Coolant change

[mikexgough]

Or, if you want to follow the exact instructions in the Bongo workshop manual:


Worked fine for me. A bit hectic keeping header tank topped up then returning to attend to bleed hose (more relaxing if a 2nd pair of hands could top the header tank up for you while you attend ot bleed hose. NB. Trying to put the bung in the bleed hose needs care also if you don't want scalded fingers!

I did my method single handed..... and without upsetting the neighbours with a high revving engine

[Allans]

A few of you have commented on the bleed method that Haydn has mentioned on this thread.

I understand this is also a recent addition to the coolant factsheet.

What has been written is similar to a method I used, after I fitted a water pump on his Bongo a few years ago. I bled it single-handed, it didn't take too long.

I ALSO use the Mazda recommended method.

And I have a few extras for those rare Bongos that are tricky to bleed by any method.

When Haydn watched me bleed his bongo, I had no idea that a version of it would end up on this forum as advice for others.

Haydn says he has used his method sucessfully many times to bleed Bongos.

If anyone is not happy with his method they can of course use Mazdas own method.

[eoptio]

thanks all for quick replies and advice, with a bit of luck will try it this weekend. Ref draining the coolant,just draining the radiator sufficient?

Another query ref oil: I have seen various recommendations on the forum what engine oil to use, 10W40 ok or 10W30 better or does it not really matter?

Thanks all

K

[missfixit70]

A quick read of this one should answer the first part - http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=35080

As for the oil, I use 5w30, plenty of discussions of the pros & cons on the forum, in all honesty, there's probably not a lot of difference, as long as the changes are regular.

[D n D & K]

how did you get on .

when i do mine i use a length of reinforced clear hose pipe attached to the bleed pipe . whilst the engine it at 2000 revs i can then stand at the front of the vehicle and use a syphoning method to let the water run into a bucket when the header tank get just above low raise the pipe to stop the flow then top up the tank from the bucket just keep doing this until the thermostat opens . its amazing how many bubble you can see travelling along the hose .

i have used this method twice now as i could not get on with the funnel method on my own .

[dom_e]

I'm gonna have to face a coolant change at some point soon and am likely have the thermostat replaced at the same time. DnD&K's latest method seems simple, but I'm still a little unsure of how this works if I'm honest.

I presume you just have to run around to raise the level of the bleed pipe once the header tank is getting low, then poor the water back in the tank and reapeat...

I think I may just ask a garage to do it!

[haydn callow]

Changed my Stat and coolant yesterday.
Apart from connecting the bleed pipe into the funnel at the beginning and removing it at the end of the process to replace the bung...I did the whole job without getting out of the drivers seat.
How come ??
I use a nice big funnel.
I have a Hi/Low coolant alarm fitted,
I have a temp gauge mod fitted.

By watching the level in the funnel and the Hi/Low alarm LED, I found I could maintain the level in the Expansion tank between the Low and Top of the tank by adjusting the engine revs...the funnel was a big enough reserve to replace any coolant demanded to replace air.
I could see when the Stat opened by watching the modified temp gauge ( cost of mod "less than 5p")

all in all a painless operation which took 35 mins

[dom_e]

I've had another look at the fact sheet and don't quite get how the coolant is actually changed in the last funnel technique. Where does the old coolant go when you add the new coolant to the funnel? Does it just overflow the header tank? Sorry if I'm being a bit daft!

Dom

[haydn callow]

You drain all the old coolant out before you start...then you fill up as much as you can with premixed new coolant ...then you start the bleeding.

Bongo BLEEDING Instructions (use yourself or INSIST your garage follows them)




NOTE.. (Before you start) Get a large funnel and cut the spout so the bleed tube will push up into it nice and tight.. Don't take the bung out of the pipe yet.

1..remove the plastic air scoop from under the bonnet.
2..remove the pressure cap off the expansion tank.
3..remove the pressure cap from the rad and fill to brim if it is not already full.
4..replace rad cap.
5..fill the expansion tank to the FULL line.
6..release the rad cap till coolant overflows and tighten rad cap.
7..top up expansion tank to FULL
8..under the passenger seat ..find the coolant bleed tube...remove the bung and push up into funnel.
9..half fill the funnel with premixed coolant.

Note..by raising/lowering the funnel and adjusting the engine revs you will from now on be able to control the level of the coolant in the header tank & funnel.
At no point from now on allow the funnel to empty or the header tank to drop below FILL.

10..start the engine...switch on heaters.....rev to 2500 for 3 mins....idle for 1 min.
11..keep repeating this cycle until the heaters blow hot and switch the heaters off.
12..carry on with the rev 2500/idle cycle..raising and lowering the funnel...you will have to do this for about 30/40 mins.....UNTILL THE BOTTOM HOSE GETS GOOD AND WARM..(stat open).

Once this happens carry on till all bubbles stop and replace the bleed tube bung (wear gloves..very hot)put the bung in as coolant is flowing out so no air can sneak in.

Top up the tank...replace the tank cap.....go for a drive and keep a eye on coolant levels for a few days....should be o.k. If job was done properly.

THE SECRET IS TO GET THE BOTTOM HOSE HOT WHILST BLEEDING (STAT OPEN)

[missfixit70]

I've had another look at the fact sheet and don't quite get how the coolant is actually changed in the last funnel technique. Where does the old coolant go when you add the new coolant to the funnel? Does it just overflow the header tank? Sorry if I'm being a bit daft!

Dom

It should be drained & thoroughly flushed before bleeding, especially if you're not sure if the new coolant is compatible with the old. Take off any hoses you can get to & flush through with a hose to get all the old stuff out.

[eoptio]

Hi

I have not yet had a go a this, building up courage.... doing some other jobs first, last weekend changed oil and all filters, this weekend planning diff oil, ATF fluid and brake pads. Then will have a go at the coolant change...

K

[mikeonb4c]

Or, if you want to follow the exact instructions in the Bongo workshop manual:


Worked fine for me. A bit hectic keeping header tank topped up then returning to attend to bleed hose (more relaxing if a 2nd pair of hands could top the header tank up for you while you attend ot bleed hose. NB. Trying to put the bung in the bleed hose needs care also if you don't want scalded fingers!

I did my method single handed..... and without upsetting the neighbours with a high revving engine

What's your method Mike? Can't find it on this thread

Haydn - I like the idea of being able to do the job single handed from the drivers seat. Could a person use your method without leaving the drivers seat if they only had a low coolant alarm? What size funnel (actual measurements) do you use and how do you manage to get the bleed hose to push inside the cut-off spout when it needs to be a tight enough fit to ensure no leak between hose and spout - it sounds like some very precise spout cutting is needed?

[haydn callow]

It's easy enough to cut the funnel so the tube pushes in and seals...just keep cutting a cm off till you can force it in. I will check the size of the funnel tomorrow.....I would be happy to do it without the Hi alarm.......If the funnel gets low then you know the tank is full and viza a viz

[mikeonb4c]

It's easy enough to cut the funnel so the tube pushes in and seals...just keep cutting a cm off till you can force it in. I will check the size of the funnel tomorrow.....I would be happy to do it without the Hi alarm.......If the funnel gets low then you know the tank is full and viza a viz

Thanks Haydn - I'm tempted to give it a go