Coolant Problem
Discussion
Went out for a bit of a spirited drive just now, got home, put it back into the garage and after putting the roof panels back on found this.
It's been behaving fine up until now, I've been conscious of keeping an eye on the temp gauge and all appeared well.
The header tank is now full to the brim, looks like the pressure cap on the swirl pot has leaked spraying coolant when the pressure valve has opened. Letting it cool down a bit before I check level in the swirl pot. You can see where it's dripped down the side of the swirl pot here.
The pressure cap is rated at 15lbs, is that right? I'm sure I purchased the same as was on originally. Can anyone recommend a replacement that's a tighter fit? I've already tried bending the tabs up a bit for a tighter seal (if that makes sense).
Am I correct in believing the only bleed point is on the radiator?
Any ideas what could have happened?
Heaters working fine.
Thanks
Lawrie
It's been behaving fine up until now, I've been conscious of keeping an eye on the temp gauge and all appeared well.
The header tank is now full to the brim, looks like the pressure cap on the swirl pot has leaked spraying coolant when the pressure valve has opened. Letting it cool down a bit before I check level in the swirl pot. You can see where it's dripped down the side of the swirl pot here.
The pressure cap is rated at 15lbs, is that right? I'm sure I purchased the same as was on originally. Can anyone recommend a replacement that's a tighter fit? I've already tried bending the tabs up a bit for a tighter seal (if that makes sense).
Am I correct in believing the only bleed point is on the radiator?
Any ideas what could have happened?
Heaters working fine.
Thanks
Lawrie
LawrieS said:
...Should the fan come on if I short the connectors to the otter switch with ignition on?
Yes.I have the same twin stainless set up as you and my cap is 15psi. However (run & hide now
) I have the pressure cap on the expansion tank.Do you have the correct pressure cap which allows coolant to flow back into the swirl tank as it cools?
Well in that case my fans not working, I can hear a relay click but no fan. It worked previously and is definitely plugged in.
The cap is made by fah-ler, not sure about the return thing.
I'll sort the fan and swap them round
see what happens.
Guess it got a bit warm whilst sat on the drive running whilst I opened the garage doors.
The cap is made by fah-ler, not sure about the return thing.
I'll sort the fan and swap them round
see what happens.Guess it got a bit warm whilst sat on the drive running whilst I opened the garage doors.
Edited by LawrieS on Sunday 17th May 18:46
LawrieS said:
The cap is made by fah-ler.
Bought two of their caps, used the spare seal (not needed on the exp. tank) to double up this seal on the swirl pot to get things to seal ok.
Do you still have the original orange fan in front of the rad? It could be kaput but it might just be the electrical connections down near the front cross member, somewhere near the horns?
Is that a second pressure cap on your expansion tank? If so that might be your problem, especially if is a higher psi than the one on the swirl tank. If you're running the pressure cap on the swirl tank then you just need a simple cap for the expansion tank, otherwise it is under pressure when the swirl tank tries to vent off surplus as the system heats up and so the system blows off at the weakest point. At least you know the rest of your system is OK 
I had a similar issue. The cap i purchased was 15IB however it did not have the top seal but a metal disk and it is short reach. I purchased a long reach cap with two seals, one to seal the top of the swirlpot and one that sealed the ledge inside the swirlpot neck and all was fine.
FYI Car builder solutions sell the correct cap.
With the short reach cap, as soon as the pressure started to rise, the water was being pushed straight into the expansion tank. Squeezing the top hose made the water level in the expansion tank rise, when the cap should have prevented it.
FYI Car builder solutions sell the correct cap.
With the short reach cap, as soon as the pressure started to rise, the water was being pushed straight into the expansion tank. Squeezing the top hose made the water level in the expansion tank rise, when the cap should have prevented it.
So just how much longer does the "plunger" have to be relative to the depth of the neck? I have a new Q&H cap here with a rubber top and bottom seal with a "reach" of 20mm (excluding the rubber top seal) compared to the depth of the neck at 19mm. This goes on tighter than the old cap which has a steel top seal and a "reach" of 21mm. As I've got the pressure cap on the expansion tank I don't think it matters whether on not I have a steel or rubber top seal because if the pressure lifts the lower seal it vents out the over flow anyway; doesn't it? I've got a 1 litre expansion tank which I half fill giving me 500cc of venting space.
