Coolant bleed screws
Discussion
phillpot said:
pmessling said:
I got two blanks drilled the centres tapped them. Then drilled the centre of two bolts half way down cross drilled it to make my own. Hate the original ones.
Sounds like hard work? how about something like this....... 
Or this.......
References please ?
Ta !
I'm a heating engineer, we use 1/4 inch bsp air vent all day.
Might I suggest a automatic airvent from bes, this will automatically bleed itself any air in the system then maintain the pressure of the system.
£4 too.
https://www.bes.co.uk/1-4in-bsp-hygroscopic-automa...
Edited to add:
https://www.toolstation.com/shop/Heating+%26+Insul...
72p in tool station for a key type normal air vent.
All the best
Might I suggest a automatic airvent from bes, this will automatically bleed itself any air in the system then maintain the pressure of the system.
£4 too.
https://www.bes.co.uk/1-4in-bsp-hygroscopic-automa...
Edited to add:
https://www.toolstation.com/shop/Heating+%26+Insul...
72p in tool station for a key type normal air vent.
All the best
Mr Cerbera said:
References please ?
Ebay... search radiator bleed screw or any plumbers merchantBAM225 said:
I'm a heating engineer, we use 1/4 inch bsp air vent all day.
Might I suggest a automatic airvent from bes
Used to buy from BES in my last job, unless things have changed they are strictly trade only? Might I suggest a automatic airvent from bes
spitfire4v8 said:
I said this 20 years ago but it's probably worth repeating ..
people make 2 fundamental errors when filling the cerb with coolant
1) they point the car nose up
2) they touch those coolant pipe bleed screws
Hi Jools people make 2 fundamental errors when filling the cerb with coolant
1) they point the car nose up
2) they touch those coolant pipe bleed screws
You know already that I respect your opinion and have recommended your services
BUT
Given that air rises in liquid and that these bleed screws have been fitted (on the radiator too)
could you please just remind me (only owned my Cerb for 12 years so I missed the first time round)
what your original statement was and the physics basis behind it ?
Ta !
Paul J
(Luxembourg)
ETA
I ask as I have just cleaned the cooling system and am about to refill from empty TONIGHT
The radiator bleed screw is high up, you don't need to raise the nose far (6 inches maybe) before the water in the header tank never reaches the rad bleed screw level. Result is an air pocket in the rad.
Put the car level or better still slightly nose down, the rad bleed screw will be below the level of the water in the header tank.
The coolant rails alongside the head are self bleeding into the header tank whilst the engine is running (and bleed very slowly overnight if the car is nose down.)
The screws can often leak if touched .. so ..
don't touch them, the rails bleed as the engine is run, just top up the header tank as the level falls with the engine running from cold start.
you will have to refilll a couple of times after the next couple of heating/cooling cycles.
Put the car level or better still slightly nose down, the rad bleed screw will be below the level of the water in the header tank.
The coolant rails alongside the head are self bleeding into the header tank whilst the engine is running (and bleed very slowly overnight if the car is nose down.)
The screws can often leak if touched .. so ..
don't touch them, the rails bleed as the engine is run, just top up the header tank as the level falls with the engine running from cold start.
you will have to refilll a couple of times after the next couple of heating/cooling cycles.
spitfire4v8 said:
The radiator bleed screw is high up, you don't need to raise the nose far (6 inches maybe) before the water in the header tank never reaches the rad bleed screw level. Result is an air pocket in the rad.
Put the car level or better still slightly nose down, the rad bleed screw will be below the level of the water in the header tank.
The coolant rails alongside the head are self bleeding into the header tank whilst the engine is running (and bleed very slowly overnight if the car is nose down.)
The screws can often leak if touched .. so ..
don't touch them, the rails bleed as the engine is run, just top up the header tank as the level falls with the engine running from cold start.
you will have to refilll a couple of times after the next couple of heating/cooling cycles.
Thanks Put the car level or better still slightly nose down, the rad bleed screw will be below the level of the water in the header tank.
The coolant rails alongside the head are self bleeding into the header tank whilst the engine is running (and bleed very slowly overnight if the car is nose down.)
The screws can often leak if touched .. so ..
don't touch them, the rails bleed as the engine is run, just top up the header tank as the level falls with the engine running from cold start.
you will have to refilll a couple of times after the next couple of heating/cooling cycles.
You're a STAR ! 
_______________________________
ETA
Sorry to be a Knobhead
BUT
Am I right in assuming that, when the thermostat opens, the hot water enters the Rad from the top pipe, is cooled, and then exits through the bottom ?
Edited by Mr Cerbera on Tuesday 20th March 10:05
Hi All (and especially Jools),
In the process of refilling a completely drained cooling system.
Filled to level of header tank. - Refitted Header Cap. - Run engine to 75 deg.- Allowed Burbling to settle and system to cool. - Removed cap.
Repeated process running engine to 90 deg feeling top hose to ensure thermostat open.
Waited a day. – Removed cap to find coolant still at header tank level.
Kept tank cap off. - Run engine to 80 deg and header tank overflowed.
Question : Do you think this is a reasonable state to get to before I take her out on the road ?
Ta !
Mr. Pisces
In the process of refilling a completely drained cooling system.
Filled to level of header tank. - Refitted Header Cap. - Run engine to 75 deg.- Allowed Burbling to settle and system to cool. - Removed cap.
Repeated process running engine to 90 deg feeling top hose to ensure thermostat open.
Waited a day. – Removed cap to find coolant still at header tank level.
Kept tank cap off. - Run engine to 80 deg and header tank overflowed.
Question : Do you think this is a reasonable state to get to before I take her out on the road ?
Ta !
Mr. Pisces
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