As i recall there is a traditional burping method in the service manual

So here's the water pump that gave me problems. Sort of interesting. It looks like the shaft wore out (possibly from serpentine belt tension always pulling upwards?). This allowed the impeller to get off center and actually start wearing out the inside. Ultimately started eating away at the edges of the impellers.I'm hopeful that was a slow gradual process generating finely sized particles that flushed out easily. I'm surprised I didn't have any smaller occasional leaks before it went really bad on my last trip. When I got it home on the trailer, removed the bottom cover and took a look to see where the leak was coming from it was obvious it was the shaft. Water was pouring out the back side and down the back of the pulley.



The job itself wasn't too bad. Couple hours of sweating and cussing. Biggest headache for me was the top bolt on the pump. Frustrating because it was the easiest to see but with the pulley having been pulled upward it had worn off some of the bolt head and was jammed against it so tigthly I couldn't get a socket on it. Finally had to use an open end wrench which worked but was slow.

So parts have been replaced today. Tomorrow night I get to use that new Air Lift system to refill the coolant. Got a good deal on it with quick and free delivery from Tooltopia.com. Not affiliated - just a satisfied first time buyer from them.

but the play in the shaft wasn't that much. I think the blades are made a bit too tall and when the pump is first installed it is spun by hand, maybe backwards, so the impeller edges abrade and have just the tiniest gap/space between the impeller and casting to make the pump as efficient as possible.

The bearing wears out because of the pull/tension of the belt and the fact the seals can allow a bit of coolant past. This is what makes using the right anti-freeze I think critcal to the water pump's longevity, that and the occasional drain/refill.

Now in your car's case that the water was gushing out so the shaft probably had enough play that the impeller could have been contacting the casting more. It would have been interesting to measure the height of old pump's impellers and then the height of the new pump's impellers to see what the difference (if any) was.

Sincerely,

MarcW.

UV550500? Let us know how well it worked?

This is the one I got. UV550000. Very substantial feel with all brass connection. It was only a few dollars more than the plastic one. It was the first time I bought from Tooltopia.com. Very satisfied with price - no shipping or taxes. And tool arrived in 3 days!!

[www.tooltopia.com]

I was a bit nervous about how well it would work. I've been on tours in the mountains where a Boxster suddenly has issues with trapped air bubbles and it's a real pain to burp on the side of the road! I was very pleasantly surprised how easy this unit worked. Just screw it down on coolant tank , pull the vacuum, stick the fill tube in a bucket of coolant and it's done in minutes!

Is that tool essential? IOW, you can't replace the coolant without it?

Also, did you drain the entire system to replace that pump? Mine was replaced two years ago and here I go again. Coolant just pouring all over the place.

Thanks.


PS I have another post where I asked about removing the passenger seat and disconnecting that electrical plug in case you see it.

it involves running a hot car on a lift regularly while opening an air release valve and revving the motor - sounds complicated and difficult for one person.

Grant

...real pain in the neck. I watched Pedro and Stefan do it to a car at BRBS several years ago. Luckily they were at a gas station and were able to keep refilling jugs of water each time the system "burped". It's not really difficult - just time consuming and messy. My second experience was when traveling with a local group of Porsche's on a tour. We were on the Blue Ridge Parkway and detoured to the top of Mt. Mitchell. The added elevation made a small bubble expand and block a passageway resulting in the infamous "spewing of coolant" out the bleeder valve and all over the pavement as soon as he stopped the car. Owner had that "Oh my God!!" look until I could explain what happened. We refilled the coolant tank and got the car off the mountain and then proceeded to burp it. We had that car nose down in a ditch, doing the revving thing, watching the temp gauge go up and down, people running back and forth with refilled jugs of water from a nearby house, trying not to make a mess in his trunk!. Just very inconvenient. With one last billowing spew of coolant, steam and air it finally just sucked in all the water we could feed it and settled right down. Drove fine the rest of the day and to this day I'm viewed as "that mechanic guy" when I see him. Just goes to show how much technical knowledge you can gain over the years reading this forum!

My biggest concern and the reason for using the Air Lift system is that you can have bubbles in your system that do not manifest themselves immediately. They seem to do it at the worst possible time. I just wanted to make sure I reduced that possibility as I pretty frequently make those trips up to the mountains.

I did wind up draining the entire system on Pedro's advice. Wasn't that much more effort while I was in there.

What type of new coolant did you use? Also, dies the water pump use only a metal gasket or is sealer involved?

...on stands, etc.

Grant