Draining Coolant

[IanD]

Hello all,
Am planning to drain my coolant at the weekend so that I can replace the upper radiator hose which has a small leak. Will then refill and bleed. The workshop manual says to drain the radiator and then the radiator hose upper pipe by removing the drain plug. Does anyone know where on the pipe the drain plug is? Have been out with a torch this evening and can't see it, maybe daylight will help

Found the leak thanks to one of Haydon's alarms. Allowed us to top up and get home. Hopefully it has saved us a load of money.

[Simon Jones]

There is no drain plug to the best of my knowledge. There is a very small screw valve on one of the metal pipes, but this is not going to make any great difference. Removing the bottom hose will get most of the coolant out, although you can get more out by disconnecting one of the hoses to the rear matrix, but this is not necessary to replace one hose. Worth using a hose pipe to flush out the system thoroughly. I knocked up an adapter to make this a bit easier:

[teenmal]

Hi IanD,

The drain plug is at the O/S bottom corner of the radiator.

Its 15-207 on the diagram,bottom left hand corner.


http://lushprojects.com/bongopartsmk2/c ... mgno=.html



Cheers.

[Northern Bongolow]

a little unusual for the top hose to spring a leak unless its swollen and soft.
if this is the case check the hose out of the head under the drivers seat too. if this is also swollen it may hint at thermostat problems.
make sure you are familiar with the bleed proccess you are using as this must be done correctly.
there are 3 videos on youtube titled how to bleed a mazda bongo, these show ONE way to bleed your bongo.
i dont wish to alarm you at all, but wish to make you aware of the pros and cons of the coolant system.

[widdowson2008]

There is no drain plug to the best of my knowledge.

There actually is a plug Simon, specifically for purpose of draining (see Mazda manual).
On the following diagram, it's just to the left/above of the 'W' - part number 13-104T

Short of removing the bottom end of either of the rubber hoses 15-183 or 16-186, there is no other way of getting coolant completely drained from top hose and pipe (engine to radiator top).

[Simon Jones]

I stand corrected . Never recall seeing that on either of my Bongos. Removing bottom hose certainly makes flushing easier.

[IanD]

Hello all,
Thanks for all the info, very helpful.

Like the idea of the hose adapter. Might make one of those myself. Thanks.

I've had another look and I think I've found the drain plug. I found the one on the radiator already but waned to make sure that I got coolant out of the steel pipe that hose 15-183 is attached to so that coolant didn't poor out all over the place.

It is hose 15-183 that is leaking. It is swollen at the bottom where it joins the steel pipe but this seems to be becuase someone has replaced the constant preasure clip with an old jubilee clip. Unfortunately they left the preasure clip on which has squeezed the pipe and cuased a bulge. The hose appears to be leaking from the top where it joins the radiator. It is quite perished there, so I think its the join rather than a split the in the pipe. Can't do any harm to replace it though.

I've watched the videos on you tube and have got a workshop manual too. I think I'll go for the Mazda method as it seems like less of a faff. Am planning to drain as much coolant as possible, replace the hose, refill and and bleed.

Hopefully all will be ok.

[IanD]

Thanks for the heads up on the hose under the drivers seat. Will take a look at that before I do anything, just in case iti is the stat.

[Northern Bongolow]

good luck with it mate.
where the rubber pipe has been double clipped, check the underside of the steel pipe its fixed to. the steel pipe for some reason tends to get a rust scab on its underside and can hole, thats usually the reason for the need to double clip as the last person there never spotted it .

[IanD]

Thanks very much for the tip, I'll check that when I get the hose off. I checked the hose going into the head under the drivers seat and it looks fine, seems fairly new. No bulges or anything so hopefully we haven't got any thermostat problems. I've noticed a bit of dried coolant around the end of the rubber hose where it joins the steel one, hopefully its just where its collected as it ran down the pipe. If the steel pipe does have a hole in it, do you have any ideas for fixing it?

I just hope the weather is good on Saturday so I can get on with it.

Thanks again.

[Northern Bongolow]

its usually near the end of the pipe, you can shorten the pipe a little or just move the clip up abit.

[IanD]

Tip top, thanks very much

[IanD]

Well, the weather held out and I managed to get the job done. Drained coolant and replaced the hose, the steel pipe was rusted at the end exactly as Ady said. I'm still not sure why the 2nd preasure clip was left on the hose, it wasn't over the steel pipe at all, it was just squeezing the hose. Refilled and bled the system using the Mazda method. Bongo behaved exactly as the manual said. Bottom hose got hot and heaters all blowing nice and warm. Coolant level is good and the temp guage is stitting nicely at 11 o'clock. Took Bongo for a decent test drive up some massive hills and all was well.

Thanks again to all for your advice, very helpful.

[stevearmitage]

Im looking at bleeding my coolant, I've seen the youtube bids, whats the Mazda method? Can you point me in the direction of a decent workshop manual as theres 2 on ebay that are quite different in price.

Cheers

Steve

[IanD]

Hi Steve,
I bought the workshop manual that's sold on the Bongo Fury shop. Its expensive, but it is really worth the money. The translation is very good and the diagrams are very clear. The Mazda method is also outlined in the Coolant factsheet in the members area of the website. The most expensive one on ebay is the one I have. The club shop sell it cheaper though.

Good luck