Coolant replacement query

[Greenmachine96]

Hi

Diesel engine here.


I've seen lots of information on bleeding the bongo after coolant change. But there's not a lot of info on getting old coolant out.

Do I simply disconnect lowered rad hose? Does this get access to whole system or do I need another hose of too?

Do I need clear access under the car as I was hoping to do flat on driveway? If not I've got some ramps and axle stands.

I'm doing a belt change and water pump at same time. If I need to move the bongo or run the engine in between stages, will I damage the engine for a few minutes if running without coolant?

I need to do the coolant change solo - any tips??

Thanks all

[gilly99]

Not for the feint-hearted!! Front and rear heater matrix's and meters of complex pipework. For a full coolant change, really need to back-flush the radiator and heater matrix's, ie by disconnecting inlet / outlets. If you are doing belts, you might want to order the pulleys or at least know where they have stock, as they have a habit of disintegrating.

Bleeding after a complete coolant change is a major task. You might be better buying a proper auto vacuum filler kit.

Personally, I would not run the engine without coolant at all.

[Doone]

You can drain by undoing that hose and the radiator stop cock. Remove both pressure caps to speed up draining.
But it leaves approx 1-2 litres still in the system.
So if you undo the thermostat housing, you get more out.
And you can change the thermostat at the same time, which is always good... unless it's been done recently. If you do change it, I recommend fitting a genuine thermostat.

Easier on a ramp.
I don't know why you'd need to run the engine between stages, but I wouldn't, if there was no coolant in it.
And of course, bleed it. Plenty of info on YouTube, showing different methods.

[Greenmachine96]

Not for the feint-hearted!! Front and rear heater matrix's and meters of complex pipework. For a full coolant change, really need to back-flush the radiator and heater matrix's, ie by disconnecting inlet / outlets. If you are doing belts, you might want to order the pulleys or at least know where they have stock, as they have a habit of disintegrating.

Bleeding after a complete coolant change is a major task. You might be better buying a proper auto vacuum filler kit.

Personally, I would not run the engine without coolant at all.

Wow. That's a concern - the pulleys might disintegrate!? Wouldn't they fall apart in situ when the car is running?

So I only have one aux belt. The suggestion previously was to replace both at once. That means then replacing all belts. Which then suggests may as well replace water pump at same time. Which then means replacing/ bleeding coolant.

My coolant is currently clear - so probably just water!

Again - any tips or should I just plough on.

Thanks so far.

Re moving car between stages - I live on a hill - my driveway is a bit of a slope, so was hoping to do all dry work on driveway, but then move car to somewhere more quiet where I can bleed and rev engine.

[Bob]

When you say the 'dry work' that can’t include the pump replacement as you will loose coolant.

If it looks like plain water in the system I would get it done ASAP as it’s getting cold.

The antifreeze also has a corrosion inhibitor, which is important and is why it must be replaced regularly.

Lastly, don’t even think about driving it before it’s bled after coolant loss.

[Greenmachine96]

Help please. Very frustrated bleeding bongo.

I couldn't change the water pump in the end. The pulley bolts were to tricky so I settled with changing the belts I needed to do.

I also changed the coolant, even though I had no issues with the engine or coolant, but worried about it being just water. So on to bleeding.

After a 90mins of 2500 for a few mins followed by idle repeat, got lots of bubbles out but they never quite settled. Periods of very calm followed by some small plugs/bubbles. Nothing violent all quite gentle. But at no point did the bottom hose get warm. Temp guage (original) in dash got up to 11oclock and stayed there throughout.

Thoughts? What can I do? Very frustrated so any help would be great.

[g8dhe]

If the bottom hose didn't get warm then thermostat didn't open up! Not sure what temperature your working in but down here it has been sub-zero all day so it might need a lot more time than 90 minutes to get sufficiently hot to open the thermostat. Assuming your thermostat has been working correctly previously of course.