Question on Coolant Filling with Uview Airlift

I am getting ready to refill my coolant after replacing the water pump. The Uview manual recommends that the entire coolant system should be emptied before pulling vacuum. Is this necessary? I wanted to check before I do anything that I will regret. Thanks!

I didn't even both with the vacuum. I just refilled and lifted only the back side of the car up at and angle to allow the air out. Done this with every car and never had a problem.

Can you elaborate Maor? I was thinking of doing the full coolant flush later this year. I know that there is a purge valve on the coolant reservoir, but I was not sure how will you get all of the air out of the system without doing the "vacuum fill"? Do you just keep filling up the coolant tank as WP pushes the coolant to radiators?

Quotes source post: 11028498

+1

To answer your question, it should be fine to draw the vacuum with the system partially filled. It's essentially the same situation you experience after you begin filling the system with the vacuum applied. Just make sure the reservoir is empty initially to avoid pulling liquid into the vacuum system.

I pulled vacuum 2 or 3 times to draw coolant towards the engine drain. Vacuum + drain, vacuum + drain, then draw vacuum and refill. Dont forget to turn the heat on max to open the heater core up. I used a new Home Depot homer bucket on a stool to elevate the coolant and make sure its always got fluid in it above the pickup. Once you use the Uview to fill the coolant system you can never go back. I use it on all of my other cars as well. The previous comment about lifting the car in the air is garbage. It will take forever to bleed out and get up to temp. Uview is the right way to do it.

Thanks for the responses folks! Much appreciated.

The lifting method not garbage! It does the job well and doesn't cost a dime.

Would someone please provide info on what the lifting system entails? I will need to partially refill my system in a few weeks after some radiator work. TIA

This is what I did with my '99 996, might not work for a Cayman: Lifted the rear bumper to about 3ft. Removed the coolant cap and re filled it until it was full. Then started the engine and kept refilling untill it didn't take any more coolant. Then I replaced the cap and opened the venting valve and let the engine run until it came up to operating temperature. Then I shut the engine down and let it cool down. After the engine was cold I removed the filler cap again and topped off the coolant and then re installed the filler cap. After all this, I lowered the car to the ground and went for a spin. After the test drive I closed the venting valve and let the engine cool down again. The coolant level was normal by then. Next morning I re checked the coolant level and thats it. Since I was working in the engine for the last few months, I wasn't in a hurry. This all can probably done in fewer steps than what I did.

Thanks Imo, I have an '01 C4 that I will be removing the radiator from, so this might work. I think I will also look at the vacuum tool that is mentioned as well.

So, Imo000 it sounds like the coolant refill procedure is almost identical to the conventional front engine cars and you can avoid messing with the vacuum tool. It is good to know.

AK, this is accurate. The vacuum tool merely helps ensure that the complicated (engine in the back, rads in the front, lines in the middle) system gets evacuated. If you have patience and 5 or 10 degrees of slope, you can accomplish the same thing without the $100 tool. Having used both methods, meh. I think the tool is valuable for pressure-testing the cooling system, but if you've got a little time and some gravity, you have everything you need.

So which way would you recommend on a car that has had no engine in it for a few months and probably has had all the coolant leaked out of the radiators and plumbing?

Use the tool. While not using an airlift is "free" you end up running your car for 20 minutes to get it up to temp enough to open the thermostat and get all the bubbles out. In the meantime you have coolant surging in and out of the resevoir going all over your garage floor. Yes you can do it, but the Airlift - which is $120 saves you a messy clean up, ensures the system is bleed 100% right, and you dont have to watch your car idle for 20 minutes or more as air pockets develop all over the cylinder heads which are already fragile pieces of **** on a 996. What the hell do I know? Im just a former 996/7 owner. I'm in ATL, you can PM me when you want to borrow mine.

The heads are not gong to crack from air bubbles during idling. There is very little stress on an engine at idle. Things go wrong when under load and cooling is comprimised. Yes the way I aproached this was like any other car, get the angle to get the air out. Water drains downhill so then it pushes all the air out where it drains into. That and with some heat cycling, it purges the system of air. Had a FWD project car where the front end had to be lifted 3 ft to get the air out of the heater core.

Quotes source post: 11032036

You sure about that? This is Rennlist we're talking about. Just the fact that this topic has gone past 1 page and betting it will hit 3 pages of discussing two options that could've been covered within 4 posts max.

Oh, crap! I think I might have used the wrong kind of vacuum. I used 5W30 vacuum?!?

I agree with Maor and IMo00. Why spend a lot of $$ on fancy tools when you don't have to. My lazy spend thrift neighbor has spent a lot of $$ on an electric compressor. lines, air-chucks, etc... just to put air in his tires and run air tools. When my tires get low I just pull out my trusty "Golden Rod" air pump and 50 or so pumps later, depending on whether it is down 2 or 3 psi, the tire is up to pressure. My kid hates it when I need to run air tools. I have an old water tank that he has to pump to 100 psi. I put him on the pump until the job is done. It only takes ~2 hours to get it from 10 psi to 100. After that if he jumps right on it when it sinks to 80 psi or so it only takes ~30 minutes to get it back up to pressure. An added benefit is that this has taught him to be self sufficient. After the last time running air tools, whenever I mention air tool related work he disappears into the woods for weeks at a time. I think he lives on squirrels, nuts, moss and tree bark or something. Anyway my point is both methods work fine. My way just saves $$ and teaches valuable life skills.

Funny, I know guys that will not work on cars without air tools. I know guys that will not even wax their cars without a random da orbital polisher.

Quotes source post: 11032293

Their kids must be in good shape.

