Cooling system pressure test kit anyone? DO NOT DELETE

[missfixit70]

These instructions sent through to me (from someone who'd prefer to retain anonymity) might come in useful finding those pesky leaks & generally fault finding on the cooling system

The Bleeding Northerners Coolant System Test Kit

As most of are now fully aware of how to Bleed a Bongo successfully, the next mission should you choose to accept it is to help those diagnose possible faults in their systems. If you have leaks, you cannot bleed successfully. You can check for Bulging and Weeping Hoses. You can check the stat operation and the fans coming on and the Mason setting using the following method to ensure that all is well.
Make sure system is full of water
Remove expansion cap and expansion overflow pipe and fit the kit shown below


System Kit

This Kit consists of

1.A 2Bar Pressure Gauge
2.A Nissan Micra 0.8b Radiator Cap
3.A length of Rubber Pipe, to fit on Expansion Tank Overflow
4.A Wagon or Car Valve and Stem to inflate
5.Foot Pump or Bike Pump
6.Assorted Clips and Rubber Seals/Washers

How make:

Take the 2b Clock and a suitable Bulk Head Fitting and assemble, MUST be airtight
Get a Nissan Micra or similar Japanese Radiator Cap and drill out all the centre to a suitable size that can accept your bulk head fitting
Take care to save all the rubber washes from the old cap. You will need these later.
Assemble as per pictures below:


Pressure Gauge fitted to Radiator Cap


Side view of Radiator Cap with Pressure Gauge assembled


Underside of the Fitting

Once this is built, you may have to bend the securing lugs over slightly to make a good airtight seal. Take car, don't bend too much as you may damage the header tank.

Static pressure test or The Leakfinder General

Put onto header tank and inflate the system using the newly made pipe which is placed on the old overflow connection on the header tank. Inflate to 1bar pressure.
You now have time to check all hoses and connections for leaks etc. with the engine not running. Check periodically that the system is still up to pressure and rectify leaks as you go.
Satisfy yourself that the pressure is holding & in theory you have a leak free bongo.
I don't know whether it would show if you had a head/gasket leak doing it cold & static.


Dynamic pressure test

Not sure how much use this is as a diagnostic, but it may be useful, or just interesting in an anorak kinda way
When happy that the system is holding pressure and air tight;
1.Remove the pressure via the inflation valve and remove the gauge from the expansion tank.
2.Remove the inflation pipe, refit the breather pipe and standard header tank cap.
3. Remove the radiator cap, MAKE SURE THE HEADER TANK CAP IS ON BEFORE YOU REMOVE THE RADIATOR CAP OR YOU WILL DRAIN THE WATER FROM THE HEADER TANK AND GIVE YOURSELF AN AIR LOCK.Fit the gauge cap to the radiator cap, If you leave the gauge on the expansion tank, you will not have any pressure relief system in place!.
4.You may now start the engine.


As we all know pressure is generated alongside heat and should both raise together. There is some law about this, but don't know what it is.


As you raise the temperature you will notice the pressure rises. You can actually note the pressure and temperature as the Thermostat starts to open (bottom hose Warm) which is approximatley 0.25bar (2.5lb) and a Mason corrected temperature of about 11'o'clock.


Warming up pressure


Warming up temperature

As you increase revs to gain temperature, you will notice the pressure raise accordingly until you get to a point where you can get your Mason to Chirp (Ours set at 4.5, just before the radiator fan cut in point) I set my Mason at this level to indicate a slight raise in temperatures during road use and to expect my fans to cut in shortly after and dump the engine heat shortly after.




Mason Alarm Setting

Continue to increase temperatures until shortly after this point the Radiator Fans come in and dump the temperature and pressure


Fan cut in Temperature


Pressure as Temp is at Fan Cut in Point

As the system is rated at 1.1bar on the Radiator and Header Caps the readings shown above would indicate that the maximum temperatures in the system and the maximum pressures shown display that the system is operating under it's safe capacity and everything is working as it should.
The final pictures below show the results immediately after the engine fans activate and dump the temperature and pressure.


Temperature after Fans have cut in


Pressure reading after fans have cut in

Conclusion:

All the above or very similar to should be observed if your system is in good condition with genuine Mazda Parts fitted i.e. Thermostat, Temperature Sender, Fan Switch and Good quality coolant etc.

