Nearside front suspension leak

[zaph2]

We have an MGF which keeps sinking on the nearside, couldn't find any leaks, bit of a mystery. So I put some UV dye in the system to see if we could locate the problem. Well it sank again, once again no sign of any leak, till I used the blacklight.

The area in front of and to inside of the front nearside tyre lit up like a Christmas tree. There is a leak somewhere in that area. Has anyone got ideas what the most likely candidate is?

[Mykel]

Pressure tube maybe?

[Charless]

Have you removed the black plastic cover under the bonnet? The tube from the nearside filler valve to the sphere may be ruptured but only leaking when the suspension moves and over pressures; guess how I know.....

[zaph2]

Have you removed the black plastic cover under the bonnet? The tube from the nearside filler valve to the sphere may be ruptured but only leaking when the suspension moves and over pressures; guess how I know.....

We have and with the dye the leak should show up.

My guess is a leaking suspension displacer.

[zaph2]

Had it apart and found the problem. The displacer is blown, it has been fitted with a Mike Satur schrader valve, fitted like a tyre valve. The fluid had blown through this valve, indicating an internal failure.

[talkingcars]

Are you sure that it isn't the valve itself that has failed?

[Rob Bell]

Are you sure that it isn't the valve itself that has failed?

I doubt it James - there's no way the fluid could get to the nitrogen egg unless the dividing membrane has failed.

With a Mike Satur re-gassing nipple, how much of the valve is inside the 'sphere? I'd be worried that the failure may be during fitment.

When the rear sphere failed on mine, it leaked outwards and downwards towards the displacer cone and knuckle joint.

It is possible that front 'spheres fail differently - particularly if you've hit a pot hole or a sleeping policeman by accident at speed...

[John SS]

Are you sure that it isn't the valve itself that has failed?

I doubt it James - there's no way the fluid could get to the nitrogen egg unless the dividing membrane has failed.

Surely even if the membrane has failed, the fluid shouldn't get past the valve?

[Rob Bell]

Nothing should be getting past the valve, unless the valve has been opened, or is faulty. To me, this sounds like a double fail

[zaph2]

My guess is the failure mode is due to how the valve was fitted. It was fitted like a tyre valve to a rim, except such a system wasn't designed for this application. The valve failed, releasing all the nitrogen, the membrane was compressed by the fluid in the system and failed. The fluid then leaked out of the failed valve.

It wasn't a massive leak, we only spotted because we filled the system with UV dye. Using a UV light it fairly easy to see where it had been leaking.