Vacuum Bleeding

[dave_aber]

Don't all throw things at once!

I'm considering trying a vacuum bleed / purge / fill kit when I do my rad and stat swap. One like this.

Only trouble (apart from the question will it do a full fill with no air pockets, or will I still need a funnel & bleed pipe type bleed) is that the kit has a 36mm bung, and the Bongo has a 32mm neck in the expansion tank.

So, fellow bongonaughts;

Has anyone out there used a kit like this to fill a Bongo coolant system?

Did it work without further bleeding?

Did it work, but need further bleeding?

How did you get the kit to fit - is there a 'filler neck expander adaptor' available?

Cheers
Dave

[Northern Bongolow]

never used one dave, nor do i ever intend to.
reasons, in my opinion.
they do nothing to test the system as you fill it, (fans/stat), as they rely on vac to fill the system, it could be filled with a blocked rad, or a blocked heater, as it will just suck in coolant from the other direction, or larger bore pipes.
things like the cylinder head top, the top of each heater matrix cannot be vac purged (air locked) so could end up dry,and how would you know,run it round the block maybe to shift it .

not trying to push the 3 vids again but when using this method certain things happen at certain times.
stat opens, heaters get hot, bottom hose gets hot, fans on, etc, all these are guides to how its going before its run in anger later. they leak more under pressure than they do under vac.
how many times have we heard---- i picked up my bongo today and got 3 miles down the road and---------

but i would say this wouldnt i .

anyone tryed to fill a bongo using the little air bleed nipple on the 1st steel pipe out from the cylinder head yet.

[Bogmonster40]

If anyone in south wales is planning a coolant change in the next few weeks i would love to pop along and watch to see if it is something i could safely tackle.

[dandywarhol]

Only ever used the factory manual procedure - worked every time

[The Great Pretender]

I also have had no problems bleeding, but have also passed air after into the degassing tank over the next week or so.
We have our air con system evacuated and refilled using a vacuum, maybe we don't consider air in the cooling system with the same priority as keeping cool.

[dave_aber]

I agree with your point Ady that vac filling doesn't have the advantage of a built-in stage by stage test of the cooling system elements - I'd not thought about that factor, and it's a pretty relevant one!

things like the cylinder head top, the top of each heater matrix cannot be vac purged (air locked) so could end up dry,and how would you know

Don't agree with this though - the whole point of a vac refill is that the potential airlock points, high spots in the head and matrices etc have the air removed. When you introduce the coolant, it is lifted all the way into these areas since there is no air to lock them. Now, I am talking about a "perfect vacuum" here, and I do understand that the chances of achieving this are nil in practice. There will always be some air in the fully vac'd system before the coolant is drawn in. Which is why I have asked the questions.

I'm also conscious that the system is more likely to leak under pressure than vac. In addition, the system is designed to stand at least 1.1Bar positive pressure, most likely a good amount more - but is it designed to handle the stress of a vacuum? No idea.

Hence the questions.

I've watched the 3 videos a good few times, almost work perfect on them now! Just exploring the possibility that there may be an alternative method.

DA

[teenmal]

Only ever used the factory manual procedure - worked every time

It probably takes longer to do it that way than it takes to assemble (make)the vehicle.?

[dandywarhol]

Only ever used the factory manual procedure - worked every time

It probably takes longer to do it that way than it takes to assemble (make)the vehicle.?

One advantage of a vaccum system would be to eliminate possible leaks - that's what happens when air con gas is removed - the system has to withstand a vacuum to ensure it's gastight otherwise there's no point in replenishing it (although I've a slight leak in a Mazda 6 but it's still working fine 6 months after it was recharged )

[teenmal]

Only ever used the factory manual procedure - worked every time

It probably takes longer to do it that way than it takes to assemble (make)the vehicle.?

One advantage of a vaccum system would be to eliminate possible leaks - that's what happens when air con gas is removed - the system has to withstand a vacuum to ensure it's gastight otherwise there's no point in replenishing it (although I've a slight leak in a Mazda 6 but it's still working fine 6 months after it was recharged )

I can imagine an army of wee Japanese guys at the end of the production line,up to their eyes in Bongos,and up to their knees in antifreeze.

