Parts availability

[Ron Miel]

He told me that there wasn't anything really complicated about changing the coolant, and the Mazda Bongo isn't unique in having a complex coolant system. Now I must point out that the mechanic is the least arrogant person I know - he's just laid back and knows his cars, including Jap imports.

My point is, if you know your mechanic, and they know their stuff, then trust them to do what they do best.

Andrew

So how did he refill the coolant, did he use a vacuum fill, bleed it using the bleed pipe? or did he just get lucky?
It isn't complicated, as anyone can see from the bleed video (other methods are available ) it's just a matter of ensuring no air is left in the system.

Good questions Kirsty. Having just given an unqualified "RECOMMENDED" to the ("Bongo-friendly" listed, and forum-recommended) garage I used for a service/coolant change/MOT last week, it's possible I'll have to modify my recommendation this week.

I supplied a carefully measured 13 litres of pre-mixed coolant, and was surprised to find a smallish amount left - haven't decanted and measured (yet!) but there could perhaps be getting on for a litre. However, I was assured that the system had been Bongo-bled properly but they don't always take the full 13 litres re-fill - I assumed, perhaps because they don't always easily fully drain in the first place (something I have experienced, with another motor in the distant past). Drove home, 90 miles cross-country, including some very steep Pennine ascents, and finding temperatures normal, with zero change in the expansion tank cold coolant level (still today, after another 100 miles or so, of use), accepted that he had done the job properly.

Yesterday, however, was the first fully dry day here, since getting the van back on Friday, so only then did I shift the conversion-reversed rear seat out of the way to have a look in the motor:

SHOCK! HORROR! The bleed pipe was detached and removed by me a couple of months back, after a rear heater matrix failure and by-pass, and I used a particularly wide cable tie to re-secure it. It was still clipped firmly in place yesterday - seemingly by the same cable tie!!!!!! Because of the way I had deliberately cut the tie right back, it was impossible to remove without cutting, and it could therefore not have been re-used.

So, looks like I was lucky on the drive home, and there may still be air in it - will now be re-bleeding it properly myself, before it goes on the road again, and I'll report here how much more coolant it then takes, if any.

[missfixit70]

I wouldn't hold the fact that they didn't get 13 litres in against them, it is virtually impossible to drain every drop of water out, hence it's so important to flush it REALLY thoroughly until the water runs completely clear, as you will get left with some in the system. Did this the other day & even blowing through the bleed pipe with rear heater stub disconnected & drained everwhere possible, I think it was only @ 10 litres we got back in (rear heater & pipework being removed only accounts for @600ml).
BUT, the fact that the bleed pipe wasn't disturbed could be a bit of an issue, although they could have used vacuum fill?

[Ron Miel]

I wouldn't hold the fact that they didn't get 13 litres in against them, it is virtually impossible to drain every drop of water out, hence it's so important to flush it REALLY thoroughly until the water runs completely clear, as you will get left with some in the system. Did this the other day & even blowing through the bleed pipe with rear heater stub disconnected & drained everwhere possible, I think it was only @ 10 litres we got back in (rear heater & pipework being removed only accounts for @600ml).
BUT, the fact that the bleed pipe wasn't disturbed could be a bit of an issue, although they could have used vacuum fill?

Thanks Kirsty. Was going to ask re the usual drain percentage, as I've not yet done a full coolant change myself. If this does turn out to have been an incomplete re-fill/bleed, I'll be doing the next one though! If not, I will ask them if vacuum fill was used (how's that done?), then confirm it here.

TBH, I think I would have been told if it had been though, as I did question them pretty carefully when I found a fair bit of coolant still remaining (now decanted/measured, and actually 3.2 litres - well, it was in the bottom of a 25 litre container!), although, by your reckoning that's perhaps about right. I did also specifically question the drain amount though, and was told that fullest possible draining had been achieved, by removing the block drain plug as well as the radiator one. We'll see - but I clearly must double check.

[Ron Miel]

I wouldn't hold the fact that they didn't get 13 litres in against them, it is virtually impossible to drain every drop of water out, hence it's so important to flush it REALLY thoroughly until the water runs completely clear, as you will get left with some in the system. Did this the other day & even blowing through the bleed pipe with rear heater stub disconnected & drained everwhere possible, I think it was only @ 10 litres we got back in (rear heater & pipework being removed only accounts for @600ml).
BUT, the fact that the bleed pipe wasn't disturbed could be a bit of an issue, although they could have used vacuum fill?

>
>
......If not, I will ask them if vacuum fill was used (how's that done?).....
>
>

Found the professional kit online for doing vacuum fills - no, I don't think so. Sure he would have told me. Anyway, I'll crack on and re-check bleed completeness later this week when I find time.

[Alacrity]

If you no longer have a rear heater matrix in the system that will reduce its capacity a bit & I can't see you would get everything out of the system anyway. I always use a vacuum fill system here (I have garage facilities) & never had an issue yet. However I do always check the bleed tube afterwards to be certain. Not normally anything much in it air wise. I did my last one in January - about 3000 miles ago & not had an issue yet. I have to say I have never measured the amount to go back in though.

[missfixit70]

If you just bypass the rear heater matrix I doubt you'd notice any difference in the system capacity, the capacity of the matrix itself is a mere 160ml http://www.igmaynard.co.uk/bongo/forum/ ... 0&start=45 by the time you've added in a hose to do the bypassing, it would probably just about replace that capacity