Technical Fully Draining Panda Coolant System

[DTanner]

I am in the process of replacing the coolant in my 2009 Panda 1.2 Dynamic Eco (no air con) and have a quick query.
I managed (after a lot of hassle) to remove the "quick" connect coupling at the bottom of the radiator and drained the coolant system (thanks to other forum responses). I opened the two bleed valves to help the system drain (one on the radiator near the coolant expansion cap and the other behind and between the airbox/battery. This was a static drain on a cold engine and I did not run the engine. Only around 3L of coolant has come out, which is around 2L less than I was expecting.

Where is the rest and is there a way to get it out?

Thanks.

 

[dozer]

Turn the heater control inside the car to hot. Then run the engine for 10 seconds or so to get any trapped water in the water pump and engine block. You'll never get all of the water out though. For the best result remove the radiator bottom hose and remove expansion tank cap.

 

[SB1500]

It's quite annoying that this non-AC design doesnt permit full draining, but my theory is if I renew what I can get out every year with fresh antifreeze it shouldnt expire and cause problems.

I think the brand new Panda's with no AC have the same system, which is rather disappointing but its one small price to pay for the super reliable FIRE engine

 

[DaveMcT]

Drain, fill with distilled water then drain again. On the second fill, add enough coolant concentrate for the whole capacity and top up with water.

The Punto Mk2 had a vent screw on the heater circuit. Isn't the Panda much the same?

These engines are great but WILL NOT TOLERATE low coolant.

 

[SB1500]

Drain, fill with distilled water then drain again. On the second fill, add enough coolant concentrate for the whole capacity and top up with water.

The Punto Mk2 had a vent screw on the heater circuit. Isn't the Panda much the same?

These engines are great but WILL NOT TOLERATE low coolant.

What happens if it's low?

And do you have a handy way to read it accurately Dave?

 

[jrkitching]

What happens if it's low?

You're quite likely to experience a head gasket failure.

Nasty.

The heater stopping working is a sure sign of dangerously low coolant; thus is true for practically any car. If it ever happens to you, stop driving immediately and (carefully as the system will be hot & pressurised) check the coolant before going any further.

And do you have a handy way to read it accurately Dave?

Use a thin strip of cardboard as a disposable dipstick. Hold between finger & thumb, insert fully into the appropriate orifice, then remove & hold it against the outside of the expansion tank with your thumb at the top to get an accurate reading. Works great on those models where the header tank is integral with the radiator (these are particularly hard to read) and is much easier than shining lights into dark places.

 

[SB1500]

You're quite likely to experience a head gasket failure.

Nasty.

The heater stopping working is a sure sign of dangerously low coolant; thus is true for practically any car. If it ever happens to you, stop driving immediately and (carefully as the system will be hot & pressurised) check the coolant before going any further.



Use a thin strip of cardboard as a disposable dipstick.

Thanks, I'll take another check of mines tonight.

Scared of overfilling it too, if you slightly overfilled it what would happen?

 

[jrkitching]

Scared of overfilling it too, if you slightly overfilled it what would happen?

Slightly, nothing.

More than slightly, most likely it would just vent out of the pressure relief valve.

Messy.

 

[DaveMcT]

What happens if it's low?

And do you have a handy way to read it accurately Dave?

As already said by @jkirching.

To properly replace the coolant you should be able to und the lowest rubber hose and drain it all out. But to clean any trapped old coolant, refill the system with clean distilled water and run the engine. Then drain it again. If its really dirty repeat the job.

Lets say the system holds 9 litres ( don't know check the manuals). If you need 33% coolant add 3 litres of concentrate and top up with distilled water. That way any trapped water wont dilute the final mixture.

If in doubt about the level an over filed system will release any excess just make sure the vent hose is fitted. @jkirching's dipstick method works well. Make absolutely sure that all trapped air is released. You might need to loosen the highest hose connector (with engine not running of course) so trapped air can escape. Run the engine, recheck the coolant level and you are good to go.

ANY gurgling from the heater is VERY bad. Stop the engine immediately and hope the head gasket gas survived.

 

[DTanner]

Great, thanks for all the feedback.

This all sounds sensible and I have filled the coolant system and all is working fine.

Thanks!

 

[DTanner]

I took the advice of all above and used the approach of DaveMcT.
I disconnected the lower radiator hose and drained, added distilled water, reconnected, ran engine briefly. Then I repeated this.
I could see the colour change from the drained coolant (losing the light rusty tinge and becoming clearer - though in fairness it looked pretty good from the start). I added the final coolant, which was partially diluted before use and further diluted by the distilled water in the system.

All worked really well and I am happy with the results.