I see this system as a guide only and should be treated as such, but feel it could help diagnose possible Head problems and Thermostat issues as these are quite often difficult to diagnose. If you have, say, a a Head problem the temperatures and pressures can be viewed to see if they differ from above. At this point this system has not been applied to a faulty system so your on your own with that. What the system does do well is find leaks and give a rough guide to the temps and pressures you should expect on a healthy system. For a Tenner (approx) it could help somebody out there.

You could make the Kit so the gauge could be read on the dash board with the necessary pipe work and adapters. I must stress the dangers of introducing hot water/coolant into the cabin area and don't feel this is suitable unless adapted with a hydraulic type gauge/sender or something similar. We could see that this would give useful information on the move but hell aren't we paranoid enough? Haven't we got enough warning systems and gauges already. All of which are useful and worthy in there own right. We just happen to use an LCA paired with a MASON and have not tried any of the other options on the market.

[widdowson2008]

Like it
Could you explain the bit where the stat opens and how you recognise when this happens (on the gauge) and ..........That'll be enough for a start.

[missfixit70]

Stat opening is not recognised on the gauge as such, it's recognised by feeling the bottom hose, the gauge won't indicate stat opening, it's just measuring system pressure. You may notice a slight blip, or variation, but I don't think it would be definitive.

[widdowson2008]

Never mind - can't have everything - still a neat piece of kit. Simple and foolproof.

Gonna make one and try it.

[missfixit70]

I'll try & get a bit more feedback & let you know, but so far it's only been tested dynamically on one vehicle, so it's difficult to say how useful it'll be as dynamic testing tool, it was born out of a need to statically pressure test the system to check for leaks on a hard to bleed bongo & it proved very useful, so it's still in development really We just thought it'd be useful to share for those having problems bleeding a bongo, a tiny weep or two can make a big difference.

[widdowson2008]

Every little helps, as they say. What makes this tool attractive is the low cost. Who knows what other uses it could be put to.

[mikexgough]

nice work............... it has answered a question I was seeking the answer to....

[haydn callow]

Nice one Kirsty....
Another way to check for leaks is to remove the Valve from a high pressure cycle innertube (saw it off near the tube) and this will then "self tap" into the header tank overflow stub. Then just pump a bit of air in, (a pump with a gauge is a bonus) but the tank cap valve will blow if you give it to much.. (remove the valve when finished)

[falcoron]

I'll try & get a bit more feedback & let you know, but so far it's only been tested dynamically on one vehicle, so it's difficult to say how useful it'll be as dynamic testing tool, it was born out of a need to statically pressure test the system to check for leaks on a hard to bleed bongo & it proved very useful, so it's still in development really We just thought it'd be useful to share for those having problems bleeding a bongo, a tiny weep or two can make a big difference.

Well i can testify to that. had a hell of a job bleeding mine and with help from ( all who know ) i pressurised mine and lo and behold 2 leaks. Never lost coolant so not apparent to me so it must have been gathering in some air.
this is a great wee kit and im gonna make one. Today ( i have gauge here) but if you want a quick way Haydns Is good or do what i did;
get a cheap pump cut the end off the tube, push tightly into a silicone sealer tip and then push this up your expansion overflow pipe.


Gently pump air in and look for leaks.
Only issue i can see with this is you dont know how much pressure you have so may not get all leaks. With the gauge you can get it to where it would be on running so find every thing.
Have fun!

[missfixit70]

Plus with the gauge you can see if it's holding pressure, but it's good to see other people's suggestions along the same lines, keep them coming

[widdowson2008]

Plus with the gauge you can see if it's holding pressure, but it's good to see other people's suggestions along the same lines, keep them coming

.....and THAT'S the clever bit................Simple, but clever

[maxheadroom]

is this gauge any good for the job?@ only £5.99

http://cgi.ebay.co.uk/2-bar-0-30-psi-pr ... 35a7674982

[missfixit70]

Looks ok to me.

[jumper]

My brother is a mechanic and uses this system to bleed my van, takes a few attempts to get any stubborn air locks out but it does work quite easily.

Ian

[missfixit70]

My brother is a mechanic and uses this system to bleed my van, takes a few attempts to get any stubborn air locks out but it does work quite easily.

Ian

Are you thinking of the vacuum filling system? This isn't a bleeding system, it's a way to pressure test & check for leaks.