Confusing coolant filling instructions

[getunder]

Reg. 01-07-85 Dg.Petrol engine. After reading the coolant instruction Wikis and others I approached filling my van with coolant with trepidation. As someone postscripted it "What a Pavlova". First task was locating the engine bay bleed screw as instructed. Despite a picture of it in my Haynes Manual I cannot locate it. some guidance please. The top of the radiator stands at 97 cm and the top of the header tank stands at 72 cm a difference of 25cm which means we are trying to get water to run uphill to fill the radiator. The instruction to raise the FRONT of the van makes it even more uphill. Logic tells me that if raise the REAR of the van by over 25 cm and fill it, liquid by the laws of physics should run out of the top of the radiator with perhaps a bit of tube squeezing due to valves, bends, air locks etc., I know life is never so simple so I am sure there are some with my simplistic diagnosis. Has anyone done it with a Registration later than mine ? (Ist July 1985.) and any suggestions.

[Grun]

Reg. 01-07-85 Dg.Petrol engine. After reading the coolant instruction Wikis and others I approached filling my van with coolant with trepidation. As someone postscripted it "What a Pavlova". First task was locating the engine bay bleed screw as instructed. Despite a picture of it in my Haynes Manual I cannot locate it. some guidance please. The top of the radiator stands at 97 cm and the top of the header tank stands at 72 cm a difference of 25cm which means we are trying to get water to run uphill to fill the radiator. The instruction to raise the FRONT of the van makes it even more uphill. Logic tells me that if raise the REAR of the van by over 25 cm and fill it, liquid by the laws of physics should run out of the top of the radiator with perhaps a bit of tube squeezing due to valves, bends, air locks etc., I know life is never so simple so I am sure there are some with my simplistic diagnosis. Has anyone done it with a Registration later than mine ? (Ist July 1985.) and any suggestions.

getunder,
A lot of folks have followed These instructions with success.
Known as 'Doing a Mocki' by one of our members who had a lot of coolant system problems.

Mike

[Ian Hulley]

When your van was registered should tell us but it could've been swapped or be borderline chang-over year or anything. Have you an early or later cooling system ? i.e. is there a plastic thermostat housing at the front left of the engine when viewed from behind and above OR is it a mekal one located bottom left ?

On a late system the bleed screw is on top of the thermostat upper housing and it bleeds air into the bleed ring around the engine bay and into the header tank. I've never had an issue bleeding our (late) system but on our drive the @rse-end of The Bus is in the air and it bleeds very easily.

Ian.

[Grun]

As Ian says,
If you have a later cooling system...........I have just found a photo in the Haynes in which you can just make out the bleed screw.
Page 0.6 Roadside Repairs........ bottom picture........ work in 55mm from the top left corner........and there is the plastic thermostat housing with the knurled bleed screw just forward (up in the picture) of the small hose.

One of the USA sites devoted to the 'Vanagon' recommended the 'bottoms up' bleeding procedure.
Cheers
Mike

[R0B]

where did this raise the front of the van malarkey start.its tosh...

[jaylo264]

Not sure i agree , as it seems logical to me to avoid air locks in the radiator if at all possible .
I`ve followed haynes and lifted me front up twice now , with success .
jaylo

[R0B]

done both of mine without raising the front.no probs.

[ermie571]

Front up...several times....with success. Keep revs up and keep gently topping up until water runs out the bleed screw in the rad.When it does, cap on the back, rad screw done up, engine bleed shut, drop revs to idle. Let idle for a min, release air from rad. Stop, allow to cool a while. Repeat. Repeat until no air coming out of rad.

Worked me me, several times


Emma
x

[kevtherev]

I used the mocki method too and no drama with it

[getunder]

Thanks Guys.Sounds to me that it can be done rear end up, bottom end up and even level. Got about 12 litres in with rear raised but did not run it until thermostat opened. Attached some hose to the plastic box cap and blew down it to pressurise it and to push some water through.Then went for tried and tested and "did a mocki" and raised front end. A bit alarming when running engine for what seemd to be for a long time and water level rose slowly probably as it got hot and spilled a little over exhaust, I stink of anti-freeze.Then suddenly thermostat must have opened and I was able to wop another 3 litres in. Water was then coming from the radiator bleed screw. By then it was getting dark and I was a bit dry mouthed with apprehension. I am using water first to check the system after changing corroded metal pipes for plastic.Just as well as I would have spilled a fair bit of the expensive " Blue Juice".Incidentally what date and engine number did the "change over" occur. Often mentioned but never documented as to what the changes were.To be continued... busy tomorrow elsewhere.

[Simon Baxter]

Jacking the van up is a load of "Balls".
I have cooling systems apart weekly, never, ever, ever in 4 years of doing this full time have I had to d!ck about with ramps.
There is science there, but it's making the job harder.
If you want to jack anything up jack the back and make the filling point higher than the top of the rad, but really, honestly, truthfull there really is no need.
Jacking the van does not reduce air locks, there is syufficient flow there to push air pockets out to the top of the system.
If filling a toally empty system then remove the bleed screw in the rad as you fill, that way you fill it up from the bottom.
Once you can't get anymore in start it up.
Fill some more till no more goes in.
rev it to 2000rpm and you'll see water p!ssing out of the rad so put the screw back in!
fit the header tank cap.
Then keep it revving, a few good hard revs every now and again won't bother it.
rev as you fill.
gauge comes up, fan comes on, blead it again, top it up and done without a jack in sight!
Customers at my garage will know how long it takes, 20 minutes max, they watch me and wonder what all the fuss is about!
you will have no problems if your cooling system is in good order, it will bleed really quickly if the header tank cap is in good order as your using cooling system pressure to push the air out of the bleed screw.

think of the cooling system as a big capitalU you fill at the top of one end of the U and the bleed screw is at the other tip of the U, obviously as you fill air will get trapped beneath the bleed screw, you seal both ends (like screwing the cap on) then increase the pressure of the coolant then you can just crack off the bleeder and air will come out.
Obviously you get to a point where you have blead a big enough volume of air out that you need to replace the lost volume with something, thats when you remove the cap and tip some more coolant in.
Another trick here is to connect the pipe to the burp tank, as the volume of air is lost you will get a bit of negative pressure above the coolant in the header tank that will be sufficient to open the valve in the header tank cap and it will draw coolant from the tank behind the flap.

It really isn't rocking horse science and the big drama that it has been built up to be.

Run till fan cuts in, if your dash, wiring and senders are all in good order then that should happen when the needle just passes the LED.
Take it for a thrash and bring it back, leave running and get the last dribbles of air out.
Fill the burp tank up till no more will go in and after a few days you will find that the coolant will find it's own level.
Any air that makes it way out of the header tank end will get expelled through the header tank cap >> pipe and into the burp tank.

pi$$ easy and not a jack or ramp in sight!

Tell me, when your central heating is playing up do you jack one side of the house up to bleed the radiators?
Thought not...

[getunder]

Simon. Super demystification. I just knew there had to be a simple answer to it. The VW production line would have ground to a halt going through all that palaver.Sounds like a good Wiki to me.

[getunder]

Haynes Manual. HE say jack up front of van. Verily HE hath spoken. HE Gospel.

[ermie571]

Noooooo Haynes not gospel....Haynes GUIDANCE. There have been some errors over time....

Em
x

[getunder]

Re. Coolant choice. Just spotted the Link on the coolant Wiki.