Is it possible to

[stevedon]

I am wondering if it is possible to connect the bleed off outlet pipe from the engine,to the header tank.
I see there is a outlet/inlet on the left of the header tank which could be drilled thru.
If I restricted the pipe flow surely this would not effect it too much but ensure there was no air in the head.
Your thoughts please.

[mikeonb4c]

I am wondering if it is possible to connect the bleed off outlet pipe from the engine,to the header tank.
I see there is a outlet/inlet on the left of the header tank which could be drilled thru.
If I restricted the pipe flow surely this would not effect it too much but ensure there was no air in the head.
Your thoughts please.

Interesting thought. I'm sure there must he some reason why Mazda didn't do it, but i'm not enough of an automative engineer to make the case. Oh, how about this. Since the bleed hose is a dead end then, whether sealed by its bung or by system back pressure when engine is at work, it is not a good route for flushing air bubbles out of the system. Purging to the header tank by the scouring effect of pumped flow is thus the chosen route to go. But I still think you have a point, with the bleed hose being attached to an engine hot spot. Maybe let those with a better understanding join the debate

[Simon Jones]

Been there, tried that and it doesn't work as there is insufficient pressure in the system to force the coolant up to the header tank. You would end up with a pipe full of air which is exactly what you want to avoid. Have a read of this thread to see the bleeding solution that I now use:

http://igmaynard.co.uk/bongo/forum/view ... tive+bleed

Going to make a mk2 version at some point which is more compact and can easily be carried with me in case of emergencies.

[g8dhe]

The 2 litre engine does just that, see the header tank http://lushprojects.com/bongopartsmk2/c ... 02.html#19
it has an extra hose back to the engine. However that has been the design back to the original version so they must have had a reason not to use that technique on the diesel and V6......

[teenmal]

Hi stevedon,you could have a point there,it would be worthwhile checking our the cooling system on the 2litre engine.

Let me know what you think.

[RobEvans]

what about an automatic air vent instead of the bung In the bleed pipe any thoughts. We use them on heating systems up to 3 bar most are tested to 10 bar from industrial suppliers like bss.

[teenmal]

what about an automatic air vent instead of the bung In the bleed pipe any thoughts. We use them on heating systems up to 3 bar most are tested to 10 bar from industrial suppliers like bss.

Hi good idea but would you not need the bleed valve at the source of the trapped air(the bleed pipe is a dead leg)

[the1andonly]

Simon
Having read your thread a few questions,
have you fitted a sight tube?
how do you know when its finished bleeding?
How long does it take?
Ps I haven't attempted to bleed yet so forgive any daft questions
John

[Simon Jones]

Simon
Having read your thread a few questions,
have you fitted a sight tube?
how do you know when its finished bleeding?
How long does it take?
Ps I haven't attempted to bleed yet so forgive any daft questions
John

Not fitted sight tube yet although I have got one with a one way valve for the mk2 version.
Generally run it for a few minutes with the bleed valve open, then close it for a few minute to allow any air to build up and then open it for a few minutes. The coolant coming out the bleed pipe is usually pretty frothy but does settle down after a number of open and close cycles. I usually wait until the thermostat opens to ensure coolant fully circulated. When I last bled it in November, it was pretty cold and dark, so I didn't rev it too much, but I guess the whole lot was done in under half an hour.

Another member on here was doing something similar but on a more industrial scale using a domestic hot water pump which is fine as long as you access to mains power. I must get on with the mk2 version soon as am planning to do some more coolant system work soon. Will post pictures when finally completed.