jlutherva

Any DIY's available for changing the coolant? Tips, hints?? Anything? If I just drain from the bottom of the radiator, does this empty the block? How do I empty the reservoir?

Jim

ZedO6

My suggestion is cycle out the old coolant with multiple flushes. Drain, fill with water, run the car with the heater on, drain and refill and repeat. Probably 30 mins of this should have the drain "product" clear water. Once you see that, add in your final "fill" be it straight water or distilled leaving enough room for one or two bottles of Water Wetter. I do change out my radiator water regularly when not running coolant.

rustyguns

i just drain it once and then add 2 bottles of water wetter and fill it up with water.
seems to work really well ! temps dropped 15 degrees! and when hot it drops fast when you short shift i change it once a year

jlutherva

Thanks Zed, That makes sense. The antifreeze in mine is brand new so I'll save the initial draining. How do suggest disposing of the following flushes? That's a pretty low concentration to recycle...

Jim

jlutherva

Thanks Rusty,
I'm probably going to have to go back to antifreeze after track season so this will be a complete do-over every year.
Dang, that Royal Purple Water Wetter is expensive- $16/bottle!

Jim

c4cruiser

Just finished this project on my '87 for the upcoming track season. I wound up doing a total of 5 flushes to get nearly all of the old coolant out. Drain radiator, refill with water, start engine and run to 180 degrees, drain and repeat.

Don't forget to drain and clean out the coolant overflow container. Refill it with plain distilled water after the final refilling of the system.

I used distilled water for the flush cycles as it was on sale at a local grocery store for $.89 per gallon. For the final fill with distilled water, I added a bottle of Red Line Water Wetter.

Our county has a hazardous materials disposal place at the landfill and they take oils, oil filters, and coolants at no charge. Many auto repair shops recycle old coolant so it might be worth calling a few to see if they will take coolant.

froggy47

You can buy "generic" water wetter for a lot less, although I am sure RP & RL will testify THEIR water wetter is better because of bla, bla.

ZedO6

Good question. The first drain of antifreeze I stored, it was almost new and will be reused. I live in California and have had conversations with the city's "hazmat" team. They suggested I take the diluted drain flushes and pour it down the sink drain. Yeah, I know it sounds terrible but they told me it will get cleaned up by water treatment before it hits the ocean. Any other non-captured method is a problem as it will either migrate into the water table or drain to the ocean. I had planned to take it to our city's hazmat collection site but after talking to the hazmat team I followed their advice.

jlutherva

The NAPA dude told me the capacity is 20 qts. for the C6Z - is that correct? That's 5 gal! Five flushes is 25 gallons! I'm w/ Zed, the first flush can go to recycling, balance can go down the drain (city sewer).

Thanks for the help guys!

Jim

waddisme

Are you doing this for safety reasons or to improve cooling?

travisnd

When you drain the radiator via the petcock the reservoir will drain as well. You will have some left in the heater circuit and the block. Fill the system with plain water, follow the OEM bleed procedure and then run the car for a bit with the heater on to cycle that through. Then drain it again. After that just fill it with distilled water (available cheap by the gallon at Wally World) and a couple bottles of water wetter and then follow the OEM bleed procedure.

As for disposing... to be honest I just mix it in the big drums I keep my other fluids in and take them to the local recycling center. Probably not supposed to do it that way.

jlutherva

What is the OEM bleed procedure? Is this in the owner's manual? I was looking at it yesterday at the repair shop and it dawned on me that they no longer have radiator caps, duh. I did notice that the new DeWitts has a petcock drain.
Thanks,
Jim

jlutherva

Safety. I've usually been OK with the water temps except of one time at Rd. Atl. when it was over 100*F. Short shifting on the back straight got it under control. Now I have the DeWitts radiator, I expect no issues at all.
See ya next weekend at VIR.
Jim

travisnd

It's in the OEM service manual. The basics are this:

1. Fill the system through the reservoir to the full line.

2. Start the car with the cap off and let it idle for 1 minute.

3. Put the cap on and run the car varying between idle and 3000 rpms for 30 second intervals. I.e. 30 seconds idle, 30 seconds 3000 rpms, 30 seconds idle, and so on. You do this until the coolant temp gets high enough for the t-stat to open. On a C5 the OEM t-stat is 192 degrees (or maybe 194?). If you have a lower temp one then you do it until you get over whatever temp. You can go feel the radiator hose coming off the water pump to see if the t-stat has opened or not.

4. Turn the car off and slowly remove the reservoir cap letting the pressure dissipate. It won't be hot enough to spew anywhere.

5. Leaving the cap off, go turn the car on and let it idle for one minute.

6. See step 3... repeat the cycle a few times (the manual says 3).

7. Add water as necessary. Once you're done and the car has cooled, verify the water is at the COLD FULL line on the reservior.

jlutherva

Thanks Travis. That should get it done. This OEM manual is not available on-line w/o a subscription, right?

Jim

jlutherva

Well, that certainly was a time consuming project! I can see why few HPDE people would do it. In a C6Z w/ my new DeWitt radiator, I was only getting about 1-1/2 gallons of fluid out per flush. After four flushes, I still had a trace of antifreeze in the water. The last flush was with distilled water then I refilled with more distilled water.
Thanks fore you help everybody!

Jim