R12 Cooling System Bleeding

S

Stuey

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Howdy,

Does anyone (David?) have a good procedure for bleeding air from the R12 cooling system? Or do you just get most of it out, and that's good enough? I basically fill the rad., run the car, top it up to the brim, then put the cap on. Then run the engine at about 1500 rpm (heater on) until it warms up and the thermo. opens, open the bleed screws in turn and release the air. That's it. It this correct?

Cheers

Stuey
 
Stuey,

They used to use a funnel with a spout around half a metre long also. I don't know how essential it was for a 12 but with the 16 series, the top of the heater matrix was higher than the filler cap which made it impossible to get all air out without it. I have seen a few home made ones many years ago & from memory they made them out of an old radiator cap & brazed a spout into it to which they connected the funnel.
No doubt someone will correct me if I'm wrong. Overseas, some even still suggest this type of funnels on Cits as a surer way of ridding the system of air.
smile.gif


Alan S
 
Yer,

similar to what we used to do with our combi camper that ran twin Rads, one up on the bull bar, one in the engine compartment.

We used a colostami bag? I think it was from the hospital. You just hang it up in the shed rafter and fill it with water, and as it's see through you can leave it there until you see no more bubbles, and she's all done
smile.gif


seeya,
Shane L.
 
Stuey,

I bleed my 16TS by hanging the overflow bottle high above the engine and open the bleed screw(s), of course after shutting the radiator cap. Alternatively, make up that extended funnel and bleed the system that way. The overflow bottle approach is neat and easy but I haven't tried it for a 12.

John

<font face="Verdana, Arial" size="2">Originally posted by Alan S:
Stuey,

They used to use a funnel with a spout around half a metre long also. I don't know how essential it was for a 12 but with the 16 series, the top of the heater matrix was higher than the filler cap which made it impossible to get all air out without it. I have seen a few home made ones many years ago & from memory they made them out of an old radiator cap & brazed a spout into it to which they connected the funnel.
No doubt someone will correct me if I'm wrong. Overseas, some even still suggest this type of funnels on Cits as a surer way of ridding the system of air.
smile.gif


Alan S
Click to expand...
 
<font face="Verdana, Arial" size="2">Originally posted by DoubleChevron

We used a colostami bag? I think it was from the hospital. You just hang it up in the shed rafter and fill it with water, and as it's see through you can leave it there until you see no more bubbles, and she's all done
smile.gif


seeya,
Shane L.[/B]
Click to expand...

Presumeably unused???
eek.gif


Alan S
 
Stuey,
Allans pretty right about the funnel, on most Renaults the radiator is lower than the heater matrix and therefore you can geta air pocket in the heater, we have an old radiator cap with a hole drilled in it and a tube welded to it coming up into a funnel and just keep the funnel full while your opening the bleed taps.
Another trick is, this is for emergencies only, when your stuck somewhere you can reverse bleed it, this is where you keep the radiator cap on tight and conect a garden hose to the expansion bottle hose, turn the tap on and open your bleed screws, this will work without even running the motor but its very hard to put coolant in, that is unless you have coolant on tap.
Seeya,
David.
 
Is this while the car's running? I still can't see how the air would get out of the heater - are the bleed valves opened at the same time? Please explain.

Stuey Hanson
 
Hi Stuey,
The following is an extract from my workshop manual for the R12:
engine & rdiator drain taps closed. Heater valve on "heat". Fill expansion bottle to abt 30mm above max mark on glass and screw down the cap/valve assembly.
Open 2 bleed screws, continue to fill system through radiator filler cap, then full clamp two hoses flat. ( Here it is hard to explain without pictures. But on the R1170, R1171 - R1330 engines the points are on a hose very close to the exhaust manifold flange and the other point on a hose which branches from the bottom radiator hose to a bleed screw. )Clamp the hoses as near to the pump as possible. Now run the engine at abt 1500 rpm and continue to fill the system through the radiator. When the coolant runs freely from the bleed screws without any air in it, close them and do not touch them from this point omwards.
Remove the clamps and top up the radiator. Check the level of the expansion bottle after the engine has cooled down.
Hope it makes sense and best of luck.
Wouter

<font face="Verdana, Arial" size="2">Originally posted by Stuey:
Howdy,

Does anyone (David?) have a good procedure for bleeding air from the R12 cooling system? Or do you just get most of it out, and that's good enough? I basically fill the rad., run the car, top it up to the brim, then put the cap on. Then run the engine at about 1500 rpm (heater on) until it warms up and the thermo. opens, open the bleed screws in turn and release the air. That's it. It this correct?

Cheers

Stuey
Click to expand...
 
Clamping your heater hoses is ok as long as you have coolant in the heater, in other words if your working on the cooling system and you havn't drained the heater you might be able to bleed it by clamping, however if the whole cooling system is drained totally you will need to bleed it the way I suggeated earlier.
If you use a funnel you need the motor running to pump the coolant though and pump the air out, especially though the heater core, if your reverse bleeding you don't need motor running because the hose will supply more pressure than a water pump ever will.

David.
 
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