Advice Required - Re-filling Cooling System
Discussion
Need some advice guys,
spent this morning refitting the radiator into my 89 400se.
I refilled the system through the swan neck, left the expansion tank empty with the pressure cap fitted. Ran the car for a couple of minutes to pump the coolant round and get rid of the worst of the air.
Switched the engine off, topped up the coolent in the swan neck and fitted the pressure cap to the swan neck.
Ran the engine again until the thermostat opened and for long enough that the cooling fan just switched on, to make sure the wiring was still working. Left the car to cool.
Just checked the coolant level:
Expansion tank level just above where it should be.
Swan neck completely empty.
Question is what to do now - do I keep filling the swan neck, running the engine until hot, switch off, let cool, check levels - if swan neck empty top up and repeat ?
Kenneth.
spent this morning refitting the radiator into my 89 400se.
I refilled the system through the swan neck, left the expansion tank empty with the pressure cap fitted. Ran the car for a couple of minutes to pump the coolant round and get rid of the worst of the air.
Switched the engine off, topped up the coolent in the swan neck and fitted the pressure cap to the swan neck.
Ran the engine again until the thermostat opened and for long enough that the cooling fan just switched on, to make sure the wiring was still working. Left the car to cool.
Just checked the coolant level:
Expansion tank level just above where it should be.
Swan neck completely empty.
Question is what to do now - do I keep filling the swan neck, running the engine until hot, switch off, let cool, check levels - if swan neck empty top up and repeat ?
Kenneth.
After a leaking otter, I managed to get another 1/2 liter into the heater matrix. Had to fill up at the bulk head where the hoses go through.
As for the missing water in the swan neck, mine does that on occasion. As the drive is on a slope, I release the main cap and the swan neck cap and when it has all siphoned to the swan neck, cap it all up. Not sure why it happens though.
As for the missing water in the swan neck, mine does that on occasion. As the drive is on a slope, I release the main cap and the swan neck cap and when it has all siphoned to the swan neck, cap it all up. Not sure why it happens though.
I always fill the system completly vis the swan and header. I then run the engine until the stat opens - usually the level will drop before closing off the header tank.
I keep filling from the swan until all the air bubbles are out that way there's minimal risk of an airlock, keeping the revs above tick over before blanking off the swan. By that time the fans should have kicked in and everything should be ok.
I keep filling from the swan until all the air bubbles are out that way there's minimal risk of an airlock, keeping the revs above tick over before blanking off the swan. By that time the fans should have kicked in and everything should be ok.
KJR - don't know what car you have as it's not on your profile !
If it's a V8 wedge - then a new rad can trap quite a bit of air and it can be tricky to get it out .. I have found top up water at swan neck - start car .. top up swan neck as necessary (leaving cap off) - turn
fan heater on full with hot air on - pump top rubber hose with hands - this aggitates water in rad - flushing out the trapped air.
If you don't get all the air out - as the water gets hotter - the air expands and pushes out the water !
Edited to add - are you signed up for the BBWF ?
Hope that helps.
>> Edited by rev-erend on Sunday 27th June 21:04
If it's a V8 wedge - then a new rad can trap quite a bit of air and it can be tricky to get it out .. I have found top up water at swan neck - start car .. top up swan neck as necessary (leaving cap off) - turn
fan heater on full with hot air on - pump top rubber hose with hands - this aggitates water in rad - flushing out the trapped air.
If you don't get all the air out - as the water gets hotter - the air expands and pushes out the water !
Edited to add - are you signed up for the BBWF ?
Hope that helps.
>> Edited by rev-erend on Sunday 27th June 21:04
Thanks for all the replys guys.
Tried the following this morning.
Checked level in expansion tank - just above normal refitted expansion tank pressure cap.
Removed swan neck pressure cap and filled up to top, squeezing hoses to remove air.
Started engine. Note that coolant is being drawn from the expansion tank into the swan neck via the small pipe which connects just below the pressure cap on the swan neck. After couple of minutes coolant is pouring from the swan neck, so decide to refit pressure cap to swan neck. Continue running engine until cooling fan starts.
Leave to cool.
Check both the swan neck and expansion tank and back to square one - both are empty.
Refill both and refit all caps.
Run engine again.
Leave to cool.
Check levels: expansion tank near normal. Swan neck not full, so fill with about 100-200ml of coolant, adding coolant in small amounts as system fully cools down.
If I were to take the car out for a run and there was still air in the system what, if any, symptoms would there be?
