Coolant Purge

[Stevesas12]

Hi,

Is there a definitive way of bleeding the coolant after a flush?

I've seen so many varied methods, close filler cap, leave filler cap off, close bleed screw, open bleed screw?

Surely the bleed screw is there to actually bleed the air when pump going through cycle?

Thanks

[ayao]

It has been a while since I did this but IIRC all the DIYs that I looked at (at the time) bled via the bleed screw (which apparently is notorious for breaking with old age). The process looked like a total mess with coolant spattering everywhere.

Because of the desire to avoid a mess I ended up getting a Schwaben vacuum coolant purge/flush kit. It was surprisingly mess-free, more or less.

[MightyMouseTech]

We never open the bleed screw (except on the N20's) just take the cap off.

[Stevesas12]

Originally Posted by MightyMouseTech

We never open the bleed screw (except on the N20's) just take the cap off.

I've seen people open the bleed screw only when they are refilling the coolant, & then either leave cap off while pump purging, or with everything closed, cap on while doing the purge.

[MightyMouseTech]

Originally Posted by Stevesas12

I've seen people open the bleed screw only when they are refilling the coolant, & then either leave cap off while pump purging, or with everything closed, cap on while doing the purge.

Just letting you know this is how we do it at the dealer all day every day.

[gjm120]

Originally Posted by MightyMouseTech

Just letting you know this is how we do it at the dealer all day every day.

The cap open is a new one to me. Bentley, and I think TIS, say cap and bleed screw closed

Frankly makes more sense to me to have the cap or bleed screw open so the air has somewhere to escape.

[Stevesas12]

Originally Posted by gjm120

The cap open is a new one to me. Bentley, and I think TIS, say cap and bleed screw closed

Frankly makes more sense to me to have the cap or bleed screw open so the air has somewhere to escape.

Exactly, surely by leaving cap off, the air bubbles can get out. If you bleed air on non electric pump vehicle, then you would leave radiator cap off & warm up engine, watching bubbles come to top & squeezing hoses to help.