[Alacrity]

Well I have used a vacuum bleeder 3 times when refilling my Bongos, never ever had an issue & it is so so simple. This is how manufacturers fill cars on the production line, they have to do it as quickly as possible without wasting time & coolant. Used correctly it is a simple safe system that also checks the system for leaks before you start. They are used all the time in the trade. Bongos have a cooling system that isn't 'conventional' - but so do a lot of vehicles these days, hence these tools have been developed for the aftermarket. They are for use on exactly the sort of system e Bongo has.

[mikexgough]

Well I have used a vacuum bleeder 3 times when refilling my Bongos, never ever had an issue & it is so so simple. This is how manufacturers fill cars on the production line, they have to do it as quickly as possible without wasting time & coolant. Used correctly it is a simple safe system that also checks the system for leaks before you start. They are used all the time in the trade. Bongos have a cooling system that isn't 'conventional' - but so do a lot of vehicles these days, hence these tools have been developed for the aftermarket. They are for use on exactly the sort of system e Bongo has.

very true.... mass manufacturers always use Vacuum bleeding these days and most new cars are with equipped "fill for life" coolants (11 yr types)....
I bleed my way....which I have found to be the one used by Team MHO engineering in Japan... just a coincidence there but I stick my hands up and I have recently purchased a Vacuum Kit for compressor use and another manual kit for mobile use which does the same job...sucks out into one tank and refills with another tank...

Most of my cars are older type systems with the thermostat on the head exit to top hose rather than the more modern type on the return side of the circuit(like the Bongo)

[Northern Bongolow]

a

[dave_aber]

Well, I went and bought the kit and used it at the start of the week. Swapped the rad and the stat. Reconnected / resealed everything, and used the vac filling kit (It isn't really accurate to call it a vac bleed kit, as it doesn't bleed anything).

So, first of all I had a concern that the kit standard bung was too big to fit the Bongo tank. It isn't. Fits in fine. You do have to block off the overflow pipe though.

So, pumped it down to a good vacuum, and left it for 10 mins. No leaks. Then swapped the venturi block for a filling pipe which I'd sucked concentrated coolant up almost to the top. Open the valve, and in went 5 litres of coolant. Topped up the new coolant bottle with a further litre before it got too low (don't want to suck air in!).

Then added approx. 5 or 6 litres of water to the bottle, whilst the van was sucking in the last of the concentrated coolant. It took around 11-12 litres in total, so obviously some of the old stuff was left behind. I think I'll do another drain / refill soon to make sure I don't have any "mixed coolants" issues.

Ran the engine, and within a couple of mins both heaters were blowing warm. Once the (modified) gauge started to move, both were blowing hot. So far, so good. 10 - 20 mins or so of revving and idling, and the stat opened, bottom hose properly hot too.

Had to go out, so left it at that for the night. Next morning - coolant level fine. Ran up to over 82° with no issues, both heaters and the bottom hose plenty hot.

Went for a wee spin on the road, and everything behaved. Since then it's done a 400 mile round trip to Edinburgh.

So to answer my initial questions - Yes, it can be done, and without further bleeding. And the kits yo can get do fit a Bongo.

Of course, the usual disclaimers apply - The cost of failure with the Bongo cooling system is very high, so I can only pass on the fact that it worked for me. This can't be taken as a recommendation that vac filling is right for you, or in any way 'better' than the tried & tested see-saw method as well documented. For me I'd struggle to find one willing assistant most of the time, never mind 2 so it was simply more convenient for me to be able to just get on with it on my own.

[Bogmonster40]

Dave-aber - I was going to say why didn't you give me a shout so I could pop round and watch you do it, thinking you was up the road from me in Aberdare = did not realise you was in blinking Elgin !!!! That would have been quite some run for me.....

[haydn callow]

Might be a good thing for somone to buy 3 of these kits and rent them out...