Another Question About Coolant Bleeding

[BongoMTBer]

I will be carrying out a flush tomorrow and have been reading up from the excellent fact sheet.

However, there is an emphasis on having both heaters on full. Tell me if I am wrong, but doesn't coolant continually flow through both heaters, with the cabin temperature being controlled by varying air flow over the matrix? If this is the case, doesn't running the heater on full whack just increase the time it takes to heat the coolant to the reqd' temp for the stat to open?

I know my old Merc used to vary the flow of coolant through the matrix in order to modulate the cabin temp, and in this case, having the heater on full would be essential.

Just a thought?

[mikexgough]

I will be carrying out a flush tomorrow and have been reading up from the excellent fact sheet.

However, there is an emphasis on having both heaters on full. Tell me if I am wrong, but doesn't coolant continually flow through both heaters, with the cabin temperature being controlled by varying air flow over the matrix? If this is the case, doesn't running the heater on full whack just increase the time it takes to heat the coolant to the reqd' temp for the stat to open?

I know my old Merc used to vary the flow of coolant through the matrix in order to modulate the cabin temp, and in this case, having the heater on full would be essential.

Just a thought?

Your right the coolant flows through both heaters...... I tend to have the sliders on hot and leave the fans off, just turning them on to have a feel for heat from the heaters during the warm up part of the process.......there are no heater valves in the Bongo system unlike many older vehicles like the Merc you describe..... hope that makes sense.....
Mind you if the temperatures the Met office are predicting are right it will take a while to warm up anyway....

[daveblueozzie]

Every time i have had a coolant change from Wheelquick they always put both heaters on full blast, i did the same myself the other weekend after i changed the stat and coolant , it lets me know if the coolant is getting warm and whether i have air trapped in the system, cold air = trapped air in the system. well that what i think , i could be wrong.

[BongoMTBer]

Cheers Mike, that clears that one up!

Blowers off it is then.

[BongoMTBer]

Every time i have had a coolant change from Wheelquick they always put both heaters on full blast, i did the same myself the other weekend after i changed the stat and coolant , it lets me know if the coolant is getting warm and whether i have air trapped in the system, cold air = trapped air in the system. well that what i think , i could be wrong.

Fair one Dave, in that case, I will switch them on ocasionally just to check.

[BongoMTBer]

Does anyone know if there is a schematic system flow diagram available?

[mikexgough]

Widdowson is working on one.......he is almost there...... Here it is needs a bit of reading through

[BongoMTBer]

In a word, that is COOL.

We pay a lot of money for graphics like that to teach the future engineers of the RAF, hydraulics and fuel systems. Good work Widdowson.

[francophile1947]

It makes no sense at all to have the fans on when bleeding the system - just put them on to test the heaters when engine warm

[haydn callow]

Just turn them on when the engine is warm for a few seconds to ensure they are blowing warm =(full of coolant) then off again as having them on blow will slow the warm up a little....(whether it would slow them up to make much difference is another matter)

[missfixit70]

Just been covered to some degree earlier today here - http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=38084

[The Great Pretender]

I will be carrying out a flush tomorrow and have been reading up from the excellent fact sheet.

However, there is an emphasis on having both heaters on full. Tell me if I am wrong, but doesn't coolant continually flow through both heaters, with the cabin temperature being controlled by varying air flow over the matrix? If this is the case, doesn't running the heater on full whack just increase the time it takes to heat the coolant to the reqd' temp for the stat to open?

I know my old Merc used to vary the flow of coolant through the matrix in order to modulate the cabin temp, and in this case, having the heater on full would be essential.

Just a thought?

You need to understand that the feed to the heaters is taken from the block, this flow is what opens the thermostat. If this part of the system has problems it can be impossible to bleed the system. Keeping them on is a simple form of data logging as in blowing hot or cold.

[BongoMTBer]

You need to understand that the feed to the heaters is taken from the block, this flow is what opens the thermostat.

Thanks, I do.

[missfixit70]

Or rather than leave the heaters on you could watch the temp gauge rise & feel the temp of the heater return pipes?

[mikexgough]

Just a quick add on..... After you have bled the system and all is well, you will find that the Expansion Tank coolant level will drop approx 1" overnight...... so in the words of the Mike's at Wheelquick, Masabee, Nifty Nev and the majority of the Techies here would say..........

Check the level the next morning...... although the highly regarded Japanese spanner Masabee recommends checking visually for 3 mornings......