Bongo Fury

Hello and good morning, as the title says I'm getting a slight coolant loss from my header tank with no obvious clues as to where it's going and was hoping someone may be able to shed some light on this
I've topped it up once a few weeks ago but on checking this morning it seems to be down again
Any suggestions would be very much appreciated

best thing is to look and when engines up to temperature

there are a zillion places it could be

rubber pipe,clip,steel pipe,rad,water pump etc etc

Have you got silicone hoses on. We have to constantly tighten them up. Could be one of the many.

No silicone hoses but just noticed the hose coming from the header tank as got a rusty colour stain on it so I'm hoping I've found my problem and then all I have to do is fix it

The rusty coloured stain on the tank in/out pipes is quite common and caused by the tank "boiling up" at some time and ejecting rusty coloured coolant. Unless the staining is recent you have probably not found your leak.

As far as I'm aware its pretty recent

al & chris wrote:Have you got silicone hoses on. We have to constantly tighten them up. Could be one of the many.

if your constantly tightening them up be prepared for one or more to snap without warning. replace them often, or better still remove them and replace with haydns clips which allow for the constant exp and contraction. or replace your hoses and clips for the proper mazda originals.

dandemann8 wrote:Hello and good morning, as the title says I'm getting a slight coolant loss from my header tank with no obvious clues as to where it's going and was hoping someone may be able to shed some light on this
I've topped it up once a few weeks ago but on checking this morning it seems to be down again
Any suggestions would be very much appreciated

pressure test the system and get the cap tested, that should show you where.

Northern Bongolow wrote:

dandemann8 wrote:Hello and good morning, as the title says I'm getting a slight coolant loss from my header tank with no obvious clues as to where it's going and was hoping someone may be able to shed some light on this
I've topped it up once a few weeks ago but on checking this morning it seems to be down again
Any suggestions would be very much appreciated

pressure test the system and get the cap tested, that should show you where.

Cheers Ady, that will be this weekend's first job

put a flat cap on the expansion tank, and inflate with a pump to no more than 1 bar via the over flow pipe on the exp tank.

Northern Bongolow wrote:put a flat cap on the expansion tank, and inflate with a pump to no more than 1 bar via the over flow pipe on the exp tank.

Flat cap not quite sure what you mean, will a garage do this or is it something I can do with abit of know how

prob best for the garage to do a pressure test.

Northern Bongolow wrote:prob best for the garage to do a pressure test.

Got it booked in for Saturday morning, but what exactly do they do and how's it work

This diagram shows how the expansion tank cap works and what it does. There are basically 2 seals, the top one and the lower one.
What Ady is saying is that if you replace the cap with one that has the top seal only (no lower seal, spring and red valve), then the system is open to atmosphere via the little black tube (top left). By connecting a pump to this small black hose you can artificially pressurise the system.
Once you have reached a pressure of 1 bar, leave it fo a few minutes and note the pressure gauge. If the pressure drops, then you have a leak somewhere and it should be easy to spot.
As Ady has said, DON'T exceed 1 bar or you may damage hoses and cause additional leaks.
and DON'T forget to put the correct cap back when you have finished

widdowson2008 wrote:This diagram shows how the expansion tank cap works and what it does. There are basically 2 seals, the top one and the lower one.
What Ady is saying is that if you replace the cap with one that has the top seal only (no lower seal, spring and red valve), then the system is open to atmosphere via the little black tube (top left). By connecting a pump to this small black hose you can artificially pressurise the system.
Once you have reached a pressure of 1 bar, leave it fo a few minutes and note the pressure gauge. If the pressure drops, then you have a leak somewhere and it should be easy to spot.
As Ady has said, DON'T exceed 1 bar or you may damage hoses and cause additional leaks.
and DON'T forget to put the correct cap back when you have finished

And I'm guessing this is done cold