Coolant Flush For R33

[StevenCJR31]

^^ save yourself a backache and leave that plug in place. . You should be able to flush the cooling system well enough with just taking the hoses off etc

[D.I.Y. Mik]

Guys, guys, your doing it all wrong.... well sort of..... some of you.

Heres how i do it on my 32 with rb20det:

Empty old coolant and refill with cooling system cleaner, follow instructions on the bottle (warm up engine etc). usually you mix with tap water.

To flush, i pull the radiator hoses off the radiator end, blast radiator with hose from top & bottom.

Take out the thermostat for good flow and flush the engine with the hose from top and bottom.

Flush it heaps.

Put the thermostat and hoses back on. Fill it with coolant water mix.

To bleed, i jack up the front of the car so air goes to the front of the plenum, and i have a large diameter silicon hose that fits snug into the radiator neck.

And a hose with a small valve attached to the bleed nipple behind the head, on the heater hose. cos its a total pain to get to otherwise, youll see.

Then i simply open the bleed on the valve and the plenum, fill the big hose with coolant and watch it flow out the bleeds.

The level in the big hose is higher than the engine so it pushes the air out.

I run the engine between bleeds as i think it can suck air in if you bleed with the engine running.

You will find that after cleaning the system, it will go sludgy again.

This is just some leftovers, dont worry its probly quite clean now, so after a few days or a week, change the coolant again and it will stay clean.

Having the valve at the back, and the big hose for the radiator, makes it really easy to bleed it often and well.

[suwidji]

1. undo drain plug from bottom of radiator to flush old coolant
2. take hoses off, and take out old radiator
3. flush engine with garden hose
4. install new radiator + hoses
5. fill (radiator?) with new coolant
6. run heater and open bleed valve on top of throttle body
7. keep topping up coolant through overflow bottle when low
8. air hissing out of top bleed valve
9. when up to temp, coolant and bubbles come out of valve, close valve when bubbles stop

That's what i've taken out of this thread. Is this the correct method in flushing out the coolant system and installing a new radiator?

[StevenCJR31]

Sounds right ^^

[suwidji]

Hey all, so i got to changing the radiator and doing the coolant flush.

I'm up to bleeding the system, but I've been trying to get the car up to temp for the past hour! The thermostat isn't staying open. I see the fan turning on every now and then for about 2seconds, then it stops.

I haven't had to top-up the radiator or anything, and none of the bleed valves up top of the block are hissing out air or coolant or anything (i got them both open).

Any way i can speed this up?? I've been revving it at about 3000RPM in 30secon intervals, but no go.

[scotty nm35]

Sounds like your temp gauge isn't working perhaps. Is the radiator hose hot top and bottom?

Sometimes you can have an airlock which will stop water flowing, and keep the thermostat closed.

[FBRacing]

Before you drain your old coolant, be sure to throw in coolant flush which can be bought at any auto parts store. Follow the directions on the back. It'll kill any calcium build up. And if you really want to get crazy clean, take your radiator out and take it to radiator shop to have it "cooked ". That will clean every little bit of dirt and calc out of it. But since you have a new one going in, don't worry about cooking it. Once all clean and new coolant in, you could also use Royal Purples "Purple Ice" or Redlines "Water Wetter" which drops temps down a little more easier. Just my opinion though.