Bongo Fury

This is just a theory!

I was doing some plumbing at home the other day and fitted a automatic bleed valve that cost less than a tenner to cure a annoying air lock problem with my heating system, whith in 5 minutes, no more airlocks!!

How about when needing to bleed your Bongo, fit one of these to the bleed pipe just for a hour or so whilst getting the air out.

These little gadgets can take high temp & pressure and they let only air out.

You do need to make sure it vertical when using it!!

Any way there you go, give it a bash

Hmmm good idea !


GJA

Hmmm, I'm not sure. Fine in a domestic plumbing system - because it's not a critical cooling system. But in a vehicle engine, the whole point is to get the air out DURING filling rather than afterwards - so that when you run the engine there's only coolant in the system, not air. If a large air bubble gets circulated to the head of a hot engine then it will very quickly cause gasket/head damage. So I'm not sure that bleeding air out during use would be a safe and viable option. The best course of action is to make sure that all air is bled out during filling - this shouldn't be too problematic even in a Bongo if the correct procedure is followed.

Happy to be shouted down though.....

tigger

When you fill the system with cold coolant your bound to get a bit of air her and there, same as in a domestic system, but when you heat the water it expands and usually you get a little burble or two.

The idea was just to leave the bleed valve on the engine until it warms up whilst following the proper mazda method, your probably find you get that last bit of air out

plus you can do it with one person with this method because the valve will not let any water past it

Yes could do with bleeding valves on those rear radiators to get the air out.

when i wrote "The idea was just to leave the bleed valve on the engine until it warms up whilst following the proper mazda method, your probably find you get that last bit of air out "

i ment put it on the proper bleed pipe under the passanger seat

when i write stuff i just assume people know what i mean

When I bleed mine bongo, the escaping air and coolant comes out under great pressure, so I am not sure the valve idea is suitable in my case, it may restrict the escaping air from giving that large satisfying burp I fit a funnel on the end of the bleed pipe and see-saw it up and down to assist the removal of wind, bit like burping a baby, but on a larger, hotter scale

I have refilled my coolant, and the biggest problem was the lower radiator hose, there was a definate airlock, and the water would not circulate below the top half of the radiator. Below was cold, the lower radiator hose must be hot, then you know you have done it properly. With the engine off, you can squeeze the top radiator pipe and hear water sloshing around, that when you know the system hasn't been bled properly. I follow the NZ repair manuals instructions, and I couldn't have done it properly with out them, you need to run the engine at the specified RPM for the time they say, and then the bleed pipe spits out air and water right on que !
I actually couldn't get it right the first time, and I thought the radiator fans were going for a long time, and thought it could overheat, so I quit for that night, left it parked out overnight to cool, and then had another go the next day.

That completely sums it up Tim.....any othe way and you're asking for trouble.
If the air bleed valves were needed flashg69, then Mazda would've fitted them as standard

Well I bled mine without all the high revs, I live in a built up area and did not want to upset my neighbours

by using the bleed valve the only difference in the bleeding process would be that the bongo would not be spitting out hot water, only air

also dont forget that you would not leave it on the engine permanantly, just while your bleeding it

While there is some logic in the auto air vent suggestion, it would only
work if the bleed pipe rose continuously upwards from the cylinder head.
If there was a downwards loop, it would eventually fill with enough water
to fill the float chamber; which would stop the float from dropping to
release the air. Air will not travel downwards if the pressure either side
of it is equal. In reality, you would need to connect the air vent directly
to the cylinder head with a pipe bend.

When I re-fill the cooling system I extend the bleed pipe using a plastic
barbed connector and an old washing machine hose, this I poke through
the passenger window and wind the window up to trap it some 2 feet
above the water tank.

I can then pour water into the system without having to worry about
getting the carpets, or myself, soaking wet. When the system won't
take any more water, I start the engine and run it at tickover for
several minutes without the tank cap, and add more water if the tank
level goes down.

During this time I can quite easily feel the temperatures at the cylinder
head and pipes from the drivers side and keep my eye on the tank
level, when I'm satisfied that water is circulating through the head
I then give it a few revs and watch the end of the bleed pipe for any
air, usually accompanied with a spurt of water. I try to do this when
the wife (gawd bless 'er) is standing in exactly the right position.
My excuse is that it's usually me that's getting an ear full.

When I drain the system I always mean to measure the amount of
water I take out; so that I can always ensure that I put in at least the
same amount, but in th 4 or 5 times I've done it I always manage to
forget about it, so I would be obliged if anyone knows the exact
amount.

I am just a bit puzzled as to why you have found it necessary to refill/bleed the coolant system four or five times.

Perhaps like me grumpo has had hose problems, hence the number of coolant bleeding episodes

I found the next day when I went back and checked the coolant again, , it must have sucked all the overflow bottle contents back into the radiator,during cooling down (800ml) . I ran it again till it warmed up, then left it another 5 hours, came back, checked it, and it took another 800ml to fill up to the full mark again. The level hasn't dropped again, so I think thats all the airlocks gone. Shows you how easy it would be to overheat and cook the engine, if you are missing over 1.5 l of water out of 7L ?

Timnz wrote:I have refilled my coolant, and the biggest problem was the lower radiator hose, there was a definate airlock, and the water would not circulate below the top half of the radiator. Below was cold, the lower radiator hose must be hot, then you know you have done it properly. With the engine off, you can squeeze the top radiator pipe and hear water sloshing around, that when you know the system hasn't been bled properly. I follow the NZ repair manuals instructions, and I couldn't have done it properly with out them, you need to run the engine at the specified RPM for the time they say, and then the bleed pipe spits out air and water right on que !
I actually couldn't get it right the first time, and I thought the radiator fans were going for a long time, and thought it could overheat, so I quit for that night, left it parked out overnight to cool, and then had another go the next day.