Mira 723 shower chewing up O rings - any idea why ?

[Talay]

I have a Mira 723 on high pressure where the flow piston (see attached image, diagram 13) is chewing up the small O rings on the pointy end.

Mira have replaced the complete spindle but it broke again the next day. Now they suggest it might be my water pressure.

However, their engineer stated that he was trained not to lubricate the O rings on this flow piston yet the Mira service sheet (attached) reads to me at least that these should be lubricated, to easy re-assembly.

Before we get Mira in again, would you knowledgeable chaps give me a pointer as to why this might be happening and whether these O rings really do need lubrication.

Cheers

Untitled

• Talay
• 1 Nov 2012
• 1

 

[Burnerman]

All 'O' rings in this situation need lubrication - but naturally a lubricant has to be chosen that doesn't attack the rubber, hence the corect silicone grease.
If the seals continue to fail, then its a problem with the cylinder that the piston slips into....maybe its marked, burred or has some other nasties within.
John

 

[Talay]

All 'O' rings in this situation need lubrication - but naturally a lubricant has to be chosen that doesn't attack the rubber, hence the corect silicone grease.
If the seals continue to fail, then its a problem with the cylinder that the piston slips into....maybe its marked, burred or has some other nasties within.
John

That makes complete sense to me but it is not the stance of Mira engineers in situ nor on the phone.

The burring or other nasty would presumably not be a case with a complete new assembly which Mira put in last time, to supposedly rectify the problem.

 

[Burnerman]

I'm only speaking as an engineer mate - if those seals are supposed to be mobile then they need lubrication.
I would imagine that parts such as these would be supplied and fitted as a pair, but what do I know
John

 

[Nige F]

Agree with engineer burnerman - and I`m only a P1key Plumber - but the kits used to come with a small sachet of grease

 

[neiltheplumber]

Definitely should be greased, use a silicone grease.