changing radiator fluid, back to Porsche antifreeze.

Preventative maintenance. Plus I've kind of come to like pink, in this situation anyway. Someone, PO, put the green stuff in and after a while, Don't ask me why, I got envious of folks with pink in their reservoirs. It's funny but it looks right. I did the water pump thermostat combo and since the antifreeze was questionable it seemed reasonable to flush the system and get official fluid back on board not that anyone else will care but... Reviewed the three-step method, then drained and collected all 6 gallons of the fluid to convince myself that the system was fully purged. Then I filled with 6 gallons distilled water, ran the car briefly, and drained 6 gallons again. Lots of green left. I know that I probably got more than 95% of the barfy green fluid out but I couldn't bring myself to fill with pink yet because, well, pink and green, eew. When looking back at elementary school arts projects where it gets tried I'm pretty sure that doesn't work out well most of the time. I read where guys are draining their antifreeze every three or four years and replacing it but they were only opening the drain plug at the motor, and getting 2 gallons So there was a lot left in the system. They were thinking they were getting all they could . Doing the math, at that rate it would take decades for a complete change.

I decided to research it more. There's a discussion in the pelican DIY library. Folks, antifreeze is not forever. Also, it's not that hard to change. Interestingly one of the problems with neglected coolant can be electrolysis and The pelican link showed a picture of a BMW block with internal associated corrosion that will give you the *******. I continued to forge ahead and drained 6 gallons again looking for the fluid to become clear. I've seen pictures of the green stuff kind of brown and that's what I was getting. Not pretty. I did it 4 times before it cleared. Here's a photo of it after the second or third flush. You can see that it's starting to clear but there is still significant remnant of the green coolant.

I'm all set to do the water pump and low temp thermostat, along with a couple new pipes. I guess i'll be doing the same multi-flush as I too wouldn't want to mix old and new fluids. Though i'm not feelig super confident about the job, so keep pushing it off.

If u pull the hoses off at the hard pipe near transmision gravity will drain almost all of the coolant in the system. Not a complete flush but it should be sufficiant.

Quotes source post: 19051304

And if you have an air compressor (who doesn't?) you can use a nozzle to inject air into one of the forward pipes and collect coolant from the other pipe. You will be surprised how much still comes out of there.

Awesome work. Great perseverance! It always feels good getting done with a job like this, knowing that it's much better than when you started.

Interesting. I used Ashai's method with an air compressor, and measured 6 gallons out, but perhaps there were minor old remnants left? Well mine was just regular maintenance so I'm not too worried about it. The one addition I will add is that I put a 3" PVC elbow fitting over the lower coolant line while blowing the system out. Ashai refers to this as being messy, but with the PVC elbow, all coolant was directed straight down into my bucket. Very clean.

Quotes source post: 19051752

There are two 90 degrees hoses that are removed for flushing. Put one back, pointing the end straight down. No need for a PVC elbow.

Quotes source post: 19051960

If following Ahsai's instructions as posted, then when removing the large hose to the thermostat, there is no natural 90 degree fitting there. Unless you remove the thermostat housing, but then you have to deal with gaskets, etc., and that wouldn't really be a good idea. For those that are looking: (even has a picture of the large hose, with no 90 degree angle on the end) https://rennlist.com/forums/996-foru...pump-tips.html

Quotes source post: 19052718

Will, I don't remember a 90� downturn option and if there was one I wish I would have been smart enough to see it but it's a great idea. I like the idea of the PVC elbow too. Just kind of cleans up the spewing of coolant although it wasn't that bad anyway. I used a piece of cardboard under my bucket and didn't have to mop much up with a rag at the end. Anyone looking at this and doing a thermostat water pump combo has already done the hard part in my opinion. Seems like a good time to flush and change over.

Items 41 and 42, two 90 degree hoses, found under the transmission. Remove both, install one with the bend pointing down toward collection bucket. Flush with compressed air.

Bottom right corner showing two pipes. That is where the two 90 degree hoses go.

Quotes source post: 19055096

So it seems you're doing it differently than the guide that Ashai posted then. I was obviously only commenting on my use of Ashai's specific instructions. If I understand correctly, the lines you indicate are to the heater core, not the front radiators. But I might be wrong. You should post more detail on your full method, and how the front rads get cleared. Maybe it's better.

This is what I do when I want to flush everything. I remove the two right angle hoses, and the the two large hoses at the bottom of the gearbox. I let it drain out, then I put compressed air in the smaller hose in the direction of the front of the car, judiciously pump air in squirts into the line and collect the fine specimen coming out at the other smaller hose into a 5 Gal bucket. Dump that, and switch to the large hoses and repeat. Dump that, turn the air around into the direction of the engine, repeat. There is not going to be much after that.

Sounds like that's going to work too. Did you get a full 6 gallons out that way? That should be pretty complete. I figured if I was getting 6 gallons out I was pretty much good to go for that round. Pink, who would have thought? Anyway, it's the little things...ahh.

I got everything out. Put bacl 6 gallons and more after a couple drives. I use Pentosin red, which becomes pink when diluted with water.

How long do you leave the bail open on the bleeder at the reservoir? And what does that thing do anyway? Let air in?

Quotes source post: 19059143

I use Airlift filling system so there is no need to bleed the system by leaving that valve open.

Quotes source post: 19059143

Depends how much air you left in the system. I also used the Airlift, but left it open for a couple of drives/heat-cycles. I didn't see any fluid level change, so closed it. Basically if you drive with the bail open, and the tank fluid level doesn't change, then no air is bleeding out, and you can close the bail. If you did a good job, it shouldn't take very long.

Quotes source post: 19059143

From my experience with the bleeder bail, it helps vent trapped air much faster/easier. I always leave the bail up after working on the coolant system to expedite air removal. Even after an air lift refill. I've even left the bail up for prolonged periods with no ill effects. On my 02 996 I've left the bail open all summer. jmo

The black bleeder valve on the coolant reservoir is not open to the outside, it connects the top of the two front radiators to the top of the coolant reservoir under pressure. It has a spring in it that opens progressively to pressure, the more pressure the more it opens....Lifting the bail prevents it from closing..ie, it remains open all the time connecting the top of the radiators to the top of the coolant reservoir.. After opening the cooling system, ( and Not using the air lift tool to refill ) leaving the bail up can help to vent the air from the top of the radiators more quickly, or if the engine experiences a hot spot that causes a boiling of the coolant in the heads/block, it will be pushed to the radiators and can get trapped in the top of the radiators and prevent cooling, so the bail will be lifted under pressure to move the trapped air to the reservoir, where it can be topped up, and the radiators will be filled with coolant and do their job. Leaving the bail up all the time has no big ill effects on the cooling system, just a slightly longer warm up time ( modern engines are designed to warm up as fast as possible)..

Quotes source post: 19059643

I have had very little change in the coolant level after multiple drives so I will keep watching but I'm surprised how well it seems to have filled just running the motor with the cap off for a few minutes, driving to the end of the block, and refilling. I can see how the airlift would really help in a commercial setting where you may not be able to justify a test drive for each vehicle but for me this has been just fine.