TIA,
KJR.
>> Edited by KJR on Monday 28th June 15:55
Tried the following this morning.
Checked level in expansion tank - just above normal refitted expansion tank pressure cap.
Removed swan neck pressure cap and filled up to top, squeezing hoses to remove air.
Started engine. Note that coolant is being drawn from the expansion tank into the swan neck via the small pipe which connects just below the pressure cap on the swan neck. After couple of minutes coolant is pouring from the swan neck, so decide to refit pressure cap to swan neck. Continue running engine until cooling fan starts.
Leave to cool.
Check both the swan neck and expansion tank and back to square one - both are empty.
Refill both and refit all caps.
Run engine again.
Leave to cool.
Check levels: expansion tank near normal. Swan neck not full, so fill with about 100-200ml of coolant, adding coolant in small amounts as system fully cools down.
If I were to take the car out for a run and there was still air in the system what, if any, symptoms would there be?
TIA,
KJR.
>> Edited by KJR on Monday 28th June 15:55
If you run as described with the swan neck cap off and expansion tank cap on - any expansion will come over the swan neck as you experienced. Sounds like you are experiencing a lot of expansion which indicates air locks.
On some (all?) V8's the swan neck vent is also the return from the plenum intake heater so you will see water flowing into the swan neck.
I have blanked the plenum feed and taken the swan vent to lower down the expansion tank (below water level). Also got the swan nexk as low as possible.
After several runs to full temp and back all seems OK Swan neck remains full and header tank remains at indicator level - no loss of water.
Warning - This is only static testing as the car is not yet on the road
David
On some (all?) V8's the swan neck vent is also the return from the plenum intake heater so you will see water flowing into the swan neck.
I have blanked the plenum feed and taken the swan vent to lower down the expansion tank (below water level). Also got the swan nexk as low as possible.
After several runs to full temp and back all seems OK Swan neck remains full and header tank remains at indicator level - no loss of water.
Warning - This is only static testing as the car is not yet on the road
David
HeyAndy said:
I always fill the system completly vis the swan and header. I then run the engine until the stat opens - usually the level will drop before closing off the header tank.
I keep filling from the swan until all the air bubbles are out that way there's minimal risk of an airlock, keeping the revs above tick over before blanking off the swan. By that time the fans should have kicked in and everything should be ok.
Yes, this is ideal however most cars will the require the cap to be refitted before the fans kick in.
KJR said:
Checked level in expansion tank - just above normal refitted expansion tank pressure cap
Better to overfill here by about a pint. Any excess will then be blown into the secondary expansion (or catchment tank) and the correct amount will (should at any rate) be sucked back as the engine colls after a run.
Thanks again for the responses guys, although it would all appear to be a little academic now - more of that later.
Took the car out for a short run, about 10 miles on a little circuit of the nearest two junctions of the local motorway. Temp rose as normal, thermostat opened and the temp dropped to normal running temp. Had the cabin heating system turned to full hot, if I turned it to full cold the engine temp gauge would start to rise so I turned it back to full hot.
Got the car home and parked in garage. After a half hour check under the car and the little leak which started all this is back.
Time for a little history - about six months ago I posted about losing coolant, a small drip from the bottom left of the radiator shroud, below the radiator top hose and otter switch.
Checked the top radiator hose and otter switch and could not see any sign of a leak. I assumed it must be the radiator - took it out and had it pressure tested no leak. Put it back in and fitted new silicon hoses. A few weeks later and the leak is back so I take the car to a local garage and get the system pressure tested in situ - still cannot find leak. Decide to leave until warmer weather before removing rad again.
Recently the leak got worse so time to start again.
Took out the rad and had it pressure tested at a different radiator specialist. They said that they could not find a leak at 3 times normal pressure. They had another go and said they found a small leak but at the opposite end of the rad from where the coolant was dripping so I was dubious that they found anything wrong. So, as it turns out I was right to be dubious.
Unless anyone has any other suggestions it looks like I will habe to bit the bullet and take the car along to local TVR specialist, Noel at V8 Sports and Classic.
Once again guys, thanks for all your input on this.
KJR.
>> Edited by KJR on Tuesday 29th June 17:42
Took the car out for a short run, about 10 miles on a little circuit of the nearest two junctions of the local motorway. Temp rose as normal, thermostat opened and the temp dropped to normal running temp. Had the cabin heating system turned to full hot, if I turned it to full cold the engine temp gauge would start to rise so I turned it back to full hot.
