Technical How do you bleed the cooling System properly?

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Technical How do you bleed the cooling System properly?

Pras83

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Could someone please post a step by step guide.

I replaced the coolant cap with a new one but after every journey there's some coolant around the cap. (it is impossible to tighten the cap any further).

So I'm thinking maybe I have air in the system and that is causing it ?:(
 
try getting a thick plastic bag, cut a section out of it and put it over the top of the expansion tank, then screw the lip over it, i used to get coolant sprayed all over my engine bay but not anymore :)

cant help you on bleeding though, i've never done it :S
 
I'm thinking that the bag trick might be dangerous to an extent since the cap is meant to pop up under pressure hence why Pras, thinks he has a leak.

I don't have a step by step guide but if you remove the two bleeding screws (behind the drivers side headlight and behind the TB in Cinq's anyway) run the car up to temp and watch for bubbling coolant coming out of the two, once pure coolent flows through the bleed point then TIGHTEN THEM WITH YOU HANDS not tools as the screws are plastic.

Your target is to get a nice heat coming through from the blowers so get the heaters on and check, no heat means still got an airlock, if you get the kinda heat your used to then check the coolant level and whack the cap on.

There is many different methods that peeps employ but all end in the same goal.

HTH

Liam
 
Thanks Liam,

just to make sure.

Whilst bleeding do I remove the coolant tank cap or leave it on ?
 
1) Car cold

2) Remove coolant cap

3) Top up coolant level in tank with appropriate mix

4) Remove lower bleed screw, behind headlamp. Watch the coolant coming out untill it is a constant stream of water without bubbles. ( Keep one eye on the coolant level to make sue it doesn't get too low)

5) Refit bleed screw and tighten by hand only

6) Top up coolant level in tank

7) Remove upper bleed screw

8) Watch coolant as above

9) Refit upper bleed screw.

10) Check coolant level, it should be an inch or so from the top, if there is too much, release the lower bleed screw untill there is the correct quantity in the tank.

11) Refit cap, do not put a bag of any sort under the cap. As previously stated it is designed to blow off if there is too much water/pressure.

Run up to heat and make sure the fan operates correctly.

Cheers

D
 
cinqy_smurf said:
try getting a thick plastic bag, cut a section out of it and put it over the top of the expansion tank, then screw the lip over it, i used to get coolant sprayed all over my engine bay but not anymore :)

cant help you on bleeding though, i've never done it :S


Which is why your car wants to spray coolant. Bleed it properly before a hot spot pops the gasket.

Cheers

D
 
right rallycinq

I did what you said but nothing is coming out of the bleed hoses.

Makes sense though since there's no pressure on the hoses if you remove the coolant cap.

So I started the engine, let it run for about 1 min.

left the cap on.

started with the bottom one and then the top one. had a small air gap but then it was pouring out.
 
Last edited:
1) Car cold

2) Remove coolant cap

3) Top up coolant level in tank with appropriate mix well distilled water for now as bleed but week antifreeze in the cooling system better than unbleed correct mix antifreeze

4) Remove lower bleed screw, behind headlamp. Watch the coolant coming out untill it is a constant stream of water without bubbles. ( Keep one eye on the coolant level to make sue it doesn't get too low)

5) Refit bleed screw and tighten by hand only

6) Top up coolant level in tank

7) Remove upper bleed screw

8) Watch coolant as above x it seems impossible to get any coolant out of the bleed pipe, how does one proceed?
 
Well yeah, but it doesn't help the fact I, accidentally, introduced air into the cooling system this morning and now have bleed it.
 
i sorta had this problem
for a while then it went away and so did my coolant....


let me explain mine wouldnt bleed up from the top screw so i put a bag over the cap (later removed it) to build up pressure in the header tank and i squeezed the rad pipe sharply i head a sort of bubbling undid the top bleed screw and low and behold coolant was there

on my flush i used about 2 litres to top it up to full...... NO WHERE NEAR
over the next 450 miles i think i topped the header tank up 8 times each time with half a litre i now have 2 litres spare of pre mixed coolant JUST incase but i rekon there was still enough air SOMEWHERE in the system to displace 2 litres

i dunno tho... its all fine now but i never had an issue with not getting heat in through the matrix and my gauge always read as it should


the advice about the plastic screw... FAR TOO LATE....
 
I can only find a top one coming out the heater bit on my cinq sporting, so theres one behind throttle body? I will have to look there and check before I get it back out on the road after its recent water pump

No, one by the heater in the main hose and another one which is a small bore hose between the headlight and thew coolant expansion bottle
 
Thanks for your help guys. (y)

In the end I went for the Mk1 Punto 16v Haynes technique, running the engine with the header cap off at idle filling up as required for a few min then opening the top bleed screw, rather that the radiator bleed screw as said in Haynes, until clear coolant ran out. I went for a nice run down the bypass and got roasted so I'll take that as properly bleed for now... my Cinq haynes manual can't come quickly enough.
 
No, one by the heater in the main hose and another one which is a small bore hose between the headlight and thew coolant expansion bottle

In that case, mine doesnt have that either, the hose is there yes - I had to remove the top part [stupid fiat clips!!] from the water header tank, it goes from there to meet one of the bigger hoses to the rad
 
Here is the points, behind the headlight there is a hole in the wing, there should be a pipe there with a plastic screw which you can unscrew. It may have been tampered with previously and is now lying behind the bumper out of sight.

Liam
 

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This might be a Cinq/Sei difference. On mine there's a length of small bore rubber hose coming out from behind the sound proofing, the same as you see behind the headlight. The problem is the top of this hose looks to be significantly higher than the Cinq bleed screw shown in Liam's picture.
 
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