Coolant Bleeding the No Stress, No Mess Way!

[Ahwahnee]

Is there a small hole in the thermostat? Some come with one, if not I always add one to improve bleeding -- but then I also use a pump to fill so the coolant is under some modest pressure.

[?Waldo?]

The thermostat does not have to be open for the cooling system to fill. The thermostat on the I4s blocks the coolant returning from the radiator but the coolant channel to the radiator is always open and the coolant return pipe from the radiator is large enough that water will flow down it to fill at the same time air will flow up it and out the radiator. If you have the van parked on flat ground, filling with the bong will bleed 95%+ of the air out of the cooling system without even starting the engine. I now do it that way and then close everything up and run the van up to temp and open the radiator bleeder until any residual air in the radiator is bled out. Then when the engine has cooled off, fill the pressure tank full and you're done.

[dkoesyncro]

How do you fill a non running engine, I got a brand new engine waiting to be started and have started to fill w/ coolant and seems as though I am only able to get coolant in the short loop, prior to open thermostat. I have even gone as far as siphon/gravity into the radiator bleed at a gallon per 2 hr. and gave up after a gallon. I do have just over 3 gallons in her but that's it. I figured thats a safe start if Im feeding it as it circulates and burps out the air.

This is an I4 w/ bleeder at radiator and heater only.

[wecm31]

[bugmanfrank]

Cool tool. But after the initial fill, I start the motor to warm up engine and get t stat open it boils over. I have tried several times. I have a 1990 vanagon with the South African 5 cyl conversion. My problems seems to have started around the time we installed the Gowesty stainless steel coolant pipes. I have found and fixed leaks, a new t stat, expansion cap, new temp sensor, new water outlet. I have wasted so much coolant I am trying to test the cooling system with just water. Any ideas?

[SCM]

[Merian]

My driveway is sloped - how much higher does the rear need to be?

[SCM]

[nekto]

this is the tool i use to bleed my JX Diesel system (86 drive train)

as you can see the essential components are a T fitting, a pressure gauge, a Schrader valve, a hose barb, and a short length of hose.
place the hose over the nipple of the expansion tank cap and pressurize to about 5 PSI. any air sorce from a bicycle pump to shop air will do. then open the bleed valve on the radiator. refill tank and repeat as needed.

it also works on the earlier style tanks with the U.S type radiator cap. (original 82 drive train)

[juanb]

Jacking the rear up is a hassle. Finding a hill that accomplishes the same thing is easy.

I do have a pressure cap attached to a bike inflator that I use for pressure testing, so that's what I use to bleed as well. The bong idea is ingenuous, but I'm going to be testing for leaks when I bleed anyway, so I might as well save the space of all that PVC tube or hose.
_________________
1989 Westy AT, 2.2 GoWesty.
We drove it to Argentina: http://www.vanenvan.com

[Jake de Villiers]

[dobryan]

Yep, love the bong concept.....for me it is a PITA to jack up the bus or connect a pressure tank (have done both those methods), just whip out my hose and stick it in the expansion tank....
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

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https://www.thesamba.com/vw/forum/viewtopic.php?t=695371

The Western Syncro build
https://www.thesamba.com/vw/forum/viewtopic.php?t=746794

[?Waldo?]

If the rear of the van is jacked up so the expansion tank is above the top of the radiator then it is definitely easier to just fill it and the bong won't do anything for you in that situation. If it isn't jacked up, it's certainly much less work to use the bong. I also find it to be less work to use the bong than to use compressed air in the way you mention. Bong is a lot less work than using a pressure bleeder. I really couldn't care less how someone else bleeds their coolant system, but I have personally jacked up the van, used the factory method (and am very good at it), I have a pressure bleeder and have used it, I have compressed air and yet for ease, simplicity, speed and no-mess I now choose the bong every time.

[tencentlife]

It's a clever device but there are two methods that are quicker, easier, and free.

One is to elevate the rear of the van ~1 foot, until the pressure tank rim is at or above the level of the radiator bleed, when both will be at about 38-40" (as you lift the rear the front goes down some since the rad is so far forward of the front axle; check with a tape measure from the floor). Then simply fill and let gravity do the work, but fill slowly in batches of a half-gallon or so to let the liquid flow into every space and avoid trapping air in some area. Close the rad bleed when liquid is coming out sans bubbles, top off the p-tank and close. I always have the back of a van elevated to do almost any work anyway.

The other is as denwood says, but simpler: van on level ground, radiator bleed open, fill the system slowly as above until pressure tank will accept no more, close with pressure cap, and give a quick puff of compressed air into the cap's nipple with a rubber-tipped air nozzle and move the nozzle away. The cap will release any pressure above 1 bar, but if you're quick, even with 100psi source the pressure won't even go above that. No need to regulate the air down or anything special. This forces liquid up and out the rad bleeder, so let it flow until it's just liquid without air bubbles. If necessary, close bleeder, remove cap, top off tank and do again. Finish by closing bleeder before re-opening tank to top off.

In any filling procedure, be sure both heater valves and the bleed valve in the engine bay are full open. 1.9's engine bleed valve is in the double hose coupler on bulkhead, 2.1's is on the t-stat cap. Leave these all open when you get the engine running, and after a drive close them off and open the rad bleed bolt one more time before putting the grille back on.
_________________
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Experience is kryptonite to doctrine.

[JunkYarDog]

Forgot to say, cost me $15. Additional items were laying around unused.
_________________
I have never owned a VW I didn't like, but there have been a few Fords and Chevy's.
85' GL Sunroof
68' Beetle sedan
72' Chevy C10 (LWB Step)
(67' Volvo 122S pending)

[JunkYarDog]

I finally made one for me. Made a few mods just because I had parts laying around.
Leak testing

External drain tube

Internal

Tube top mod to eliminate strapping it to pipe

_________________
I have never owned a VW I didn't like, but there have been a few Fords and Chevy's.
85' GL Sunroof
68' Beetle sedan
72' Chevy C10 (LWB Step)
(67' Volvo 122S pending)

[86 for nix]

I tried this on mine and was only able to get about 3gal out. I then refilled with water (just to flush, not to drive with it), using the Libby Bong as prescribed (water coming out of bleeder on radiator on level ground). So, with the system presumably full and bled, sucked it back out and still only got about 2.5 gal. I don't have the conical adaptor, but attached the suction hose via the reducer that is part of the Libby Bong.

my question(s): should that work as well as the conical adaptor, or is the suction not great enough given the turbulence in the burp tank?

should I remove the thermostat to get to the fluid behind it?

[flomulgator]

So I thought some out there might get a kick out of my particular Libby Bong

Add that to the list of uses for the venerable Voile strap.

[denwood]

If you pressurize, then no need for the bong.

My fill method is to apply air pressure at 15psi via the overflow hose on the rad cap. The cap is designed to bleed off at 15psi from the coolant side, but has little resistance if you pressurize from the overflow hose. The air can be bled from the rad, top up, and you're done. I like this as you can pressure test any work you have done while you're at it by taking pressure to 20 psi.

Cheers,
Dennis.
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Cheers,
Dennis Wood
The Grape

[rwixom]

Any reason why this wouldn't work with a Zetec (Bostig) converted Vanagon? There is no pressure bottle anymore, just a fill tower and the expansion bottle. I imagine you would connect the bong at the fill tower and follow the bong instructions? How does the expansion/recovery tank play into this?

Ryan