Fiat Panda 1000cc air lock in coolant. - AllTorque
I cant refill with coolant without air locking. The system will only take 3 litres out of 5 initially and when i run the engine, it just boils and overflows(cap left off).
Can anyone offer any advice please?
Fiat Panda 1000cc air lock in coolant. - Pete
The following assumes that the thermostat, head gasket, radiator, water pump and heater control are in good order.
Drive front wheels up onto car ramps.
Move heater control to full heat position.
Open bleed screw in pipework just forward of heater unit.
Open bleed screw on radiator.
Fill slowly with water/antifreeze mix to just below top of expansion chamber, observing bleed screws and closing as required.
Run engine at tickover for short period with cap off, not up to full heat. Top up if required.
Cap on, off ramps, leaving heater on full heat, round the block, until heater giving heat, check level again.
Close heater control, check coolant level over next couple of days.

I have two Pandas and an Uno, all 999cc FIRE types and the above works for me. Please let us know how you get on. Usual caveats apply.
Rgds.
Fiat Panda 1000cc air lock in coolant. - henry k
My Uno with 999cc FIRE engine does not have the bleed screw by the heater so I eased off the hose to the heater instead. Note the heater stubs are plastic so go gently with the pipe removal.
Fiat Panda 1000cc air lock in coolant. - jc
I owned a Panda 1000S for five years and never had trouble getting air out;put the heater on full hot;run the engine at about 4500-5000 rpm for a couple of minutes,you'll feel the return hose get hot.Also check that the air bleed hole or groove on edge of the thermostat is not blocked.
Fiat Panda 1000cc air lock in coolant. - jc
Another thought;check that your return hose(the one that is connected to the radiator hose not the manifold) is on the upper connection on the heater-if it isn't you'll have an awful problem getting air out.
Fiat Panda 1000cc air lock in coolant. - Another John H
I would say Pete\'s reply would cover most instances.

One occasion I had to take the battery out, remove the top hose from the heater matrix, and fill down the removed tube until it came out of the top of the matrix - then quickly re fix the hose.

I suspect in that the the water pump was a bit short of enthusiasm ( or blades ).

Regards

ALT John H
Fiat Panda 1000cc air lock in coolant. - AllTorque
Thanks for the tips.

The Haynes manual shows no bleed points (about as useful as a UN resolution on this subject). On inspection, I have found a bleed valve actually on the hose going to the heater matrix, tucked behind the air cleaner box - how you use this when things are hot puzzles me. And also on the left engine top side of the radiator, where is a small plastic wing-topped plug - I daren't pull it out in case it breaks! Is that a breather?

Beginning to think an old air-cooled Beetle is a good idea.....

Does anyone know if the bits I've mentioned are useful in trying to replace the coolant without air-locking, and if so, do I use them when filling the system initially or when it's been run for a few minutes (before it's very hot) to circulate things?

Thanks for your help - greatly appreciated.
Fiat Panda 1000cc air lock in coolant. - Another John H
Quote

"Does anyone know if the bits I've mentioned are useful in trying to replace the coolant without air-locking, and if so, do I use them when filling the system initially or when it's been run for a few minutes (before it's very hot) to circulate things?"

Yes.

Those are the bleed screws Pete was refering to in the second message in this thread: they both unscrew - lefty loosey :-)

- follow his instructions.


Regards

ALT John H
Fiat Panda 1000cc air lock in coolant. - jc
You won't overheat with air in the heater but with air in the rad,you certainly will.The rad bleed screw needs to be undone about 6 turns it has a groove in it to let the air out-if it breaks,the end will still block the hole but you won't get any air out thro' the header tank due to the design of the system-it must be bled thro' the rad.
Fiat Panda 1000cc air lock in coolant. - Railroad
The fact that the thermostat is closed is what prevents cooling systems bleeding easily.

Either remove the top hose from the thermostat housing, and then gently push the themostat open slightly with a screwdriver whilst filling, or remove the temperature sender unit. Either of these methods will allow trapped air to escape.
Fiat Panda 1000cc air lock in coolant. - jc
You will need to bleed the air out of the radiator with the screw top right side of the rad-I did break one but new ones are available-cheaply-at Fiat dealers.
Fiat Panda 1000cc air lock in coolant. - Another John H
If the thermostat is like any of the ones I've removed, or the new replacements (FIAT and QH) they have a small hole through them, presumably to prevent the problem RAILROAD describes.

IME there is a little bead retained by a small metal piece through the hole which presumably acts as a crude one-way valve.

Your mileage may vary.


Regards

ALT John H
Fiat Panda 1000cc air lock in coolant. - Pete
I was given to understand, that the " little bead " (though it may act as a rudimentery one way valve) is there to ensure that any sediment in the cooling fluid cannot accumilate and block the by-pass hole. Please correct me if I am wrong.
Rgds, Pete.
 

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