Got the car home and parked in garage. After a half hour check under the car and the little leak which started all this is back.
Time for a little history - about six months ago I posted about losing coolant, a small drip from the bottom left of the radiator shroud, below the radiator top hose and otter switch.
Checked the top radiator hose and otter switch and could not see any sign of a leak. I assumed it must be the radiator - took it out and had it pressure tested no leak. Put it back in and fitted new silicon hoses. A few weeks later and the leak is back so I take the car to a local garage and get the system pressure tested in situ - still cannot find leak. Decide to leave until warmer weather before removing rad again.
Recently the leak got worse so time to start again.
Took out the rad and had it pressure tested at a different radiator specialist. They said that they could not find a leak at 3 times normal pressure. They had another go and said they found a small leak but at the opposite end of the rad from where the coolant was dripping so I was dubious that they found anything wrong. So, as it turns out I was right to be dubious.
Unless anyone has any other suggestions it looks like I will habe to bit the bullet and take the car along to local TVR specialist, Noel at V8 Sports and Classic.
Once again guys, thanks for all your input on this.
KJR.
>> Edited by KJR on Tuesday 29th June 17:42
Right guys, another question this time regarding the white plastic expansion bottle with the pressure cap.
What level is the coolant supposed to be at in the expansion bottle?
When you remove the pressure cap you can see a little orange/yellow platic tower in the centre of the expansion bottle?
I have always assumed that the coolant level should be just about level with the first(lowest) platform on this tower, is this correct?
TIA,
KJR.
What level is the coolant supposed to be at in the expansion bottle?
When you remove the pressure cap you can see a little orange/yellow platic tower in the centre of the expansion bottle?
I have always assumed that the coolant level should be just about level with the first(lowest) platform on this tower, is this correct?
TIA,
KJR.
OK guys,
latest pet theory as to what is causing this leak.
In a 1989 400 SE the radiator is fitted into the car using a metal rail on each end which bolts to the wooden sides of the front of the engine bay.
Could it be the case that I am "stretching" the radiator when I am fitting it and in some way opening up part of the cooling core? Bare in mind that the radiator has been pressure tested three times and no leak has been found.
Also looking for a favour from someone with a similar car to check the following:
At each bottom corner of the radiator there is a small round peg which sits in an elongated SLOT, in the metal rail which supports the radiator and bolts it to the chassis.
In my current setup the small round pegs on the bottom of the radiator are sitting at the very outside edge of each SLOT in the metal rail. In other words to bottom of the radiator is possibly being pulled to the sides of the car.
Assuming any of the above makes sense, would someone be able to reply to let me know where, in the SLOT in the metal rail, the small round pegs are sitting on your car.
TIA,
KJR.
latest pet theory as to what is causing this leak.
In a 1989 400 SE the radiator is fitted into the car using a metal rail on each end which bolts to the wooden sides of the front of the engine bay.
Could it be the case that I am "stretching" the radiator when I am fitting it and in some way opening up part of the cooling core? Bare in mind that the radiator has been pressure tested three times and no leak has been found.
Also looking for a favour from someone with a similar car to check the following:
At each bottom corner of the radiator there is a small round peg which sits in an elongated SLOT, in the metal rail which supports the radiator and bolts it to the chassis.
In my current setup the small round pegs on the bottom of the radiator are sitting at the very outside edge of each SLOT in the metal rail. In other words to bottom of the radiator is possibly being pulled to the sides of the car.
Assuming any of the above makes sense, would someone be able to reply to let me know where, in the SLOT in the metal rail, the small round pegs are sitting on your car.
TIA,
KJR.
Not a great description but I think I know what you meam...
The radiator is really meant to 'float'..
i.e. Not be rididly mounted to a 'flexible' fibergalss body (which moves..) many put rubber mounts her to stop unwanted flexin..
but be fixed enought to stop it flyin off it's little steel posts.. it seems to work OK.
Are you saying the pressure chech shows on leaks but you still loose a small amount of water (say 1 pint per month) ... don't worry this is not unusual ..
The radiator is really meant to 'float'..
i.e. Not be rididly mounted to a 'flexible' fibergalss body (which moves..) many put rubber mounts her to stop unwanted flexin..
but be fixed enought to stop it flyin off it's little steel posts.. it seems to work OK.
Are you saying the pressure chech shows on leaks but you still loose a small amount of water (say 1 pint per month) ... don't worry this is not unusual ..
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