Coolant Bleeding the No Stress, No Mess Way!

[insyncro]

I have been pressure filing the cooling system.
Raise the front end with rad. screw open and push fluid from lower rear tank forward until no bubbles from upper rad. screw.
Use a garden setup as previously mentioned or pressure filling kit from Snap On or Mac Tools.
Close upper rad screw.
Lower front of van.
replace coolant tank cap.

Haven't need to bleed doing it this way.

dylan

[t_man]

I used my friends Libby Bong this evening. All went well this time. I did have some issues my first attempt. I don't think the thermostat ever opened (it was a cool day??). So the bong sat there, very full. I kept checking the radiator bleeder and no fluid. After 5+ trips back and forth, the bong eventually fell over. I concur that you need a secondary support to keep it up - a bungee cord over the back bumper worked for me... or you could simply ask a friend to help. Live and learn.

I did drive around for awhile (20minutes) and noticed an air pocket develop in the top of the pressure tank. I got spooked, drove home and turned off the engine. I went around back and it was full again. Note, I didn't add any coolant to the reserve tank, yet. It's really filthy and needs cleaned.

Should I add some coolant to the reserve tank and hope for the best? Or load another Libby Bong?
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-tgc
'90 Westy Automatic

[GriffithBuilt]

Just built one of these today and used it to bleed/fill my coolant system. Will still need to hook it up again with the vehicle running to get any of the other bubbles out of the system, but initially it worked great. Used some zip ties to hold it upright to the fasteners on the inboard side of the rear quarter panel (not sure what they were for initially). Worked great. I did use the electrical tape and also put some RTV around the connection of the nylon hose to the 2" pvc pipe.

Bled the system through the top of the radiator till no bubbles then checked at the return line upper petcock (subaru conversion) and just had fluid, no bubbles. I had pressure bled it a bit before so I think that line was near full prior.

Jason

[Perales]

Just a thought.
Would it make any sense to drill out an old reservoir cap and epoxy it to the pipe rather than using a PlumbQuick connector?
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-- 1987 Westfalia automatic (Captain Vino)

[simd0ggie]

Thanks Andrew! This made it so easy, I think I only dropped about a cup of coolant on the ground! Awesome.

I love the fact that the drain tube also serves as a sight tube.
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-Matt
'85 Westfalia w/EJ25, '14 Tiguan R-Line 4 Motion

"There are two possible outcomes: if the result confirms the hypothesis, then you've made a measurement. If the result is contrary to the hypothesis, then you've made a discovery.”

[DAIZEE]

Well today I was told to look up Libby's Bong and I did and I think it will make life easier for me to bleed my coolant system. It has managed to drop my anxiety level markedly.

I like'd the pressure thingy too but it required more equipment and it is bulkier to store than Libby's Bong. I guess I'll have to make a trip to Home Depot.

THANKS to the Sambanista who told me to look for it and thanks to Libby for the creation and sharing it with us all..
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'09 2.5L Jetta 5 cylinder, 5 spd, super turbo, see thread in H2O Cooled Jetta, etc...
83.5 Vanagon L Riviera Model with 98 1.9L TD AAZ 4 speed Daily Driver 3 out of 4 seasons (sold)
84 Vanagon GL Wolfsburg Westy WBX 4 speed (sold)

[DAIZEE]

Andrew at the end of your procedure you said "burp the tank". What do you mean? I'm sure it will be real obvious when you explain it

How long an ABS or PVC (2") do you need? and with only one person doing this after the first part, you close the rad bleeder, rev the engine and then bleed again? Does reving with the bleeder closed move the bubbles forward and upward? I'd probably do this a doz times to make sure I never have air again
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'09 2.5L Jetta 5 cylinder, 5 spd, super turbo, see thread in H2O Cooled Jetta, etc...
83.5 Vanagon L Riviera Model with 98 1.9L TD AAZ 4 speed Daily Driver 3 out of 4 seasons (sold)
84 Vanagon GL Wolfsburg Westy WBX 4 speed (sold)

[J Charlton]

Libby's Bong - a real nice piece of innovation byAndrew. There are no "buts" here - a few principles of physics however.
1. Any liquid will absorb a gas - (well most liquids anyway). In our application we're taking about water absorbing air - the air is in solution in the water (that's why fish can "breath" - their gills can remove the oxygen from the air in solution in the water and transfer it to their blood).
2. The ability of a liquid to absorb a gas varies inversly with the temperature of the liquid - hotter liquid, less absorbtion - eg. put a bottle of coke in the fridge, let it get cold then open it - very little "frothing" - take another bottle, put it in the sunlight, let it get good and warm and then open it - what happens - its probably all over you - that's the gas that has been dissolved into the liquid (the coke) - C02 - carbon dioxide has been disolved into it that is either staying disolved in the cold coke or frothing out in the warm coke
3. The ability of a liquid to absorb a gas varies with the amount of pressure the system - gas and liquid are put under.

