Coolant flow direction in hoses

[2000GotBoxS]

Hey Dennis,

The above picture is the CORRECT flow of the coolant. The cool water FROM the radiators comes back to the engine AT THE THERMOSTAT. I took the above diagram which Loren provided here, and I later discovered in the front of my Boxster Manual, and I color coded it, and I also added in more detail. I can send that to you, as I do not know how to post pictures on here. Send me an email to BrianMasek@hotmail.com and I will forward you the above diagram that has hoses and metal pipes called out and the directions of flow.

I managed to get all of the pieces out by back flushing each and every component separately. In other words, I disconnected the hoses, and then back flushed them all into 5 gallon buckets until all the pieces came out. A lot of the pieces actually came out of the heater core because that is always flowing water, along with the engine.

[Dennis Nicholls]

Thanks. I've got the green, orange, red, and purple arrow hoses on order - might as well change them all since most of the labor is refilling and "burping" the cooling system.

I got those four hoses installed yesterday. I'm still sore....ever since turning 60 it's been more effort to crawl under a car to work on it. The hoses I removed didn't appear to be in all that bad a shape on the insides. But I figure all will need replacing someday.

The AirLift worked as advertised. My small air compressor (14 gal. tank) had to take two passes to get to 25 in. Hg but it got there quickly enough. After 4 minutes with no change on the dial I let it suck in the coolant. Pretty slick operation.

[Dennis Nicholls]

Hmmm.....it turns out that the AirLift can give you false confidence.

I took the car out for a 40+ mile shakedown. When I returned it was leaking coolant and down about 2.5 cups in the reservoir. Turns out that I had neglected to tighten down the screw clamp on the "green arrow" hose. Fortunately the plastic undertrays make it obvious which connection is leaking. Unfortunately it took 2 hours to get the car up on jackstands, pull and clean the undertrays, then tighten the screw clamp.

The AirLift held a vacuum for 4+ minutes. I'm guessing that hoses make a better seal under vacuum than they do on over-pressure.

[JFP in PA]

Hmmm.....it turns out that the AirLift can give you false confidence.

I took the car out for a 40+ mile shakedown. When I returned it was leaking coolant and down about 2.5 cups in the reservoir. Turns out that I had neglected to tighten down the screw clamp on the "green arrow" hose. Fortunately the plastic undertrays make it obvious which connection is leaking. Unfortunately it took 2 hours to get the car up on jackstands, pull and clean the undertrays, then tighten the screw clamp.

The AirLift held a vacuum for 4+ minutes. I'm guessing that hoses make a better seal under vacuum than they do on over-pressure.

On vehicles that are taken apart, or came in with coolant leaks, we usually first pressure test to 20 PSIG for at least 15 min. once reassembled, then pull max vacuum (~26-27 inches) for an additional 15 min. before recharging.