D6lc

Its winter here and I have a few jobs planned for the coming months to get ready for a great summer of driving next year. On the list is:
Rebuilding & painting the brake calipers
New engine mounts
Water pump replacement.
So on eth water pump replacement I am a little concerned with the re-filling of the system without a vacuum and the cycles of burping, I am concerned that with an air pocket in the system as I drive I can do alot of damage.
Anyone comment on their experience of re-filling the coolant system, either manually or if you used a vacuum system and recommendations

mmahon04

Ross,

I have done both methods, manual burping and vacuum filling, several times apiece (new water pump, thermostat, 3rd radiator installation, and aged coolant flush).

General thoughts: Doing it via vacuum bleed is safer, easier, and much much quicker. A manual bleed might take an hour+ the day of work, then several days of continual checking and topping off (to get it to my satisfaction/mentally assured). Vacuum bleeding is a 30 minute affair (I did it last night at 7PM). Vacuum bleeding is also a much more surefire way of getting all air pockets out; a front radiator, mid heated, rear-engined car has a lot of plumbing and high points. Vacuum bleeding also allows you to test the soundness of your cooling system.

Manual Burping
1) PREPARATION: Before the car is turned over but after your work is complete, fill the coolant expansion tank (reservoir) completely. Leave the cap off, and flip up the "purge valve" on the reservoir (looks like a rectangular piece of metal fitted through a plastic piece; flipping it vertically opens the valve).
2) REFILLING SYSTEM: Turn the car on (engine on), and set the heat to 'HI' on the climate controls (this opens the heater valve to allow flow through). You should see or begin seeing the coolant level drop; fill it as it falls. The level should stabilize fairly quickly (much before the engine heats up), but this does not mean there are no air pockets in the system.
3) BLEEDING SYSTEM: Keeping all things the same, replace the pressure cap on the reservoir and follow the instructions listed here. They are for a Boxster but the system is the same. At it's core, you are just trying to circulate your coolant (and any air bubbles) past the purge valve, so whether it's that exact process or driving, it will accomplish the same goal. You will most likely need to top up again after some degree of driving. Remember to flip the purge valve back down when all bleeding is done.

Vacuum Bleeding
1) TOOL NEEDED: You will need a tool designed for vacuum bleeding the system; I use the UView Airlift 55000. Doing it with this method is quite simple.
2) PREPARATION: With the coolant drained and the car off (engine off, but with the key in a 'powered' position), turn your climate control settings to 'HI' heat. Open the "purge valve" on the coolant reservoir. Fit the adapter (I use the smallest, but not tapered one) and the vacuum tool into the opening of the reservoir. You may have to push open the rear hatch a fraction more than it naturally opens and approach it at an angle to get the tool into place. Tighten the adapter into the reservoir opening for a full fit. Attach the "vacuum" attachment to the tool, and connect an air line from your compressor.
3) BLEEDING SYSTEM: Open the check valve, and run the compressor until the system reads a 25" pull. Shut the valve, and leave for a few minutes to check for leaks (the gauge will begin dropping if you have one).
4) REFILLING SYSTEM: Prep the "refill" attachment by sucking coolant into the line and closing the valve; you want the line bled before use. At this point, connect the "refill" attachment to the tool (carefully, don't want to break the vacuum you have on the current system), and make sure you have a good supply of pre-mixed coolant handy. Something around 3 gallons of distilled water and coolant to match has worked for me; I buy in bulk and mix. Put the end of the "refill" attachment into your coolant refill supply, and open both valves. The vacuum in the system will suck all the coolant in. Make sure you have either a large supply ready (i.e. 5 gallon bucket), or are ready to open and shut the valve, as it will go rather quickly and a single gallon, while handy, is not enough. The process is complete when the reading on the tool is at zero vacuum. Most likely, this will result in a bit too much coolant in your reservoir; I end up sucking some out with a baster or a hand pump.
5) TEST: Drive around for awhile, make sure everything is okay, then flip the "purge valve" back to horizontal when satisfied.

Notes: The amount of coolant lost when replacing the water pump is not nearly the capacity of the full system. Remember to use original Porsche coolant, or Pentosin G12 (now known as Pentofrost SF; I had mine shipped in through O'Reilly's).

perryinva

I just did my water pump and 160ºF T-stat, AOS, oil cooler o-rings, etc, and I bought the Airlift system, which is IDENTICAL to the Porsche one and includes the adapters for bunches of different openings. If you have an air compressor with a tank, it is the easiest thing in the world to use. You only need to install the air hose quick disconnect fitting that matches your compressor lines, like $2 at Lowes. If sucks all the air out in maybe 20 seconds or less, allows an easy test for leakage before filling the system, and with all the quick disconnect and valves included, is idiot proof to use and refills the system in like 3 minutes with no mess. I got mine on Amazon here:


And I would never burp a coolant or any other system again. It rates a 1 on the difficulty scale, it's that easy.