If the spring on my old cap has become "lazy" and is releasing at too low a pressure would this allow the cooling system to run at a higher temperature and so switch the fan on sooner?
If the spring on my old cap has become "lazy" and is releasing at too low a pressure would this allow the cooling system to run at a higher temperature and so switch the fan on sooner?
HvdWeerden said:
...I was once told that you should never fill the header to the brim. .... When coolant warms up there is always room for expansion...
I'll second that. You have to leave room for the expanded coolant otherwise it will vent off out the over-flow. You have a 1 litre tank as well so you only need to half fill it.1.never fill the swirl pot right up, there must be air space for expansion or it will definitely blow.
2. check the Fahler stainless cap carefully, I bought a pair as well, they look nice but are not built to as a high a standard as the originals. I had to bend the tabs on one to get it to hold straight, and one also had a small defect in the 'rubber' seal. Didnt look much but it caused an immediate leak. They had to change it for me.
3. I would be a little concerned about the colour of that water, if I am seeing it right. Strongly suggest back flushing the system to get rid of the brown then refilling using a good quality antifreeze which will include a rust inhibitor
2. check the Fahler stainless cap carefully, I bought a pair as well, they look nice but are not built to as a high a standard as the originals. I had to bend the tabs on one to get it to hold straight, and one also had a small defect in the 'rubber' seal. Didnt look much but it caused an immediate leak. They had to change it for me.
3. I would be a little concerned about the colour of that water, if I am seeing it right. Strongly suggest back flushing the system to get rid of the brown then refilling using a good quality antifreeze which will include a rust inhibitor
greymrj said:
1.never fill the swirl pot right up, there must be air space for expansion or it will definitely blow.
If the system is working properly the swirlpot will be full as any air is pushed out into the expansion tank when hot and then coolant is drawn back the swirlpot as it cools. This is how it is designed to work to ensure that there is no air in the engine cooling system.Hi, so after reading the Steve Heath "bible" it seems to suggest that the pressure cap is on the tank with the top hose entering it , and the normal unpressurised cap is on the header tank ?. Also do not use OAT antifreeze if you have any silicon hoses , as it will ultimately destroy them as it contains sodium-2 ethyl hexanoate (2-EHA). Good old bluecol will do !, or look for an OAT coolant without 2-EHA
tango123 said:
Hi, so after reading the Steve Heath "bible" it seems to suggest that the pressure cap is on the tank with the top hose entering it , and the normal unpressurised cap is on the header tank ?. Also do not use OAT antifreeze if you have any silicon hoses , as it will ultimately destroy them as it contains sodium-2 ethyl hexanoate (2-EHA). Good old bluecol will do !, or look for an OAT coolant without 2-EHA
OAT type antifreeze is not recommended for older systems containing copper, brass and solder. There is a detailed article on this somewhere but I can't find it at the moment.v8s4me said:
So just how much longer does the "plunger" have to be relative to the depth of the neck? I have a new Q&H cap here with a rubber top and bottom seal with a "reach" of 20mm (excluding the rubber top seal) compared to the depth of the neck at 19mm. This goes on tighter than the old cap which has a steel top seal and a "reach" of 21mm. As I've got the pressure cap on the expansion tank I don't think it matters whether on not I have a steel or rubber top seal because if the pressure lifts the lower seal it vents out the over flow anyway; doesn't it? I've got a 1 litre expansion tank which I half fill giving me 500cc of venting space.
If the spring on my old cap has become "lazy" and is releasing at too low a pressure would this allow the cooling system to run at a higher temperature and so switch the fan on sooner?
JoeIf the spring on my old cap has become "lazy" and is releasing at too low a pressure would this allow the cooling system to run at a higher temperature and so switch the fan on sooner?
22mm and 26mm for short and long respectively. Measured from face of the upper seal to the face of the lower seal.
I guess if your spring has gone lazy, it would allow the water to boil sooner. I understand the pressure raises the boiling point of the water. But your fans are switched on by the otter switch which will still work at the same water temperature regardless if the boiling point. The cap raises the gap between the fans coming on and the water boiling. Of course this could be complete bo!!ox.
Edited by Oldred_V8S on Monday 18th May 13:57
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