Water leak 2.5KV6 - Page 2

trikey · 14th October 2018, 16:18

[QUOTE=bluemalbert;2677358]

Quote:

Originally Posted by marinabrian

Black O rings are original spec, pink O rings have changed colour due to being in contact with a chemical that is red in colour.

The O rings have failed due to compression set

Brian

Brian - possibly a slight misunderstanding from my shoddy description, but the new O rings on the new pipe in a sealed bag from an MG dealer are a pinky colour and exactly the same colour as the O rings which came off the leaking bits at 5k.

So they hadn't changed colour, just flattened off!

Pink O rings! I have never seen a new O ring that was pink?

Yorkshire GOC · 14th October 2018, 16:23

[QUOTE=trikey;2677364]

Quote:

Originally Posted by bluemalbert

Pink O rings! I have never seen a new O ring that was pink?

That will confuse things

marinabrian · 14th October 2018, 20:07

Quote:

Originally Posted by bluemalbert

Brian - possibly a slight misunderstanding from my shoddy description, but the new O rings on the new pipe in a sealed bag from an MG dealer are a pinky colour and exactly the same colour as the O rings which came off the leaking bits at 5k.

So they hadn't changed colour, just flattened off!

They're still suffering from compression set though Malcolm, that is the name of the failure mode, the symptom of which the O ring swells due to chemical incompatibility between the o ring and the media it is sealing against.

The appearance is that of the outer circumference of the o ring changing in profile from curved to flat, as it has swollen to fill the void in the groove, this is not to be confused with failure due to abrasion, which presents completely differently

The O rings should be black in colour, part number is CDU3858, and here we have yet another example of substandard components from the far east being sold, being unfit for purpose, irrespective of what packaging they arrive in.

Brian

bluemalbert · 1st November 2018, 09:07

[QUOTE=marinabrian;2677506]They're still suffering from compression set though Malcolm, that is the name of the failure mode, the symptom of which the O ring swells due to chemical incompatibility between the o ring and the media it is sealing against.

The appearance is that of the outer circumference of the o ring changing in profile from curved to flat, as it has swollen to fill the void in the groove, this is not to be confused with failure due to abrasion, which presents completely differently

The O rings should be black in colour, part number is CDU3858, and here we have yet another example of substandard components from the far east being sold, being unfit for purpose, irrespective of what packaging they arrive in.

Brian

Thanks Brian - I tend to go with your observation of poss Far East O rings which now seems more possible as after 850 miles (trouble free) the V is flooded!

I cant see exactly which joint is leaking but have ordered rings from Rimmers and the guy promised me they are black!! They should arrive today, so watch this space.

1st November 2018, 09:07	#14
bluemalbert Avid contributor MG ZT 190 Join Date: Apr 2016 Location: Heathrow Posts: 166 Thanks: 109 Thanked 24 Times in 14 Posts	Leaking AGAIN! [QUOTE=marinabrian;2677506]They're still suffering from compression set though Malcolm, that is the name of the failure mode, the symptom of which the O ring swells due to chemical incompatibility between the o ring and the media it is sealing against. The appearance is that of the outer circumference of the o ring changing in profile from curved to flat, as it has swollen to fill the void in the groove, this is not to be confused with failure due to abrasion, which presents completely differently The O rings should be black in colour, part number is CDU3858, and here we have yet another example of substandard components from the far east being sold, being unfit for purpose, irrespective of what packaging they arrive in. Brian Thanks Brian - I tend to go with your observation of poss Far East O rings which now seems more possible as after 850 miles (trouble free) the V is flooded! I cant see exactly which joint is leaking but have ordered rings from Rimmers and the guy promised me they are black!! They should arrive today, so watch this space.