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#1 Another stoopid question

Posted: Fri Apr 26, 2019 5:55 pm
by malcolm
The radiator expansion tank on my series 2 has two pipes; one runs to the radiator, the other is an overflow pipe. At the moment, the pipe to the radiator is on the higher expansion tank fitting. The overflow pipe is on the lower one. Surely this is wrong? Otherwise, when you top up the radiator via the expansion tank, the level hits the overflow and discharges before water goes to the radiator?
Am I missing something? Is my logic wrong?

#2 Re: Another stoopid question

Posted: Fri Apr 26, 2019 6:03 pm
by tim wood
Yes, these are the wrong way round

#3 Re: Another stoopid question

Posted: Fri Apr 26, 2019 6:11 pm
by mgcjag
Hi Malcom....you do realise that you dont fill the radiator via the expansion tank.........you fill the rad to bottom of neck....then fit the plain cap....then half fill the expansion tank and fit the pressure cap....Steve

#4 Re: Another stoopid question

Posted: Fri Apr 26, 2019 7:01 pm
by malcolm
Ah, ok, thanks both. But Steve, what about the way they are connected?

#5 Re: Another stoopid question

Posted: Fri Apr 26, 2019 7:25 pm
by PeterCrespin
malcolm wrote:
Fri Apr 26, 2019 7:01 pm
But Steve, what about the way they are connected?
You suspected it was wrong.
You’ve had it confirmed.
You’ve had an extra error spelled out.
Now you want an additional opinion?

#6 Re: Another stoopid question

Posted: Fri Apr 26, 2019 7:30 pm
by 288gto
Hi Malcolm,

Radiator to the lower of the two pipes on the expansion tank. The overflow is on the neck of the expansion tank and is only open when the pressure relief valve on the cap is activated. If I recall correctly it is 7lbs. Make sure you have the correct caps on the rad and the expansion tank , they are different. Pressure cap goes on the expansion tank and the plain one on the radiator.

Hopefully that makes sense.

Simon

#7 Re: Another stoopid question

Posted: Fri Apr 26, 2019 7:44 pm
by JJC
Malcolm: Listen to Tim, forget the rest. Actually, if you think about how the system works, you would have figured it out.

Have fun.

JJ

#8 Re: Another stoopid question

Posted: Fri Apr 26, 2019 7:51 pm
by mgcjag
Hi JJ.....if you think Simon and myself have given incorrect information then please explain.......rather than just say ignore what we have said.....Steve

#9 Re: Another stoopid question

Posted: Sat Apr 27, 2019 8:54 am
by PeterCrespin
Malcolm did figure it out. He came here for confirmation.

It was just his filling technique that was a little hokey, but even that would sort itself out after one heat cycle if the plumbing was corrected

#10 Re: Another stoopid question

Posted: Sat Apr 27, 2019 8:58 am
by malcolm
Thanks for all that detail, which is what I needed. Caps checked and ok with pressure cap on expansion tank. Hoses now swopped round. Topping up via rad now.

#11 Re: Another stoopid question

Posted: Sat Apr 27, 2019 9:14 am
by christopher storey
JJC wrote:
Fri Apr 26, 2019 7:44 pm
Malcolm: Listen to Tim, forget the rest. Actually, if you think about how the system works, you would have figured it out.

Have fun.

JJ
Do not just listen to Tim, although what he said was perfectly correct. The other advice given about the radiator caps was equally important and also correct, and furthermore the transposition of the caps often gives rise to all kinds of troubles. JJC, who is a V12 man, may be unaware of this

#12 Re: Another stoopid question

Posted: Sat Apr 27, 2019 1:36 pm
by malcolm
Thanks Christopher, all good now!