4MIDLIF

The other day pilotshark posted a question about DexCool, and the subject of flushing came up.

What isthe best procedure for flushing the cooant system????

Chhers

pilotshark

What I have been doing is to drain all the old stuff out, including removing the dwo drain bolts under the engine. Refill with flush stuff and distilled water and run with heater on. Drain, refill with water, run with heater on and drain. maybee run one more system full of just water again depending on what the drainage looks like and then it is time to mix and fill with coolant. I am very open to suggestions however, if anyone has a better method.

Jimbo

Here is a link on flushing the cooling system.

<a href="http://www.nichols.nu/tip154.htm" target="_blank">http://www.nichols.nu/tip154.htm</a>

pilotshark

Thanks Jim. I read that. That is pretty much what I had in mind so I feel a bit more confident/reassured now.

Joe F

I know this will sound like heresy, but here goes. Has anyone gone to one of those quick lube places and had them flush your cooling system? I was in one the other day getting the oil changed on my Tahoe and the offered this back-flush for the cooling system where they basically power flush the system without removing any plugs from the block. I just wondered if anyone had tried it? If so, with what results?

TIA

<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

JF

Ted928

The previously mentioned thread (Nichols) says drain, add fresh water and run the engine until the water gets hot, drain, repeat.
I always thought that it was not good to run the engine with just water; I thought the lack of antifreeze as a lubricant would hurt the water pump seal. Any thoughts?

Thom1

Hi Sharks,

The service manual specifies a coolant change and bleeding procedure on page 19-1. In short: Set heater lever at warm, and run engine briefly. Remove expansion tank cap. Drain radiator and engine block. Fill coolant to top of reservoir. Run engine to operating temperature, and add coolant, if necessary, to let it settle at ½ of reservoir level. That’s all folks!

When I ordered some stuff from Dave Roberts. He said that there is a way to bleed air out of the radiator:

Radiator Bleeding:
Run car until warm.
Loosen clamp on the tiny hose at top of radiator – driver’s side.
Let air escape until coolant flows.
Tighten clamp.
That’s all Folks.

WARNING: A warm closed radiator system is under pressure. You can really get burned by opening a hot radiator.
I would also have the heater on warm before I tried to bleed any air.

Coolant Burping:
I would start with the expansion tank half full, cap off, engine cold, heater set to warm.
Burp the lower radiator hose by squeezing it several times.
Start engine.
Burp hose several times during warm-up.
If necessary, add coolant.
Replace expansion tank cap.

If you still suspect that there is air in the system go to the radiator bleeding procedure above. I should think that these 2 procedures should assure that air bubbles are removed from the system. You can even do the procedures a couple of times to assure yourself of removing air.

My service manuals did not mention these procedures. I kinda’ wonder if air in the system is really a serious concern.

Anyhow, HTH anyone with the air bubble concerns.
<img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

Ed Ruiz

Burping the system may be required, and if so it is a serious problem if not done. BTDT. I've helped others do it properly after their temp gauges started to climb into the Red zone. Follow DR's advice. YMMV.

BTW, it's ok to run with straight water for the flushing process. You won't be running the engine that long anyway. Besides racers usually run with only water. That green or orange stuff is terribly slippery when dumped on the track.