Coolant change help
 

Howdy folks,

This weekend I attempted to tackle the front engine mount replacement along with a new water pump, thermostat and coolant. After just completing the IMS, RMS and new flywheel/clutch and variocam tensioner pads project I thought I might as well take care of these other items while the car is on stands. I was pretty certain the engine mount was original and needed replacement as well. I was correct regarding the mount, it was cracked all the way around and was due for replacement.

My question concerns the coolant. I searched and read up as much as I could find regarding draining the existing coolant and which proper coolant to put in the system, etc. so I thought I was pretty well informed and ready. I ran the climate control up to high, removed the coolant drain plug as well as all three large hoses and the two heater core hoses that lead to the front radiators. I also removed the water pump and thermostat housing. I angled the car by lowering the back end and when complete I was still only able to get approx. 5 gallons of the old coolant out. Oh, I did remove the coolant cap as well. Coolant was green, could be original Porsche coolant from 2001 but I have no way of knowing for sure.

I did install the new water pump, thermostat, engine mount and reconnected all the hoses. I also have an Airlift to refill the system with the new Porsche pink coolant. I should probably fill the system with distilled water first to flush.

My concern is I think I did what I should have to remove the coolant but I didn't get the 6 or so gallons out. Will flushing with water once be enough to go ahead and refill with the new coolant? It may seem like a simple question but I don't want to make a mistake after getting this far and I want to put the car back on the road.

Thanks

Dave in TX
2001S

What was the minimum vacuum reading you maintained with the AIrlift throughout the entire refill process?
That may be the problem.

Short of standing the car on end and shaking it a couple of times, you are not going to get all the coolant out. The best you are going to get doing a gravity drain is around 80-85% of the system's capacity. Refilling the car with distilled water, then running it for a bit before draining will help get rid of any remaining old coolant.

I haven't used the airlift yet, so the system is still empty. I actually just kind of ran out of time this weekend so I thought I would stop here and get back to filling the system after some more checking with the experts.

Thanks JFP. I'll do that and cross my fingers that I haven't screwed anything up with all the work I have done recently!

Just be careful not to loose the vacuum when operating the valve/connecting the suction tube to the coolant. And of course do not pull more than the recommended max vacuum
I found it helpful to have the coolant in translucent containers to avoid sucking air. I found used 1 gal. milk jugs worked well with my Airlift clone.

I did exactly the same steps you did except I did 2 distilled water flushes because I to had Green coolant. I never got more than 4 - 5 gals out each time.
Once you get the vacuum up before refill, let it stand for a couple minutes. If it holds the recommended vacuum level, that should indicate you have no leaks.
I was prepared for up to 6 gals replace with 3 gals pink coolant and 3 gals of distilled water.
Now I have about 2 gals of 50/50 left over

You can also use one of the airlift "plugs and put in in the coolant line to the front and blow some compressed air through,. It should push out a bit more coolant. As JFP said, you won't get it all out

That's a good point. I am thinking 20 psi Max for the Airlift. Perhaps slightly less would be sufficient to load the system with coolant.

I have enough to make 6 gallons of pretty pink coolant. If all remains the same after flushing with water I will have some left over.

I thought that it would be sensible to somehow blow the coolant out instead of relying on the gravity approach but I couldn't really find much on that.

The "puge old coolant with pressure" could be an interesting next post :-)
We'll all be interested because you are right - replacing some of the coolant is only half the job done.
[QUOTE=dsallean;527060

I thought that it would be sensible to somehow blow the coolant out instead of relying on the gravity approach but I couldn't really find much on that.[/QUOTE]

I would be very cautious about using air pressure to push the coolant out. These cooling systems are designed to operate at around 18 PSIG pressure; going higher than that, which is very easy to do with an air line, can damage some expensive and hard to get at parts.

Absolutely agree with JFP in PA. Also these cooling systems get older. Don't force things.

I think the best method to get everything out is gravity. Where have you opened the system? Front or back. If back, raise the front of the car with a lift. Similar to the recommended filling process if you have no pressure system. ;)

Regards, Markus