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Rb20det: How To Properly Do A Full Coolant System Flush?


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Hi there

I was hoping somebody could give proper step by step instructions on how to perform a full coolant system flush on a rb20det engine.

I've done lots of searches, and found bits and pieces of information all over the place. I've read rb's are not the easiest to flush, and also have a screw which releases any air bubbles.

So what needs to be done to perform a proper full flush, which hoses to start from... heater hoses, radiator hoses, thermostat?

What's the technique used for releasing and making sure there are no air bubbles left in the system?

Thank you :P

thanks for that. ive read through that thread before, but it's a little confusing.

some ppl are saying to use the heater hoses on the firewall, others say to remove thermostat and do it from there, whilst others say to let the car run while leaving the top radiator hose off and letting it drain that way...

nobody really mentions anything about air pockets/bubbles and how to properly remove them, as well as what to do in terms of the screw on the intake manifold...

i really think there should be a sticky for this, it's a typical skyline engine, and this question gets asked often enough... a proper diy description of completely draining and refilling coolant on an rb20det.

how long does it normally take to get rid of the air bubbles/pockets? i unscrewed the air bleed bolt and had the car idling for about 45 minutes while slowly topping up making sure the radiator was always full. after 45 minutes very small bubbles were still coming out...

another thing, just dumping the contents of the radiator is about 4 litres, so that leaves another 6 litres or more left in the rest of the system. how can i drain as much as possible out of the rest of the system?

i don't know why no one has mentioned this before but why not read the engine manual, its free to download.

http://justskylines.com/knowledgebase/asse..._engine_man.pdf

page 85 and onwards has the coolant info everyone wants.... and its from nissan.

i don't know why no one has mentioned this before but why not read the engine manual, its free to download.

http://justskylines.com/knowledgebase/asse..._engine_man.pdf

page 85 and onwards has the coolant info everyone wants.... and its from nissan.

this is for a r32 though. that engine manual is for r33

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