Bleeding the cooling system

mercmadjim

Senior Member
Joined
Dec 19, 2008
Messages
547
Reaction score
2
Location
Cornwall
Your Mercedes
SLK230k
I have just fitted a new water pump to my 300TE :), and in the morning I am going to put coolant in.
However I notice in the top of the thermostat housing there is a bleed screw, so I am guessing there is a procedure to follow.

Do I turn the heater control to hot ? as on some of the other cars I have done, will it self bleed?
All advice greatfully recieved.:)
 

keith100

Senior Member
Joined
Apr 6, 2008
Messages
207
Reaction score
20
Location
Toronto
Your Mercedes
w204 c300 2008 (Gone)
Hi Jim

This is what I do

1 fill rad
2 check overflow tank level is at least filled to "cold" mark
3 set heater on Max
4 start motor
5 add more coolant until it won't take any more
6 idle the motor until thermostat opens
7 watch rad until air bubbles enter the top of the rad
8 add coolant until level is stable and bubbles cease
9 tighten rad cap

Oh.... and make sure you closed any drain cocks before you add the coolant....learnt that the hard way:lol:

HTH

Keith
 

Blakey

Senior Member
Joined
Oct 11, 2007
Messages
295
Reaction score
1
Location
Brighton UK
Your Mercedes
C180 Sport (12) Blueefficiency
The odd squeeze on the bottom hose will help move any air out. :)
 

television

Always remembered RIP
Joined
Mar 14, 2005
Messages
164,073
Reaction score
367
Age
89
Location
Daventry
Your Mercedes
2002 SL500, 216 CL500, all fully loaded
Yes heater on hot, as Blakey, squeezing the bottom hose works wonders
 
OP
mercmadjim

mercmadjim

Senior Member
Joined
Dec 19, 2008
Messages
547
Reaction score
2
Location
Cornwall
Your Mercedes
SLK230k
  • Thread Starter
  • Thread starter
  • #5
Thank you very much gentlemen, I hope it's going to be smiles alround later.
 

Smudge

Senior Member
Joined
Jun 16, 2006
Messages
151
Reaction score
0
This engine can be a b**er to bleed air out off.
Your right, the top of the stat housing is a bleed screw but more importantly there are others in the head which need to be bled too. It's likely you will get an air lock in the head otherwise. This will lead to severe overheating if not done. Not sure now where the screws in the head are as my memory is not what it was.But if you have a Haynes manual it may show them in there. Or the Russian site may have exploded view of head.
 

television

Always remembered RIP
Joined
Mar 14, 2005
Messages
164,073
Reaction score
367
Age
89
Location
Daventry
Your Mercedes
2002 SL500, 216 CL500, all fully loaded
This engine can be a b**er to bleed air out off.
Your right, the top of the stat housing is a bleed screw but more importantly there are others in the head which need to be bled too. It's likely you will get an air lock in the head otherwise. This will lead to severe overheating if not done. Not sure now where the screws in the head are as my memory is not what it was.But if you have a Haynes manual it may show them in there. Or the Russian site may have exploded view of head.

When the water pump leaked on my 300TE there was never a problem filling it. there are no bleed screws to my knowledge
 

Smudge

Senior Member
Joined
Jun 16, 2006
Messages
151
Reaction score
0
Not wishing to contradict you Malcolm , but I had a real problem with getting air out of mine. Stuck a hose pipe on it in the end to blow air out.
 

television

Always remembered RIP
Joined
Mar 14, 2005
Messages
164,073
Reaction score
367
Age
89
Location
Daventry
Your Mercedes
2002 SL500, 216 CL500, all fully loaded
Not wishing to contradict you Malcolm , but I had a real problem with getting air out of mine. Stuck a hose pipe on it in the end to blow air out.

Fair comment ;):D
 
OP
mercmadjim

mercmadjim

Senior Member
Joined
Dec 19, 2008
Messages
547
Reaction score
2
Location
Cornwall
Your Mercedes
SLK230k
  • Thread Starter
  • Thread starter
  • #10
Yet again, thanks to the good people of this forum, and Television (Malcolm) with his wisdom and papers, I have saved a lot of money and fitted a water pump and bled the system on my 300TE, thank you to all people who contributed on this post and my other post http://forums.mercedesclub.org.uk/showthread.php?t=48881

Big smiles alround!!:):):):)
 

Burtie1967

Senior Member
Joined
May 1, 2013
Messages
54
Reaction score
2
Location
Stoke-on-trent
Your Mercedes
Mercedes e220 cdi classic 51 plate
Cooling system airlock

Anybody know the procedure for bleeding air out of cooling system on
Mercedes e220 cdi classic it's the 2151cc diesel on a 51- plate
 

television

Always remembered RIP
Joined
Mar 14, 2005
Messages
164,073
Reaction score
367
Age
89
Location
Daventry
Your Mercedes
2002 SL500, 216 CL500, all fully loaded
Anybody know the procedure for bleeding air out of cooling system on
Mercedes e220 cdi classic it's the 2151cc diesel on a 51- plate

There is nothing other than what is in this post, just do it the same way :D
 

mattuk

Senior Member
Joined
Oct 25, 2011
Messages
636
Reaction score
1
Location
London
Your Mercedes
c320/2001/3.2 v6
I never been bleeding on mercedes but i was doing in bmw. The warst is to get aor from matrix heater as this is the highest point in cooling system.
How high is is in mercedes?
 

television

Always remembered RIP
Joined
Mar 14, 2005
Messages
164,073
Reaction score
367
Age
89
Location
Daventry
Your Mercedes
2002 SL500, 216 CL500, all fully loaded
We never get problems in the heater matrix as the flow is reversed to normal
 

Burtie1967

Senior Member
Joined
May 1, 2013
Messages
54
Reaction score
2
Location
Stoke-on-trent
Your Mercedes
Mercedes e220 cdi classic 51 plate
Tried this but sons think I'm having any luck when I squeeze top hose it's as though I can't feel any water in it bot there was before I took inlet manifold off to modify
 

television

Always remembered RIP
Joined
Mar 14, 2005
Messages
164,073
Reaction score
367
Age
89
Location
Daventry
Your Mercedes
2002 SL500, 216 CL500, all fully loaded
Tried this but sons think I'm having any luck when I squeeze top hose it's as though I can't feel any water in it bot there was before I took inlet manifold off to modify

Please get the car up to temp thats 85c, then turn the engine off, remove the filling cap taking care not to let the water out or scold yourself, so turn it slowly to release the pressure then squeeze the bottom hose, this will send any air out, sure give the top hose a couple
 


Mercedes-Benz Servicing, repairs, engine and diagnostics
Wayne Gates - Mercedes-Benz, Unit F3, Phoenix Industrial Estate, Rosslyn Crescent, Harrow, Middlesex, HA1 2SP
Tel: 020 8863 9233
Established for 20 years all vehicles washed and vacuumed.
Top Bottom