Possible purchase - WHY?

[shadwell]

Hi all, Despite the weather and the general anti-motoring aspects of using a car inthe Uk, I could be tempted with an MGF where the suspension is not rock hard from over-pumping; or maybe a reasonably priced early 'TF' - ideally a 1.6, but a good 1.8 as long as:
A) it has a Hardtop; and B) it has a history of belt/pump change work please?
I am in West Norfolk, but would travel a moderate distance to see a nice machine.
If you could 'pm' me with details I would much appreciate it.
Over to you,, Richard

[Reckless Rat]

MGF suspension does not go rock hard from over pumping. It goes rock hard when the spheres lose their nitrogen. It's an age related problem, but can be easily addressed by having the spheres re-gassed. There are a number of solutions available.

[shadwell]

Hi Reckless rat, I understood that by pumping more and more oil into the spheres - they call it 'regassing', but it's oil isn't it?? - which raises the ride height, but does nothing much for the actual comfort of the ride??? Or was I told wrongly? I have only heard about one place up in the Midlands which can strip and actually Re-gass spheres if you take them off and post them up. Are there more places?
I have only driven one MGF following a show locally and it really wasn't comforable at all on our potholed Norfolk roads!- - but surely it should be?? Oil can't replace the compressibility of nitrogen can it?.
Over to you, Richard

[Geoff.F]

Rimmers sell sets
Geoff.F

[shadwell]

Rimmers eh? Thanks for the info, Richard

[Reckless Rat]

Shadwell, The Hydropneumatic spheres contain nitrogen gas at high pressure. This acts as the spring. In the middle of the sphere, retaining the gas in the upper part of the sphere is a flexible membrane. Between the membrane and the membrane of the other sphere on the same side of the car is a fluid, called hydragas, which is basically antifreeze and alcohol. By applying hydraulic pressure via a pump, the fluid connection determines the height at which that side of the car sits as the front and rear are interconnected. If the membranes are damaged, or the gas escapes naturally then the spheres fill up with the hydragas fluid which effectively causes a hydraulic lock and hard suspension.

Certain firms have the technology to repair the lost gas in the spheres by welding in a valve which then enables the spring medium to be re-established. "Pumping" does nothing to repair the lost gas, all it does is raise the ride height.

MGF spheres (and all other Austin/Rover hydragas equipped cars) will normally require their spheres regassing after about 15 years, as the nitrogen escapes by a process called osmosis.

Just to reiterate, in the Rover MG hydrags the liquid is water based. The oil based oleopneumatic systems were and still are used by Citroen and other companies under licence to them. The MGF's was invented by Dr Moulton at Dunlop. It's a simpler set-up but it works.

If that doesn't explain it enough, see this link: https://www.aronline.co.uk/cars/mg-cars ... explained/

[shadwell]

Many thanks for details - very useful info. I am keen to try out a car on offer at Trophy Cars tomorrow, which will be a TF. I have not driven a TF but know that they have the more usual coil springs, but that they had pretty solid springing! So much so that they produced a 'softer' ride version later. My last car on our Norfolk roads was a Triumph Spitfire, and that didn't like the potholes at all.
Ah!!! the fun of older cars!
Richard

[Steve55]

As you say, the ride is ‘firm’! Trophy cars also sell the soft ride conversion kits but they’re a tad pricey. I bought used items which weren’t too difficult to fit once I got my hands on an impact wrench!