Coolant level alarm

[dandywarhol]

That worked...thanks....all is now clear.

....except the tank colour........

[haydn callow]

If anyone would like one of these "float units" please contact me and I will send you the one I bought to experiment with.


The bits

[missfixit70]

What were the results of your experiment then Haydn?

[haydn callow]

Without going into too much detail..not very encouraging...I defo wouldn't recommend fitting to a pressurized tank. I don't belive this type of seal was intended to be subject to this amount of heat/pressure.
You have to drill a 23mm hole after removing the tank from the vehicle, bleeding would be required after refitting. The seal failed at about 18 PSI which is quite a bit over the cap blow off point but getting consistant results with the seal is difficult. If anyone wants to progress with this switch they are welcome to this one and at their own risk. When we first tried to fit "our" sensors into the header tank 18 months ago we did try a similar type of seal and discarded it as unreliable in a pressure vessel. We tested our screw sensors and the tank goes before the screws .(over 1000 screws fitted and no reported leaks)

[Grahame at work]

The seal failed at about 18 PSI which is quite a bit over the cap blow off point but getting consistant results with the seal is difficult.

Haydn,

Thanks for doing the tests - very interesting - but can you expand on the "...consistant..."
statement you made. Also when you say it failed what type of failure was it?

Regards Grahame.

[haydn callow]

Thanks for that ....Very fair comments.
Merry "hic" Christmas to you and yours.

QUOTE
Is it any wonder the test failed if a 23mm (20.7 with Dec discount) hole was made to fit a 16mm probe!!!!!

As per instructions !!! The probe is 16mm...the seal is 23mm.
It is sold as a commercial product...I bought one.

[haydn callow]

Graham...The difficulty getting consistant results is knowing how tight to do up the "nut" which compresses the seal. Don't do it enough and it drips at quite a low pressure, do it to tight and the seal becomes deformed and it pours out. Getting it just right is (as you must know) a matter of feel. Get 20 different peeps and you would probably get 20 different results. In a non pressure tank there is lots of room for these differances but under pressure I don't belive there is. The best result I got was 18 PSI before a steady drip resulted. Another hassel is that you have to refit everything to test the seal.
This is why I say I don't belive this particular system is ment to be used in a Heat/Pressure vessel. Just my observations. I would not ... on what I observed recommend fitting them into a Bongo header tank.

The suggestion by the other post above that ""I would say that wouldn't I" is another attack on my integrity.
Those that know me, know different, and that's all that matters to me. I just say what I think and belive. If I get it wrong now and again..fair enough...few of us are perfect.

[mikexgough]

mmmmm.......... this debate looks like it's going to run for sometime, I used to make level sensors (on for much larger scale and applications and they used switch and capacitance electronics dependent on final application and type.
I do like the idea of the float method, but having worked with various plastics including PTFE and Polypropylene the seal gives me a certain amount of bother, irrespective of pressurised or not etc, my concern is getting the absolute seal on the tank and the longevity of the seal in service, Just another slant on the subject

I hope it works for those who are using or going to use the idea, I am sure there are Mason & Haydn users who will argue that theirs is the "best" system some say don't bother, others recommend new hoses, coolant and a bottle of Kseal for security or a combination of all of them ..........I personally don't think there is a "right way".........just your choice....... you pays your money and all that...........

For the record I do have an alarm fitted but it was the one that I thought was best for me and if you want to know which I have then see you at a meet somewhere as I am not going to reveal in here

[mikeonb4c]

Having changed (as many of us have) the ballcock unit on a few toilets and had to tighten the nylon nut, with the rubber gasket in place, so that you neither stripped a thread nor left a leak, I found this memory returned as I read this thread. I'm not saying this installation is the same, but given that heat and pressure are added to the equation here, I don't feel relaxed. If you drill that big hole and then find you can't get things to seal (and stay sealed - what happens over time?) then the way back is tricky. Unless I had a spare header tank I'd be disinclined to do it.

I didn't realy like even putting two self tapping screws (Haydns alarm) into my perfectly good header tank but just had to trust to the trials the supplier had undertaken (I accepted that trying to achieve Mazda's testing and compliance regime wasn't really a realistic possibility without their R&D budget so I had to make a judgement about how diligent the supplier had tried to be, and share the risk with them). 18 months later I'm pleased with my judgement. I've had no leakage at all and the alarm has reminded me twice that I need to top up on coolant.

