Coolng System - Bleedin bleeding

Right some help please

I have replaced a coolant pipe to the rad as it was weeping at the t piece to the heater. I put the front of the car up on ramps and removed the hose, about 1 litre of coolant came out, and the level in the rad was low enough for me to remove the otter switch, apply thread sealinng tape and re install without more than a dribble of collant coming out.

Hoses all reconnected
drive car of the ramps
Jack the rear as high as possible
Start filling the coolant tank, after about third of a litre the haeder tank is full
Go to front of car open rad bleed, aier rushes out until i get a steady flow of coolant - close rad bleed
Top up coolant tank about 1/5th of a litre
Open thrmostat bleed, steady flow
Warm engine until fans cut in (coolant cap on)
Coolant has gone down a bit - top up
Open rad bleed - tiny bit of air then a steady flow
Open thermostat bleed - steady flow
Lower back of car
Short drive to warm back up, gets up to temp, fans kick in heating is working
Check header tank - empty
Undo (slowly) header tank cap, pressure release and some coolant comes back up but header tank not full
Top up header
Raise rear of car
open rad bleed - consant flow
open thermostat bleed - constant flow
Header tank level still as before

I get the feeling there is still air in the system, my guess is tha the hot coolant compressed the air hence emptying the headrer tank and when the cap was released the release of pressure meant that the air pushed some coolant back into the header tanks.

I think that I haven't put in enough coolant so ther emust be air, but both bleeds just flow coolant (coolant doesnt flow from the bleeds when the header tank cap is on, so I think this means that the system is air tight.

Any hints and tips please/advice

I want to use the car tomorrow moring for a 2 hour trip, but dont want to damage it if there is air in the system.

Thanks in advance

I think you've done enough!

They're a pig to totally bleed, sometimes they will, sometimes they won't. My suggestion would just be to go for another drive and top up again if need be.

Sounds like you've got the majority of the air out, but there's such a length to the GTA system (more than any front engined car) that it's inevitable they require a bit more once the systems been churned up a bit.

I'd do that and then take a small bottle of pre-mixed coolant with you tomorrow just in case you find you need to add a bit more -it's mostly just ends and bends harbouring pockets of air, not much more than that. Usually a few run arounds purge the system though so I'd think you should be fine.

I suspect your thermostat has not got a giggle valve or small hole drilled in it....... if there is neither, it won't bleed easily as the thermostat bleed does nothing as it is higher than the closed thermostat and does little to bleed out any trapped air below the stat.
However, as you have driven and the stat has opened, the air should have got passed it hence the level in the reservoir fell. You should be OK now, but do as Darren says, take some coolant with you and check once you have arrived.

Thanks for your help folks

One more question, has anyone increased the length of the radiator bleed tube so it can be taken up into the front boot say next to the winscreen was reservoir? Strikes me that this woul dmke it easier to acess especially with the rear of the car in the air, and it would probably be quicker for the air to escape.

I always bleed the rad(fill system with the bleed open) first i would not do with a with the rear in the air you can easily get to the end of the bleed hose. I don't even stick the rear in the air, run the engine up to temp fit a ring spanner to the bleed nipple on the thermostat housing then fit a long length of hose and with the engine running let it bleed into a container below until it runs constantly. nit the nipple and remove the pipe and take for a short drive, let it cool and top up as necessary...never really had issue tbh works for me every time.

Si21

ps always use a genuine stat as cheap alternatives do not work as they are supposed to, as the large washer at the bottom of the stat seals the engine from the rest of the system and the engine warms up far quicker. As mentioned by John the small 1.5 -2 mm hole works wonders.

Did my 1 hour each way, some spirited driving, some town driving and a traffic jam. All good, engine temp behaving, coolant level constant.

My car has a water cooled turbo that wasn't connected due to a leaky finned pipe in the air duct, so I have fixed said pipe and plumbed it all in. Temp now behaves slightly diferently. When on boost the temp rises faster (still not beyond the mid point) and then drops back to a little below midpoint when I back off.

(at some point I will drill the thermostat)

Did my 1 hour each way, some spirited driving, some town driving and a traffic jam. All good, engine temp behaving, coolant level constant.

My car has a water cooled turbo that wasn't connected due to a leaky finned pipe in the air duct, so I have fixed said pipe and plumbed it all in. Temp now behaves slightly diferently. When on boost the temp rises faster (still not beyond the mid point) and then drops back to a little below midpoint when I back off.

(at some point I will drill the thermostat)

Mine behaves the same ref. temp behaviour.