Gearbox breather seal

[Bobby95]

Hi all,
I own a MG ZS EV mk1 from end 2019 and still enjoy it very much. Recently I had a problem with the reduction gearbox (strange sounds) and is was replaced under warranty. When inspecting the new gearbox I removed the cap of the breather hose on the gearbox and saw that it still has plastic seal over it.

I emailed to dealer to ask if it needs to be removed (seems logical since it needs to breathe) but they told me it doesn’t need to be removed.

Since I don’t fully trust their expertise to be honest i’m curious if you guys can tell me if it indeed has to be removed or if it can stay on.

 

[Coulomb]

When inspecting the new gearbox I removed the cap of the breather hose on the gearbox and saw that it still has plastic seal over it.

Welcome to the forum.

I think that the breather is essentially a pressure relief valve, and the plastic "seal" is part of that valve.

This part was discussed in the below thread.

C

Thread 'Breather pipe'

Oct 22, 2021

On the left side of the motor (passenger side) in my ZSEV is, what appear to be a small black (plastic capped) breather pipe. Around the pipe there is a small amount of oil, which appears to have come from the pipe.

Can anyone tell me what the pipe is for, and does anyone else have any oil around it?

• Cliff Mitchell
• mg zs ev
• Replies: 44
• Forum: MG ZS EV Forum

• 

 

[Bobby95]

Welcome to the forum.

I think that the breather is essentially a pressure relief valve, and the plastic "seal" is part of that valve.

This part was discussed in the below thread.

C

Thread 'Breather pipe'

Oct 22, 2021

On the left side of the motor (passenger side) in my ZSEV is, what appear to be a small black (plastic capped) breather pipe. Around the pipe there is a small amount of oil, which appears to have come from the pipe.

Can anyone tell me what the pipe is for, and does anyone else have any oil around it?

• Cliff Mitchell
• mg zs ev
• Replies: 44
• Forum: MG ZS EV Forum

• 

Thanks for your reply @Coulomb!
I have indeed read the thread before publishing this one. Nobody seemed to have removed the cap. To me it doesn’t make sense that the seal should stay on since it, like you also said needs to relief the pressure.

 

[Coulomb]

My guess is that the "seal" usually holds the oily air in, but somehow moves such that excess air pressure is relieved when necessary. In other words, I don't think that the valve would work with that plastic part removed. It looks to me like it's designed to pop outwards under pressure, and will reset once the pressure reduces below a threshold.

 

[Bobby95]

My guess is that the "seal" usually holds the oily air in, but somehow moves such that excess air pressure is relieved when necessary. In other words, I don't think that the valve would work with that plastic part removed. It looks to me like it's designed to pop outwards under pressure, and will reset once the pressure reduces below a threshold.

Hmm that sounds logical to me indeed.. I don’t see how it could open and close again though. It is was also already full of air and under pressure after driving when pressing the white “seal”. You can feel that there is air underneath it.

 

[fred12345]

why worry, if anything goes wrong, back to the garage to fix it if they messed it up. I would not do anything myself that could invalidate warranty.