Hello BongoJoe,
A 3 way pipe fitting is another option to replace your existing 2 way one. The 3rd outlet goes to the new bleed pipe.
However another option is to fit a header tank from a 2l petrol (which I think is standard) if you can get one, they have another inlet at the top. Geoff- please correct me if this is wrong Sir.
If you run a pipe from the 3rd outlet to the top hose connection on the header tank the system will mostly self bleed the air out.
You still have to get the engine up to 82c to open the thermostat before the air and coolant will start moving fully.
Another more expensive option is to fit an auxiliary electronic water pump, (my Freda already had the 2l petrol header tank) this is the path I chose and I don't regret it. See my earlier post-
https://igmaynard.co.uk/bongo/forum/vie ... hp?t=78512
With the tiny toggle valve on the thermostat removed, coolant can flow regardless of whether the thermostat is open or closed, albeit slowly.
This makes bleeding the air out a very easy job (with the non standard header tank), you don't need a pipe and funnel. Another huge advantage with an EWP system is that you can decide the temperature your engine runs at and switch the fans on at a lower temperature than the ECU normally would.
There's an argument that diesels need to run hot in order to achieve their optimum fuel efficiency. I can only agree with this (as advised by a mechanic friend of mine) but the relative cost of a few lower miles per gallon verses a replacement cylinder head or gasket is small change in my opinion. I've had both go wrong on my Freda, first the head cracked- then replaced, and a few years later the gasket failed.
All of the coolant issues I have experienced can be attributed to bad design- sorry if this offends, but back in the day Mazda should have looked more closely at the impeller size and the volume of coolant in the system. When the engine is ticking over with no airflow they get very hot. The ECU starts the fans on a diesel at 96c at low speed, and full fans at 108c. Its no wonder things go very wrong so quickly. The smallest amount of sediment restricting coolant flow will magnify problems greatly.
After fitting a Davies Craig EWP system in my Freda, the coolant temperature has never exceed 98c, even when climbing an endless hill in France in 34c summer temperatures.
Trust me Gents, this is the way forward. Its expensive though.
Any questions are most welcome.
Clever people the Japanese.
