Best Way to Flush Coolant?
07-16-2012, 01:39 AM
#1
Rennlist Member
Thread Starter
Best Way to Flush Coolant?
This is for an '86 32V 928S Auto.
What's the best way to perform a coolant flush? I'm planning on using Zerex G05 from now on. Before then she was filled with Prestone, the green stuff. I want to make sure I get all the previous coolant out before the switch unless some residual can be mixed and cause no ill will.
I've been reading guides and posts all night and I'm certain on the standard stuff for draining: jack up the car, locate the two (2) 13mm drain plugs for the block and the single plug for the radiator, open radiator cap then let her drain out.
However, I'm stuck on the best way to actually flush. Water hose and let the pressure flow the system then rinse with distilled then fill? Or water hose then run distilled until normal operating temperature with heater on for core flush, dump and fill with Zerex? Or water hose, use Prestone Flush, water hose, distilled then dump then fill with Zerex?
The 928 coolant guide I saw said something about flushing with the upper and lower radiator hoses disconnected to make sure the radiator is cleared out. Is this standard or just more of an extra precaution step?
I've been reading conflicting statements on burping the system too. Doesn't the engine burp itself and I top off once the air gets expelled out after several minutes at idle? Or do I have to manually do it?
What's the best way to perform a coolant flush? I'm planning on using Zerex G05 from now on. Before then she was filled with Prestone, the green stuff. I want to make sure I get all the previous coolant out before the switch unless some residual can be mixed and cause no ill will.
I've been reading guides and posts all night and I'm certain on the standard stuff for draining: jack up the car, locate the two (2) 13mm drain plugs for the block and the single plug for the radiator, open radiator cap then let her drain out.
However, I'm stuck on the best way to actually flush. Water hose and let the pressure flow the system then rinse with distilled then fill? Or water hose then run distilled until normal operating temperature with heater on for core flush, dump and fill with Zerex? Or water hose, use Prestone Flush, water hose, distilled then dump then fill with Zerex?
The 928 coolant guide I saw said something about flushing with the upper and lower radiator hoses disconnected to make sure the radiator is cleared out. Is this standard or just more of an extra precaution step?
I've been reading conflicting statements on burping the system too. Doesn't the engine burp itself and I top off once the air gets expelled out after several minutes at idle? Or do I have to manually do it?
07-16-2012, 01:59 AM
#2
Three Wheelin'
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The system is self burping if the thermostat is correctly installed. There is a small hole in the thermostat that should be mounted in the up position. If not the system will burp properly.
I would not think much about distilled water. The water you use in flushing is not going to be in the system long enough to leave any residue behind. That is unless you have some really crappy water.
I would think cycling three or four times with water and disconnecting critical places like the heater core and the radiator flushing with a hose and fresh water.
I would not think much about distilled water. The water you use in flushing is not going to be in the system long enough to leave any residue behind. That is unless you have some really crappy water.
I would think cycling three or four times with water and disconnecting critical places like the heater core and the radiator flushing with a hose and fresh water.
07-16-2012, 03:12 AM
#3
Rennlist Member
Thread Starter
Yea, I just replaced the thermostat today, new o-ring and seal too. It was a Behr 83. I didn't see a hole but there was a raised bump which I used to orient the thermostat, the bump was up.
