Bongo Fury

Followed the fact sheet for 'changing coolant' by BigDaddyCain in the members area.

The fact sheets suggests that after flushing with warm water,
15 litres of antifreeze/water is required to refill the system. All this is done with the engine running.

However, after only pouring 3 litres of antifreeze/water mix into the header tank, the antifreeze was coming out of the bleeder pipe.

Can anybody advice what has happened. Is this normal or is the antifreeze not flowing around the enire system?

The reason I am changing the antifreeze is due to an ver heating problem. I am hoping it is simply trapped air!!! See following thread if interested - 'Overheating.Not the head gasket - Thankfully. But what next?'.

Any help is much appreciated

You have to hook the bleed pipe into a raised position - sounds like you have it hanging down

HA106420 wrote:Followed the fact sheet for 'changing coolant' by BigDaddyCain in the members area.

The fact sheets suggests that after flushing with warm water,
15 litres of antifreeze/water is required to refill the system. All this is done with the engine running.

However, after only pouring 3 litres of antifreeze/water mix into the header tank, the antifreeze was coming out of the bleeder pipe.

That's quite right,you will see some evidence of the new anti freeze coming from the bleed pipe,but still only in a weak solution till more is added,remember that the engine is running,so pumping coolant (pretty quickly) around the cooling system constantly,when you are happy that you have added an uninterupted amount of coolant,re-bung the bleed pipe,and run to hot with heaters on full,checking level constantly,remember to top up with half a litre of coolant before you re-start the bongo again from cold...(chances are its just above the minimum mark after the bongo has cooled off)

I found this too with bdc's method, with the engine running it's circulating round the system & mixing. Ended up getting it thoroughly bled & burped with clean water with the engine running, then turned off the engine to fill with antifreeze, maintaining header level while emptying from the bleed pipe. if it starts coming through, drain it into a container & then you've got a bit of top up mixed for when the level inevitably drops slightly over the next day or two.

francophile1947 - Have tryed holding the bleed pipe higher then the header tank whilst filling the system (with engine running), but the coolant simply overflowes from the header tank, therefore preventing me from filling the system.

I thought this would be expecetd if the bleed pipe is held higher then the header tank. Is this not the case?

Cheers

francophile1947 wrote:You have to hook the bleed pipe into a raised position - sounds like you have it hanging down

Mine was only a few inches higher than the bleed pipe outlet,and then only as a matter of convenience...

The main principle is letting the smallest amount of air into the sytem in the first place,therefore limiting the chances of an airlock,you won't purge the system of all the air whilst bleeding,that can only occur with regular use of the bongo,and the hot air's nature of rising up to the top of the header tank,and releasing through the headers overflow gradually with regular warm ups/cool downs...

top up the header tank about half way then with engine off
and top of tank off give the top hose a good squeezing
then top up tank again do this till the level stops going
down then leave over night do same in morning then give
it a try it worked on ours and we don't have a bleed hose.
Done 12 months and 8000 miles since then and the temp
gauge as never flinched.
Hope this helps.

PS keep a eye on the temp gauge and listen for the
scavenge fan coming on don't let it get to hot.

With a combination of this and the other methods
you should be able to get even the most stubborn
Bongo bled up and running.

missfixit70 - thats what I thouht prior to reading the fact sheet i.e. to do it with engine not running.

Should I be holding the pipe above or below the header tank?

Thanks for the help everyone. Its fantastic how people reply so quickly with excellent advice!.

HA106420 - have PM'd you

HA106420 wrote:missfixit70 - thats what I thouht prior to reading the fact sheet i.e. to do it with engine not running.

Should I be holding the pipe above or below the header tank?

Thanks for the help everyone. Its fantastic how people reply so quickly with excellent advice!.

If there's two of you, one filling while one draining with the bleed pipe below header at equal rates. If there's only you, fill header to the top, drain a litre or so from the bleed, put the stop back in - top up header again & so on. Check out the see saw bleed method - very satisfying to get the big burp, but it took a day or two & a couple of top ups for all the air to bleed out even after an exhaustive flush & bleed.

I dont usually bleed my own bongos, as usually done at service if I request it. Had one the other day where I could hear a water gurgle as I accelerated so put it down to an air lock. Had to cut the bleed pipe down due to some chaffing, so could not hold it above the expansion tank sufficiently whilst doing this on my own.
Came up with a variation on the funnel method.
I had a 10lt water container with a small tap on the bottom - I supended this from the flipped up passenger seat and pushed the bleed pipe over the open tap.
A few litres in the water bottle plus filled the expansion bottle and reved it up over a 30 minute period. You could see bubbles comming into the water bottle, but as there was a good few inches of water in it there was no chance of reintroducing air into the system. When I saw no more air bubbles I turned the tap off then removed the bleed pipe. On the whole I was quite pleased with this as a one person method.
Only problem - I have to do it again once I replace a few hoses .

I've only ever followed the Factory method on 4 Bongos now and never had to wait several days for burping to happen.
The coolant is added to the vehicle with the engine OFF, then started to bleed.
The whole job including the rigmarole of running at 2500 rpm takes around 45 minutes to get everything air free. And thats it............

Thanks dandywarhol

'The coolant is added to the vehicle with the engine OFF, then started to bleed'.

How do you mean....'then strated to bleed'.

Cheers

.......as per the manual

bleed pipe in situ, higher than the cyl head - bucket below it
fill radiator, refit cap
fill expansion tank (reservior tank) to the flange line - keep cap OFF
turn OFF A/C
idle engine for 10 mins.
run @2500 rpm for 6 mins (I jamb a bit of wood bewtween the throttle stop and arm)
check the lower hose for heating up during that time
coolant/air SHOULD spurt out of the bleed pipe during this period.
if not, keep revs high til it does
keep the expansion tank topped up
attach the bleed pipe bung with the hose pointing UP
replenish coolant to the full mark on the tank

If at any time the engine overheats/cooling fans stay on/steam continously comes out the bleed pipe during this - shut it down immediately!

This whole sequence could take 3 goes - 3's the most I've done.

Keep an eye on the coolant for the next few days

PHEW...........

And much money has been made via mazda/ford dealers in japan from the above method too....

I'm not suggesting it doesn't work, it obviously does, but it sounds like a complicated,daunting task to a non mechanic....

I have been told by a very reliable japanese associate that mazda dealers would charge the equivalent of £100 every two years to owners of bongo's/freda's,otherwise the manufacturer's warranty would be null & void... This was enough to put off any home "mechanics" from such a task,or any non-dealer garages for that matter... I'd call it blackmail personally.

Then, suprise,suprise, how did the techies at mazda do a flush? Two of them with the engine running,using a hosepipe of hot water,with anti-freeze blended in..... Of course, i wasn't there to winess it,so can't confirm it, but it's unusual that a local bongo dealer not a million miles away from myself has used the "hosepipe" method successfully for the last two years,increasingly so recently as "flippa's" hoses have become available,none of the bongo's that have had the hoses replaced,and were bled using the hosepipe method have returned with an airlock.