As I originally had problems releasing the lower radiator hose I took a picture to help others (see below). I used the approach that someone else on the forum described. It involves using a wrench to depress the clip on both sides at the same time (it really does not require any force to depress the clip, it is just an awkward and stiff joint). I used the wrench to wiggle the joint (there is very little rotation of the joint as there is a mechanical keyed feature that stops rotation, but it helps). At the same time I levered the joint open with a flat metal part, like a large flat head screwdriver (the one in the image is not great but was the only one that would stay in place for the image). Wiggling with the wrench whilst applying pressure to the lever was enough to see it slowly move until it separated (be sure to have the basin in place and use gloves and goggles).
In summary the joint was stiff but in no way seized, it is just awkward. I have reopened this many times now and it is always the same (not just difficult first time).

Thanks for the help.

 

[jrkitching]

You can save yourself a lot of hassle by just syphoning out the coolant. If you use a small diameter tube, you will get out just as much coolant as you will by disconnecting the bottom hose. On models where the expansion tank is integral with the radiator, it's easy to feed a syphon tube to the lowest point in the bottom hose.

As a check, I once took off the bottom hose after syphoning out the coolant and didn't get anything more, beyond a couple of small drips.

Obviously you'll need to remove the bottom hose if the system's been neglected and needs flushing, but if it's changed regularly, there shouldn't be any contamination.

It avoids the need to disturb the somewhat fragile bottom hose connection and has another advantage - it's a lot less messy!

The idea of running distilled water through and then doing a second drain before adding a measured amount of coolant is an excellent one.

 

[Panda 2007]

Help please.

I have drained my 07 1.2 (dualogic with aircon) via the bottom hose and got about 3 litres out. I have then refilled via the expansion tank and run the car. It eventually got hot with the temperature gauge showing halfway (normal) and the fan cutting in but the air flow was still cold, (I had the heater setting on hot before I drained the system). I then drained it again. This time I just got clean water back and it seems the water had not gone through the rad and heater matrix?

How do I recommission the system properly to avoid airblocks? I've read lots of thread and thought I had done the right thing but am now worried. I can only find a bleed valve near the bulkhead.

 

[SB1500]

Help please.

I have drained my 07 1.2 (dualogic with aircon) via the bottom hose and got about 3 litres out. I have then refilled via the expansion tank and run the car. It eventually got hot with the temperature gauge showing halfway (normal) and the fan cutting in but the air flow was still cold, (I had the heater setting on hot before I drained the system). I then drained it again. This time I just got clean water back and it seems the water had not gone through the rad and heater matrix?

How do I recommission the system properly to avoid airblocks? I've read lots of thread and thought I had done the right thing but am now worried. I can only find a bleed valve near the bulkhead.

First of all, don't panic.

You need to bleed the system after any changes to the cooling system.

There's a little valve / screw which is the bleeder screw. When you look under the bonnet, it is on your RIGHT towards the cabin. DO NOT undo the left one as this is some sort of fuel line.. we learnt that the hard way!

With the car started, and the heater set to HOT top up the coolant system to the right level (between MIN / MAX) and open the bleed screw so that you feel air coming out until this stops. You'll see the coolant drop as this happens.

Keep topping it up, then bleeding / tightening the bleed screw / releasing it to let air out.

It's a long process, and repetitive until hot air starts coming out of the vents. And by hot I mean as hot as you're used to, not just lukewarm.

Also, over the next few weeks release the bleed screw to let out excess air, it takes time to get every last bit out. And make sure your coolant level is staying up!

Hope this help, correct me if I'm wrong / missed steps anyone!

 

[varesecrazy]

First of all, don't panic.

You need to bleed the system after any changes to the cooling system.

There's a little valve / screw which is the bleeder screw. When you look under the bonnet, it is on your RIGHT towards the cabin. DO NOT undo the left one as this is some sort of fuel line.. we learnt that the hard way!

With the car started, and the heater set to HOT top up the coolant system to the right level (between MIN / MAX) and open the bleed screw so that you feel air coming out until this stops. You'll see the coolant drop as this happens.

Keep topping it up, then bleeding / tightening the bleed screw / releasing it to let air out.

It's a long process, and repetitive until hot air starts coming out of the vents. And by hot I mean as hot as you're used to, not just lukewarm.

Also, over the next few weeks release the bleed screw to let out excess air, it takes time to get every last bit out. And make sure your coolant level is staying up!

Hope this help, correct me if I'm wrong / missed steps anyone!

Minor point ;
ENGINE OFF = I tend to undo the bleed screws,
and fill radiator tank with water until it dribbles out of them,

close the bleed screws,
then fill the rad tank to within 1 inch / 30mm of the top neck,
start engine - leave rad cap OFF,
it'll "burp itself" but with so much fluid in the system it can't draw in additional air,

let the engine idle until the cabin air is HOT,
then blip throttle / raise revs a few times, may just shift a couple of bits of trapped air
let COOL ( engine OFF) , check level on expansion tank -for reference..
and then dump water , and do the same basic procedure with the new coolant mix,

Charlie - 2004 1.1 Active

 

[Panda 2007]

Thanks for the prompt and helpful replies guys. Have to wait until Sunday to have another go but feel reassured now. Cheers.

 

[DaveMcT]

The bleed screws are plastic so be careful. If you are unfortunate enough to shear on off you can fit an M6 stainless screw and washer.