Coolant Air Bleed from Heater Loop

[lpmagruder]

Has anyone tried to bleed air from the heater loop instead of the VCP location?

I unfortunately didn't find out about the VCP mod until I had an assembled and running car, and at this point I've had to crack the cooling system open twice and re-bleed. After doing it the first time, I can get it done pretty quickly now (at least quickly enough to make me question if the amount of disassembly needed to do the mod would be worth it)

But, I noticed the top pipe of the heater loop which you put that "u" piece on is connected to the same manifold that the VCP mod is done to. Has anyone tried running a longer loop upwards to a "T" or one of those air bleeder valves? Seems like it should easily catch that air pocket, especially if the back of the car was slightly elevated.

[Bob_n_Cincy]

Has anyone tried to bleed air from the heater loop instead of the VCP location?

I unfortunately didn't find out about the VCP mod until I had an assembled and running car, and at this point I've had to crack the cooling system open twice and re-bleed. After doing it the first time, I can get it done pretty quickly now (at least quickly enough to make me question if the amount of disassembly needed to do the mod would be worth it)

But, I noticed the top pipe of the heater loop which you put that "u" piece on is connected to the same manifold that the VCP mod is done to. Has anyone tried running a longer loop upwards to a "T" or one of those air bleeder valves? Seems like it should easily catch that air pocket, especially if the back of the car was slightly elevated.

Instead of drilling and taping the coolant pipe, I added this fitting.
bobs mod.jpg

[lpmagruder]

Hm, may just be strange camera angle but it looks like your coolant outlet angles right a fair bit?

I have a 07 2.5 turbo motor and it seems to go straight forward to the firewall. I ended up routing it straight down from there to the flexi pipe, which is looking like another mistake I've made!

I've got it bled for now, so I'm not in a rush. Next time I have the system open though it may be worth me taking off all the flexi pipe and re-routing similar to yours with some 90 elbows and straight sections.

[Bob_n_Cincy]

Hm, may just be strange camera angle but it looks like your coolant outlet angles right a fair bit?

I have a 07 2.5 turbo motor and it seems to go straight forward to the firewall. I ended up routing it straight down from there to the flexi pipe, which is looking like another mistake I've made!

I've got it bled for now, so I'm not in a rush. Next time I have the system open though it may be worth me taking off all the flexi pipe and re-routing similar to yours with some 90 elbows and straight sections.

here is a picture of my coolant pipe . out of an 04 forester xt (2.5L turbo). tube.jpg

[lpmagruder]

Hey Bob,

Took your advice and made a similar change to my coolant outlet. Thanks for the advice!

PXL_20230715_215950343.jpgPXL_20230715_215944857.jpgPXL_20230715_201129808.jpg

[Ajzride]

One thing I'll note is that I couldn't get mine bled at idle, I had to rev it up to about 2500 to get enough pressure through the water pump to bleed the heater core.

[lpmagruder]

Yep, I've been running it for a few minutes with the cap off, having a helper hold the RPMs up while I squeeze the top tube a few times. Once it wouldn't take more, ran it around the block a few times, let it cool and topped off a little bit more.

This was a dream, the last 2 times I had the system open, bleeding it was this dance of alternating elevating both ends of the car, squeezing hoses all over, and adding what seemed like teaspoons at a time. With the mod I had it bled in 15 minutes and it was ready to drive!