Quotes source post: 11032278

LOL- Outstanding

I have air tools but stopped using them. Only use it to pump up the tires. There is no feel with air tool. If a bolt doesn't want to come out, I use an extension to get more leverage but can still get a feel for what is happening. Mechamics use them to save time because time is everything for them.

The Airlift is a great tool for any cooling system. When you buy the whole kit on Amazon, you get all the fittings for virtually any car. It is great for checking system integrity first, rather than filling it laboriously, and then finding the leak. But then, I don't even work on my car unless it is up on my lift, no PITA jackstand crap for me anymore. If you can afford it, it is a great piece of kit worth every penny, IMHO.

Quotes source post: 11033476

Damn, there goes $120......

So to wrap up this thread, I ended up using the Airlift tonight to refill my coolant. It was super easy - easier than I thought. I highly recommend it. Keep in mind that if you plan to buy one, you will also need a compressor capable of 90 psi. You can get a decent compressor at The Home Depot for $100 or less.

I plan on doing my water pump soon, 3 feet is a long way to lift the rear end, pretty damn high. but if it works, it works

Quotes source post: 11046830

I'm pretty sure you could get away with ~2' 9 1/5".

Quotes source post: 11047572

My tape measure only has ⅛" and 1/16" increments, which should I use . . . . . Seriously though I've got the Uview and am getting ready to do a flush. Are you guys saying the rear should be lifted with the Uview set up as well? I thought the vacuum automatically overcame any trapped pockets of air.

Quotes source post: 11048141

No, with the uview tool, the car can stay flat on the ground. Also, the container that holds the new coolant can also stay on the ground even though that's lower than the reservoir. The vacuum does all the work for you.

Correct, vacuum pulls out all the air, so no air to make pockets. In fact, the only drawback to the Uview (besides price and needing a compressor, with a resevoir tank) is that if you have bad/soft hoses they will collapse in, under the vacuum, which I suppose can weaken them. It is very fast and clean to use. The instructions seem confusing, unitl you do it, then it's "OH, that was easy." There is JUST enough clearance under the hood.

Preparing to add 3rd radiator on my 981CS and will use the vacuum tool for the refill. Is it necessary to open the bleed valve when using the vacuum tool? Accessing the top of the engine in the new 981 is a PITA and I would be happy to avoid this step if even possible.

No.......I didn't do that when I used mine but you need to burp the system with the bleed valve when you have the system full. I ran around town a couple days with it open.

After several hours of forum research I realized the burp step is unavoidable. I tried like hell today to reach up from underneath the car to access the bleed valve d-ring.....no luck. I will be disassembling the interior for access. No big deal....all fun stuff.

I'm in the process of doing cooling stuff on my 2005 997 C2. I'm dealing with the whole Mt. Vesuvius of coolant as air tries to get out. So I decided to buy the airlift vacuum system. Question, though. What happens if I draw the vacuum on a system that is likely over half full? Is this OK? Also, do I put it on the reservoir where the blue cap goes? Or the pressure relief cap (square wire thingy next to the blue cap)?

Quotes source post: 13393610

Put it on the blue cap opening. I've never tried pulling vacuum on a partially filled system but I've heard it will work too. Let us know how it goes.

+1. Blue cap. Should be no issue drawing vacuum on partially filled system.

I saw this thread that sounded like the same thing but it wasn't *exactly* the same so out of paranoia I'm asking for myself. I put on the airlift vacuum and it got to almost 20 psi, then it dropped suddenly to 10-15 psi, spitting a bit of coolant. And just stayed there while attempting to draw a vacuum. It showed no signs of increasing. Just spitting (needle bouncing rapidly between 10 and 15 psi) the whole time. If I stop it, it holds a steady vacuum of ~13 psi , so I don't think there's a leak. It's almost like a seal opens at 15-20 psi and then closes again. I don't know. The directions said some cars might need a hose clamped off to get the vacuum but I'm not seeing anything like that. HELP please.

Our cooling system is completely sealed below the blue CAP neck so there are no hoses to clamp. When using the airlift, it should not suck any coolant out and if it does, you need to drain the coolant to make sure the airlift nozzle is NOT touching the coolant surface and start over.

I think it's just my wimpy air compressor. The airlift box says "at least 90 psi" but I'm pretty sure it's a cfm issue. Mine only does 5 or 5.5 cfm. After an hour I manged to get it down to 21 psi (or inches of water -- what ever the units on the gauge are). I filled it from there and took a test drive. Oil temp seemed normal after a little spirited drive and no Mt. Vesuvius of coolant like the last time I drove it. I'll let it cool down and see if the reservoir needs topping off.

Reviving an old thread here....How long should it take to pull a vacuum? Are we talking seconds or minutes? I am so far not getting much vacuum and for the life of me can't see a reason why....Car came out for cam pads and a variety of other things including new coolant tank etc. Anyway, just curious how patient I need to be waiting for vacuum to pull or if I need to go and find a hole....thx

Quotes source post: 20307376

If the system is sealed up then it should hold a vacuum and negative pressure climbs quickly, within seconds. Sounds like there's an opening somewhere.

It should really take no more than 30 seconds to get to 20" and then another 30 seconds to get to 25" or so. Once you close the vacuum valve, it should hold vacuum. If it doesn't you have a leak. The hoses should be collapsed at vacuum. If you have a pressure rig, you can always try to find the leak with pressure on, but it's something that you touched during your work. One other trick I have found is that after you fill is to do it a second time. Once the vacuum is taken off, you'll find that the coolant level goes down and it might be low in the tank. I then put the vacuum back on, but with the valve throttling and will pull a smaller vacuum like 15" or less, it won't discharge coolant, just pull any additional air out of the system, and you can load a little more coolant in the system. Here is a video I did recently. You Tube

Thx all, I found the culprit, I missed a hose but at least it�s terribly inaccessible behind the coolant bottle LoL