Another Coolant Alarm Issue

[John_H]

Why would that be a problem?

ummm .... well I would have thought that if it was pressurised it would have a pressure cap on it.
Looks like I need further information please

[Bob]

Surely all modern vehicles have a pressurised cooling system.

No problem at all removing the pressure cap while cold but it will blow boiling coolant at you if removed while hot.

If you have a Bongo without a pressure cap on the cooling system some pics will help us to help you.

[Simon Jones]

It does have a pressure cap which blows at 1.1 bar. If you get one of Haydn's alarms, there is no need to cut the tank as all it needs is a small hole drilling for a sensor screw to be fitted.

This is the 2.0 tank which has the extra pipe for the self-bleeding system:



The yellow cap on the left is for expansion tank while the red one is for the radiator. Despite what some people say, the two caps are different as the yellow one has a different pressure relief mechanism (as can be seen that it does not sit flat as the red one does):

[haydn callow]

As. Matter of interest where does that 'extra' pipe go to??

[Simon Jones]

I've never looked but imagine it goes back to the head somewhere.

[haydn callow]

So if you fitted a 2lt tank to a 2.5lt Bongo and connected the bleed pipe to it ....would that be the end of all the bleeding problems?? Just thinking!!

[haydn callow]

Going a step further....if I come up with a DIY tank spigot that can be retro fitted above the FULL line...would that work??

[g8dhe]

I thought it already had the spigot but the plastic has not been drilled out ?
I've often thought the same thing about making it self bleeding, but having a V6 and not doing my own mechanical maintenance its never been a massive worry!

[John_H]

Here's my 2 litre header tank and pressure cap - no third pipe on mine!! and, yes, it does have a pressure cap so does this system need bleeding like the diesels?

[g8dhe]

Eh ?

[John_H]

thanks Geoff: It looked a lot different to the pic Simon posted - I really must get an eyetest (sigh)
Haydn - The Landy alarm I made didn't have a float system, too much swaying about in them motors for that
I have a feeling it used a 555 and a transistor ... must find diagram.

[Bob]

No, the 2 ltr petrol does not need bleeding like a diesel.

The 2.5 V6 petrol does.

[Simon Jones]

So if you fitted a 2lt tank to a 2.5lt Bongo and connected the bleed pipe to it ....would that be the end of all the bleeding problems?? Just thinking!!

I tried extending the bleed tube up to the expansion tank and just poked it in the top. I was hoping there would be sufficient flow to force the coolant up to the tank, but there was not unfortunately. That was when I knocked up a bleeding tool using an on/off valve, windscreen washer reservoir tank and pipework to go up to the header tank.







To bleed it, open the valve so coolant flows into the washer bottle and run the pump to recirculate back into the tank. If you adjust the flow, the valve can be left open so it just flows round and round with the washer bottle allowing any air to be flushed out of the system.

Whether you could permanently extend the bleed pipe and run it up to the spare spigot on the header tank, I don't know. My gut feeling is that it would be more likely to allow air back into the head rather than allow coolant to flow out.

[John_H]

Haydn - The Landy alarm I made didn't have a float system, too much swaying about in them motors for that
I have a feeling it used a 555 and a transistor ... must find diagram.

After a lot of digging about here's the circuit I used for the coolant alarm - it has a single probe in the coolant tank. OK for use when stationary but what would it be like on the move in a Bongo - does the coolant slosh about and activate your alarm, Haydn?

[Bob]

I've got one of Haydn's and have never had that happen.