[lindeelu]

I would like to reply to the original question:

Has any one out there fitted a new header tank from a different car with a level swilch in? peugeots have a float switch fitted to there header tanks it would be simple to wire a warning light or buzzer to the switch
any thoughts would be a cheap option

I know of a couple of landrover owner who have fitted volvo header tanks to their vehicles.

They suffered the same fate as the original tanks and split.

Tank splitting is quite a problem on some vehicles, but not the Bongo fortunately.

It is one of the most robust tanks around and incredibly strong thanks to it's internal baffling.

So, it might not be a positive move to fit a tank of unknown strength and longevity.

[mikexgough]

Thank goodness for the voice of reason.!! what a nice change

Well I suppose you have a balanced viewpoint when your day job commands that type of approach........

[Aethelric]

The float switch looks very good, but I must admit I can't see any advantages over the Haydn system. I'm sure the sensor is very reliable, but I can see potential failure mechanisms. Like the float hinge jamming or the relay welding closed (surprisingly easy to get very high instantaneous currents caused by the capacitance of long cables) or corrosion build up on the contacts due to low "wetting" currents.
These simply don't happen in the Haydn system. Given two choices I'd tend to go for the simpler one.
Dave

[haydn callow]

The float switch looks very good, but I must admit I can't see any advantages over the Haydn system. I'm sure the sensor is very reliable, but I can see potential failure mechanisms. Like the float hinge jamming or the relay welding closed (surprisingly easy to get very high instantaneous currents caused by the capacitance of long cables) or corrosion build up on the contacts due to low "wetting" currents.
These simply don't happen in the Haydn system. Given two choices I'd tend to go for the simpler one.
Dave

The advantage of the float sensor is just the cost...about £20 by the time you have fitted it...There are no contacts to get "wet" It is a simple float which has a articulated arm. Magnets embeded in the plastic cause the "switch" to operate.
Given the amount of "gunge" that can build up in the Bongo Tanks...this could be a concern...gumming up the hinge. However..I stand by my main argument..I don't think the seal between the 16mm float arm and the 23mm hole in the tank is reliable enough within the heat/pressure of the Bongo tank. The other big disadvantage is having to remove the tank entirely and then fit...test...bleed.

[Aethelric]

The float switch looks very good, but I must admit I can't see any advantages over the Haydn system. I'm sure the sensor is very reliable, but I can see potential failure mechanisms. Like the float hinge jamming or the relay welding closed (surprisingly easy to get very high instantaneous currents caused by the capacitance of long cables) or corrosion build up on the contacts due to low "wetting" currents.
These simply don't happen in the Haydn system. Given two choices I'd tend to go for the simpler one.
Dave

The advantage of the float sensor is just the cost...about £20 by the time you have fitted it...There are no contacts to get "wet" It is a simple float which has a articulated arm. Magnets embeded in the plastic cause the "switch" to operate.
Given the amount of "gunge" that can build up in the Bongo Tanks...this could be a concern...gumming up the hinge. However..I stand by my main argument..I don't think the seal between the 16mm float arm and the 23mm hole in the tank is reliable enough within the heat/pressure of the Bongo tank. The other big disadvantage is having to remove the tank entirely and then fit...test...bleed.

Hi Haydn, "wetting current" is a term used for the minimum switching current needed to keep the contacts clean (nothing to do with water). If reed relays switch very low currents, then they become unreliable. Mercury wetted relays avoid this, but I don't know whats fitted in the switch.
But, speaking from many years of experience, the main failure mode of a reed relay is to weld closed caused by the capacitance of long cables connected to the switches.

However, given all that, I would agree the dominant failure mode would probably be the seal.

Dave

[Trouble at t'Mill]

Haydn, can your system be fitted without removing the expansion tank? I'm curious as to how you prevent plastic swarf from falling into the tank when drilling? Or is it a tank-out job, in which case can this be done without introducing air into the system?

How long would you expect a (reasonably competent!) DIY install to take?

Cheers.