cooling system ?

[Andy XR8]

changed coolant on the weekend and now the system won't pressurise. i've tryed leaving the cap off, undoing what i think is a bleeder valve, replacing the cap and every time i take it for a drive to heat it up, (it never over heats, doesn't even go near half way just stays in the same place it always did), i can take the cap off like it was cold. please help.
The system is supposed to have pressure in it right?

[InfernoSR]

Originally Posted by Andy XR8

changed coolant on the weekend and now the system won't pressurise. i've tryed leaving the cap off, undoing what i think is a bleeder valve, replacing the cap and every time i take it for a drive to heat it up, (it never over heats, doesn't even go near half way just stays in the same place it always did), i can take the cap off like it was cold. please help.
The system is supposed to have pressure in it right?

Yes.. its meant to have 16psi pressure.

Are you using the correct cap? there could also be a leak somewhere... there are a few things to look for...

[howesy]

Originally Posted by BLUEPRINT

Yes.. its meant to have 16psi pressure.

Are you using the correct cap? there could also be a leak somewhere... there are a few things to look for...

AU's actually run 20psi (CPC replacement part# 522-20)
Same cap from EB through to BA 6 and 8 cyl.

[InfernoSR]

Originally Posted by howesy

AU's actually run 20psi (CPC replacement part# 522-20)
Same cap from EB through to BA 6 and 8 cyl.

Um... the 20 in the part# doesnt denote it to be 20psi... it denotes it to be 120kpa (16psi).

That I know, as i've been in the cooling game for around 10years, and we have 4×E-Series and 1×AU in the family currently... we also sell CPC caps...

[howesy]

Originally Posted by BLUEPRINT

Um... the 20 in the part# doesnt denote it to be 20psi... it denotes it to be 120kpa (16psi).

That I know, as i've been in the cooling game for around 10years, and we have 4×E-Series and 1×AU in the family currently... we also sell CPC caps...

Sorry but My car came from factory with 20psi and here is the link showing the listing and part number. click on the cap at the top to show more detail and the specs will come up.
Ford XR8
Part# 522-20
Blow off pressure 20 psi/ 135Kpa
Short neck depth std type- width 80mm height 22mm


http://www.cpcauto.com.au/radiator_c...?PartNo=522-20

I thought they were 16 myself until I went to replace it and looked closely.The BA runs a different cap again was mistakenly quoted.

[InfernoSR]

Getting some tech documents now from suppliers... will come up the comparisons soon...

[5.0 ED]

Andy xr8 - when you get in your car and start it, it will have no pressure, mine doesn't pressurise until after a probably at least a 20minute drive, if your's isn't building up pressure and isn't leaking coolant anywhere, replace and the cap on the reservoir bottle, its probably just not sealing, clean around the bottle mouth too.

And as for what the cap is rated at, it doesn't mean that the cooling system is supposed to have 16psi in it, it means that the cap will release the pressure at 16psi as a safety net to stop bursting hoses etc. under severe conditions. Normal running temp pressures are far lower, but depend on a lot of other things, like what thermostat is in it, what type of coolant you are running and mixture and the overall condition of your cooling system.

[InfernoSR]

Ok... i give up... 10years specialist experience must not mean much to people these days... I could give you a LONG list that will make you cring and wimper with possible issue's with your cooling system from simply using the wrong type of Inhibator/Conditioner...

[5.0 ED]

Well what is blueprint, is the system suppost to run exactly 16psi cause the cap is a 16psi cap, or is it there to release pressure when it gets over 16psi to protect the cooling system?

Your the specialist teach us the errors of our ways.

[Andy XR8]

as i stated in my original post i already replaced the cap, there is not one leak, it has great flow, and it runs the same temp it always did before i changed the coolant. can anyone tell me why it won't build pressure.
cheers

[5.0 ED]

Ok so what coolant did you put in and how much? And how long are you waiting for pressure to build up and how are you testing it, are you just opening the water bottle and waiting for the shh?

Even though you have replaced the cap it doesn't mean it is sealing.

And just for testing's sake i have just got home from work, drivin some 50km's, and walked outside, my car has been turned off for about 2minutes, and when i opened the bottle, i had no shh from pressure out of my AU v8.

Personally i wouldn't worry about it cause your not losing water, and your temperature is sitting fine.

[InfernoSR]

Originally Posted by 5.0whiteaughia

Even though you have replaced the cap it doesn't mean it is sealing.

I agree there... I always pressure tested the caps before selling them... and have sent MANY back that simply are faulty...

[Andy XR8]

well i drive home from work which is half an hour and as soon as i pull up i leave the car running and take the cap off and it comes off as if the car was cold. i used a 5 litre bottle of nulon concentrate. i had a bit of success tonight though i loosened the cap off and there was a hiss but some coolant came out as well, is that from air trying to escape or something esle, i thought these systems were self bleeding.
cheers

[5.0 ED]

ok with the car running you will have no to very little pressure, the water pump pulls the water and creates a vacuum on the inlet side of the radiator, thus no pressure at bottle, their will be some pressure inside the engine, cause by the water pump forcing it in and the thermostat restricting it at the outlet but at the water bottle no too little pressure, unless its boiling of course.

Also the nulon concentrate has a high boiling point, which i believe would be around 130degree's in your cooling system, it won't get pressure.

So relax and don't worry about it and just drive and enjoy your car.

:

[Andy XR8]

ok i'll relax now thanks for all your help.

[5.0 ED]

No probs.

[EvilChief]

if ur top radiator hose has pressure (firm in feel) its all good

the overflow tanks not always pressurerize to a point where coolant will go everwhere when you release it, in fact fords in general with the integrated coolant reservoir are actually quite good for it. holdens are a diff nightmare all together.