Correction to mmahon04's post above, you are drawing 25" Hg vacuum, not 25lbs! Also, it will likely drop a little during leak test, from 25"Hg to maybe 20"Hg, that is normal.

Hurdigurdiman

Theres a guy changes his water pump by unloosening a hose by the pump. Doing the full job. Simply tops up the coolant and burps the system. It looks pretty easy to me after seeing this video. Its a 1999 996.

Imo000

Just like in the video, I had the back up nice and high during refill. Then left the purge valve open and drove around a bit, then topped it back up and that's it.

Couple of things that shouldn't be done in that video is only using a hydraolic jack to keep the engine up. Use something mechanical like an axle stand. Hydraulic jacks can and do fail without much notice. Also, since a new gasket is used with the new pump, it should go on dry. Silicone is used if there is no gasket or an old one is re used.

perryinva

Don't take this the wrong way, Hurdi, but just because it's on a youtube video doesn't mean jack. As Imo pointed out the guy takes a bunch of chances with using a jack to hold the engine up, and you should not use sealant. If you want to cut corners because you don't want to pay the money to do it safe with the right tools, or buy a new gasket, that is of course, your call to make. But after seeing this, why would I think that just plain ol burping is fine too? Not that I'm saying it absolutely isin't. They wouldn't have a burp valve on the car if there was't a use for it. But the "correct" procedure, and one that guarantees no air in any pockets, is a vacuum fill. Like I said, no offense, and I burped systems for years, but the cooling system on this car has so many convolutions, and like the OP I was concerned that if Porsche recommends a vacuum fill, there is likely a reason, so for $105, I'll buy another tool I can use forever, (and on any car I want, or lend to friends, etc) and have total peace of mind.

Kazual99

I changed my water pump a few weeks back and the gasket requires no sealant. I have an airlift and trust me you want to use the vacuum system to refill coolant. Holding the engine up for a short time is okay in my book.... However if you search the forums you will find those who will use a jack and those who won't use a jack to hold up the engine. Owners preference

Imo000

It's not ok for any amount of time. These things fail in a hearbeat. You are in the mercy of the seals that hold the hyrdaulic oil in. Unlike a scisor jack, it has no mechanical barrier. I don't trust them and never will but I used them all the time. If you can understand the principal how they work, you would know what I mean.

BTERRY1

Thread revival and dumb question. When using the max view to draw a vacuum on the system is the purge valve opened or closed? Also is there anyone located in San Diego that would let me borrow theirs? Will provide deposit for full value till returned. Let me know. Thank you Brian.

Sneaky Pete

The purge valve needs to be closed otherwise you would never realize a vacuum. If the valve is open the cooling system is open. The Airlift is the best way but not the only way.

BTERRY1

Thanks Pete that is what i thought but just double checking. Now hopefully someone will chime in and let me borrow/rent a Uview vac.

werkzrs

ok so here is my dillema....I have the Shwaben Air evac tool....in my case i have the GT3 center radiator on my C2S and i had a small meak on it. I was able to fix the problem and so i installed everything back on....The thing is when i removed it i may have lost about 2 gallons of coolant. I was told to try to refill the radiator but that seems impossible since both feed lines are at the bottom. I tried with the shwaben tool but its not holding 25Hg of vacum. could this be because i still have coolant in the system? i have no leaks. Any help would be appreciated.

Ahsai

Have you tried vacuum it a few times? It may still have air trapped inside. If it doesn't hold vacuum, either your system is not air tight or there is still air trapped inside the system.

JTT

Sorry to resurrect an old thread but I have a question about bleeding air out of the cooling system.

I had to open a cooling line (lower line on right side rad). In the process, I lost a little coolant, although surprised at the very small quantity (maybe 1/2 cup). All is back together now, but I would like to bleed the air out of the system.

First question, can a vacuum bleeder be used to bleed once the system is already full (or nearly full)?

Second, if I go through the manual bleeding technique or running, revving , venting, running, ravings, venting, etc, is this normally done while stationary (such as in a driveway)? The procedure I'm reading calls for holding 2500 rpm for 5 mins or so with occasional repeated revs to 5000 rpm. It doesn't "feel" right to scream an engine with no load. Would it be acceptable to drive the car, stopping regularly to check and top up coolant?

ejdoherty911

The vacuum fill tool makes the job of refilling the coolant A LOT easier, and more importantly, helps verify you don't have any air leaks in the coolant system. I had a helper which I think is a requirement. After everything we needed was gathered together and ready to go the refill was completed in 5 minutes and the system was perfectly filled. I think I added one cup of additional coolant a week later to the reservoir.

I used this one: FJC 43610 Radiator Coolant Vacuum Refill Kit. $65 You also need an air compressor to create the vacuum. I had a small air compressor, 2 hp.

*** I also had the two JUMPER RELAYS that open up the front radiators *** I think that's an important part of the job. I have a 2002, C2, tiptronic.