

[Mille Bornes]

I've never done it on our cars but have used the vacuum fill on others. I've seen gauges read incorrectly

Does it hold steady vacuum or leak down?

[discoverdeath]

Honestly the best way to fill the system. That method of filling the cooling system is supposedly mandatory for all 4.0 t cars. I have also found that by using this method it has reduced the chance of getting a air pocket in 1.8t equipped cars.

[S4tech2]

I do it everyday to every Audi I have to drain the coolant out of. IMHO it's the best way to fill the coolant so you aren't waiting for the Tstat to open and then hope you get all the air out.

[tHatOne guY]

Sounds like you have a leak somewhere. Try pressurizing the system to about 16 psi before applying vacuum to make sure you have no leaks.

[S4tech2]

And I use it on my 2.7t also, and it will show a leak before you put coolant in it. So if it shows a leak you can just use water to find the leak, repair it, drain the water out and fill it with coolant.

[erykv1]

Welp. Thank you all for your replies. Looks like my radiator had a crack on the bottom of it. No idea how it happened... Time for a new one.

[zillarob]

Last time I saw one used on an audi, the heater core popped when it got up to op temp
I dont use it unless I am having trouble the old fashioned way. So never on a b5s4.