Air Lock

[S1 Roly]

Hi guys - did a search but couldn't quite find what I was looking for, so apologies if I'm asking stuff that's come up before.

After a long run, the swirl pot on my S1 always seems about half full (when it's cooled down) with very little coolant in the expansion tank - despite me having filled it up before I go. Pretty sure it isn't leaking as the cap doesn't look too bad and a lot of the hoses were replaced when the system was drained and refilled in December. So, I'm guessing an air lock could be the culprit?

The fan seems to cut in normally, and the air into the cabin is hot when the engine's at 'normal' operating temp, so I don't know if there's loads of air in the system?

I'd like to bleed it before the weekend,to make sure, but just want to check the procedure (now for the idiot questions):

Do I have to have the engine running when opening the bleed screw/filling the swirl pot?

Or do I have to fill the swirl pot, open the bleed screw listen for air, and then start the engine and run it up to temp?

And is there just the one bleed screw in the system?

An idiot's guide to bleeding the system greatly appreciated!



Cheers

Roly

[ketvrin]

I would fill the swirl tank when cold and replace pressure cap.
top up the expansion tank to about midway and replace cap (fixed seal)
Open valve to heater matrix in dash (possible location for airlock)
run engine until warm so that theres pressure
stop the engine and wait a few seconds
place a damp rag over the bleed screw and undo it gently to hopefully allow air, not scalding steam/water to escape harmlessly into the rag.

repeat a few times until you dont get anything but water and you dont need to top up the tank anymore

if theres a "special" way then I stand to be corrected but thats what I would do...

HTH

K

[Jed-S]

The pressure cap is key to the system and I've advocated replacing it as the first diagnostic step for cooling issues. Having replaced mine 2 years ago I didn't expect it to have failed so soon but couldn't see where the water was leaking. After a while I found taht there was water around the cap but couldn't spot the leak. Eventually I replaced the cap and that fixed the problem. It looks like the cap was leaking around the spring and the water was coming out above the rubber seal and therefore not making it to the overflow tank.

For the sake of 3 quid it is worth replacing the cap as the first step.

[tozerman]

ketvrin said:

I would fill the swirl tank when cold and replace pressure cap.
top up the expansion tank to about midway and replace cap (fixed seal)
Open valve to heater matrix in dash (possible location for airlock)
run engine until warm so that theres pressure
stop the engine and wait a few seconds
place a damp rag over the bleed screw and undo it gently to hopefully allow air, not scalding steam/water to escape harmlessly into the rag.

repeat a few times until you dont get anything but water and you dont need to top up the tank anymore

Thats what I do as well and it works every time for me, it never overheats or loses any coolant at all.
Cheers.....Tony..

[Stev8s]

Dont want to start the which cap goes where debate but have just fitted new rad to my V8S this week and had problems getting air out of system after filling kept blasting it out of expansion tank in the end cured it by filling expansion and leaving cap off overnight for air to escape naturally topped up next night ran it until fan cut in all cured.
P.S mine has always worked with blanking cap on swirl and pressure on expansion lets see if this starts the debate up again!!!

[Gerald-TVR]

No its simple your wrong............

[mep12345]

I'm with Stev8s, but it works both ways for me


Here we go

[S1 Roly]

Uh oh, what have I started....

Thanks for your help, fellas. I'll start with a new pressure cap and work from there.

Fingers crossed for some sun over the bank holiday.

Cheers,

Roly