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Bleeding Air From Coolant

eXc

By eXc,
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eXc Mentor

eXc

Posted
Posted (edited)

Hey guys

R32 GTST

Had to replace radiator.

I think I have an air lock

What is the correct way to bleed the system? I think I should have replaced the thermostat aswell, cause the bottom hose doesnt get hot even after a 40 minute drive (i.e. I don't think it's flowing)

All I have done is run the car till it was warm with the rad cap off. I also tried removing the bleed screw on the top of the engine/inlet. Am I supposed to do that hot or cold? While the car is running? When do I put the bolt back in?

Any other ideas? I assume the bottom hose should get hot? How can I tell if it is passing coolant through or not?

Also, where is the drain bolt on the head that I hear people talk about? I can't find it

cheers

Chris

Edited by eXc
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eXc Mentor

eXc

Posted
  • Author
Posted
have you taken the top and bottom hose off the radiator and stick the hose in the top, then turn it on, to see if it flows?

Huh? Put the bottom hose onto the top of the engine? That would put water the wrong way around?

Can you explain in more detail?

eXc Mentor

eXc

Posted
  • Author
Posted (edited)
heh... bottom would stay cold if your waterpump died, right?

No flow and no airbubbles when you leave the cap off... would explain that too.

I get air bubbles from the bleed point, and at the radiator cap...well...I did for a while until it put all the air out...

I still get air bubbles at the bleed point....but I don't know the right way to use it.

Water pump is only ~6000 kms old too

Edited by eXc
RANDY Veteran

RANDY

Posted
Posted

oh cool.

Black32 means:

1) Take out the radiator completely.

2) Stick the garden hose down the top

3) Watch the water flow out the bottom.

Pain in the ass, but if you really suspect a blocked radiator, this will tell you for sure. (and also give you a nice radiator flush)

eXc Mentor

eXc

Posted
  • Author
Posted
oh cool.

Black32 means:

1) Take out the radiator completely.

2) Stick the garden hose down the top

3) Watch the water flow out the bottom.

Pain in the ass, but if you really suspect a blocked radiator, this will tell you for sure. (and also give you a nice radiator flush)

Ok. yeah I did that.

Can anyone tell me how to bleed the system correctly please?

I mean I have been running it for a few days with no dramas so I guess it's all good. But would be nice to check it out.

  • 1 year later...
cogs Experienced

cogs

Posted
Posted

I need help also!

I have an R32 GTST - RB20DET.

I filled it up with coolant, put the radiator cap back on and started the car.

I then fully removed the bleed bolt. I left it idling for around half an hour with heater on full (32'C FAN SPEED #4). I was told to wait until bubbles stop coming out and you just get coolant but it never happened. Got close a few times, but bubbles kept coming up now and again.

I should note that it wasn't a steady stream of bubbles/coolant coming out. It was very intermittent and sometimes you'd see the bubbles/coolant start coming up but then go back down. A lot of air bubbles came out but still never got just coolant to come out.

Radiator is full and overflow is above min.

What am I doing wrong?

tacker Mentor

tacker

Posted
Posted

I think you should run the car, then stop it and allow to cool down. open the radiator cap when cool and open the bleed bolt, i just keep adding coolant as it flows out of the bleed bolt until its a solid stream of coolant then put bolt back in and top raditor and put cap back on.

cogs Experienced

cogs

Posted
Posted

do you guys think my car will be safe to drive???

not much coolant was making its way out of the bleed valve, i would've lost a few mm of depth in radiator after 30mins, thats it.

how long should it take to get all the air out because i had it idling for at least 30mins slowly getting (some of) the air bubbles out but surely it doesn't take that long?

how do i make sure all of the air is out?

benl1981 Grand Master

benl1981

Posted
Posted

I had the same thing. The last time I did it I hardly bothered with the bleed bolt. Just idle it up to operating temp with the bleed bolt almost out and the rad cap open -keep topping up. Take the car for a short drive (with cap and bolt done up). Let it cool..open up bleed screw, then rad cap and add extra.

  • 1 year later...
  • 12 years later...
Swagendubz Newbie

Swagendubz

Posted
Posted

@cogsDo you happen to know exactly where the bleeder screw is? Having issues getting air out of the system on my rb20 and can't find any info on it. Replaced water pump and thermostat and deleted the heater core inside the car and i can't get the system to bleed properly. Trying to hit an event this weekend. 

  • 3 years later...
joshuaho96 Veteran

joshuaho96

Posted
Posted
53 minutes ago, silviaz said:

I read on YouTube that the neo has 2 bleeder valves? Can't see anything in the manual though

Screenshot2025-01-23at8_48_41PM.thumb.png.7e03e5208b2ad237d7e74aa68cb7c641.png

IACV has an air bleed plug in this part of the engine manual. I'm guessing if it isn't bled it will cause weird idle behavior as the cold start valve won't get hot enough to close properly at the usual rate. 

  • Thanks 1
GTSBoy Grand Master

GTSBoy

Posted
Posted
7 minutes ago, joshuaho96 said:

I'm guessing if it isn't bled it will cause weird idle behavior as the cold start valve won't get hot enough to close properly at the usual rate.

Not that anyone in most of Oz would notice if there wasn't coolant flow.

When I bought my Neo, that whole coolant path was completely blocked with solid crap. I had to dig it out so that I could bleed the cooling system properly, but until I did, I never struggled with idle control. We're not in Idaho.

joshuaho96 Veteran

joshuaho96

Posted
Posted
1 hour ago, GTSBoy said:

Not that anyone in most of Oz would notice if there wasn't coolant flow.

When I bought my Neo, that whole coolant path was completely blocked with solid crap. I had to dig it out so that I could bleed the cooling system properly, but until I did, I never struggled with idle control. We're not in Idaho.

Kind of surprising, with cars this old I've seen a lot of them suffer from high idle due to internal vacuum leak. Fuel trims look fine but the cold start valve just wore out from all the heat cycles and won't close up all the way. Rather notorious issue in some models of the Toyota 4Runner: 

 

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