There's more - but this should do it for this - the Libby bong works by being able to supply a constant supply of new coolant to the system as the system warms up (gas - air - is released) and the pressure tank gets gas from the system - gas is also released from the top of the rad until you close it.
The beauty of the bong relative to a pressure system is that a pressure system will force air into solution in the coolant whereas the Libby bong will not. Hot coolant - one rev's the engine to ensure that the thermostat is open and that hot coolant is circulating - is under a degree of pressure - there's no where for the gas in the system to be released - the hot coolant would like to "give it up" until it gets back to the pressure tank, with the "bong" attached - there the gas can escape and be replaced with coolant. After a period of time circulating hot coolant, ensuring that there is no "bubble of air" at the top of the rad, all the coolant in the system will have given up its absorbed air at the pressure tank - the system is free of absorbed air, cap it off and as the coolant cools off and reduces in volume, it will suck replacement fluid back from the overflow bottle. If there's no air available for the system to absorb then you have a cooling system truly "bled" of air.
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[DAIZEE]

how can you tell he's a retired physics teacher? and even more than that. I certainly understood that explanation.
_________________
'09 2.5L Jetta 5 cylinder, 5 spd, super turbo, see thread in H2O Cooled Jetta, etc...
83.5 Vanagon L Riviera Model with 98 1.9L TD AAZ 4 speed Daily Driver 3 out of 4 seasons (sold)
84 Vanagon GL Wolfsburg Westy WBX 4 speed (sold)

[240Gordy]

I thought the bong worked by simply getting the supply side of the coolant loop above the top of the rad, thus letting gravity (from snowmaking class I think it can be refered to as "head") push the coolant over the top, and the coolant will push the air out, since the engine is cold, the coolant won't dissolve any air. it just gets pushed out at the rad and the bottle.

it seemed to work okay cold.
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Tencentlife said,
"So, now that you know what you're doing, go to town."
2010 GOLF TRENDLINE 2.5
1985 GL now with more! a 2.1L
H&R SPORT(RED) Springs FRONT , SLAM SPECIALTIES RE6 AIRBAGS REAR

[randywebb]

I thought that dissolved O2 was measured in ppm.
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1986 2.1L Westy 2wd Auto Trans.

[DAIZEE]

but by heating the liquid do you release more air and you need to do this because the liquid is going to be heated by the engine and if there is still air suspended in the cold liquid then it will be released when that cold liquid becomes hot and then you'd have all that air and then you'd have to bleed it again.

mmm why can't I say things as clearly as others. Possibly because I have a mental block when it comes to physics, barely scraped thru it in college. Anyhow that's my story and I'm sticking to it. i.e heat it up and get as much air out of it as possible.
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'09 2.5L Jetta 5 cylinder, 5 spd, super turbo, see thread in H2O Cooled Jetta, etc...
83.5 Vanagon L Riviera Model with 98 1.9L TD AAZ 4 speed Daily Driver 3 out of 4 seasons (sold)
84 Vanagon GL Wolfsburg Westy WBX 4 speed (sold)

[Wildthings]

The system is quite capable of getting reasonable amounts of air out on its own. If you have a normal operating system and somehow get a quart of air into the coolant hoses the system is going to self bleed once you start the engine and the coolant begins to circulate. Same with any air dissolved in the coolant, the system is just going to purge the air as the engine runs and heat cycles.

You certainly don't want to start out driving with a gallon sized air bubble in the engine or radiator as that is too much for the system to handle, but a pint or quart sized bubble just isn't going to be that big of a deal. If you have allowed a small amount of air into your system somehow all you usually have to do is check that you have sufficient coolant in your overflow tank to replace it and then drive as normal. Follow by checking the overflow tank level again once the engine has been driven a bit.

[DAIZEE]

I've finally got all the components to my Libby's Bong. I'm excited about it and it seems to be a stress reducer for me. I had to buy 20 ft of the 1/2" OD. So anyone near me needs any hit me up. I'm sure it will be useful for other applications as well. Now I just have to get my van back so I can test my rig. Thanks

I've brought this up so that any newbies, et al can see some options for any coolant questions. There of course is much more.
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'09 2.5L Jetta 5 cylinder, 5 spd, super turbo, see thread in H2O Cooled Jetta, etc...
83.5 Vanagon L Riviera Model with 98 1.9L TD AAZ 4 speed Daily Driver 3 out of 4 seasons (sold)
84 Vanagon GL Wolfsburg Westy WBX 4 speed (sold)

[Orbitald]

Another satisfied customer!

Thanks Andrew!
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'87 Syncro Westfakia, 1.9TD ADE (AAZish), 068 Injection Pump, K03 turbo, 2.5" exhaust, Mercedes nozzles, SAAB Blackstone charge-cooler w/ 800cfm fan, Micro-1000 EGT sensor pre-turbo, boost at about 13psi, 235/70/16 with stock gearing

[greenplasticme]

Built the libby bong, attached it to coolant tank (the one with the sensor) and i couldn't get a good seal.

I tried duct tape around the coolant tank cap threads and putting the rubber fitting over the top and tightening down the clamp. Coolant leaked out lightening fast.

What did you guys use to get a good seal?

The coolant tank cap thread hole isn't perfectly round; it's slotted to work with the pressure cap.

[Jake de Villiers]

[greenplasticme]

Yeah, right sized rubber reducer. The thing is, and I wish I had a picture, that the hole to the tank is not a complete circle. It's a circle in that it's round, but the threading is unusual. There are two tabs that stick out on opposite sides and this is used to connect the pressure cap to the tank.

[crazyvwvanman]

You have the early 83 wbx tank then. The libby device is not designed for that kind of tank and those are rare enough that most people don't know there is such a thing. Same tank was used in all 83 diesel vans but only a few 83 wbx vans.

Mark

[blackglasspirate]

I don't think I've seen the slotted cap, so I can't help there, but I use teflon tape around the threads.
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'87 Vanagon GL Westfalia
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