Welcome to our resource for MG Car Information.



MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGF Technical - Help!... my F it’s not nivel!....

Hi, some help needed here...
…When I remove today my car from the garage, I notice that the right side of the car was down, the front right tyre is almost touching in the wheel interior cavity, and the right rear isn’t so low as the front wheel, but compared to the left side of the car it makes a big difference… what is now happening to my F…. HELP!…
…The thing is, my car was been trough a very expensive service (40000km) last January, with a recharge on the hydragas included, in fact the car came great and much more higher, the problem is: that I only have made 1800km since then, what was wrong with it?… (the right side came down in a week with the car parked in the garage?.. I notice that there was no liquid on the floor!)
I’m going to take my F on Monday to my dealer, that is for sure. The problem is: would they fix it only by recharging the hydragas; or they going to make a big problem out of it?…

Please, any advice would help

Bye Joao
Joao Barros Gomes

Hi Joao...

Sounds like a collapsed Hydragas unit. One of the units has failed and depressurised or one of the valves or pipes is damaged. If you have a warranty still talk to Rover and get them to pay for it. Even if you don't have cover, talk to Rover anyway, they may be willing to contribute to the cost of replacement, you never know.
Tony Smith

Just asking… How much is this “hydragas” repair costs?…
I’ve just bought an hardtop, and I’m a bit “broke” right now, if you know what I mean…

Thanks Joao

Joao Barros Gomes


sorry for this known but poor problem.
Just try at first to find out wether the rear or front unit got blown.

- lift the car at the rh front and rh rear.
(axle stand and car jack)
- remove both wheels
- locate the lower dust cover of the HG unit and press it upwards with your fingers

At the blown unit will pour or drop out some of the green stuff from a small breather hole.

May be you can see the dops already at the not lifted car. Just have a look.

The repair:
the rear and front units are different, but both cost each about 150EURO.
See site

You can try to change it mechanical yourself. Its not that difficult, only one connection and 4 bolts. Guess the front is much more easy than the rear.
After the change you can join your dealer for a full evacuation and re-pump job.

I just think about wether I could sell a second hand unit from a 57k km wreck. I kept a rear and front unit for later own use, but I have warranty for one year myself now and can try goodwill for another two years.

Anyway, at first your analysis please


Dieter Koennecke

Thanks for the info...
just one more question, is it safe to drive the car like this?… I have to drive it to the dealer (about 35km) it doesn’t hurt other mechanical stuff ?…
Dieter, tomorrow I’m going to try to see better and tell you more…. But the thing is, my car has just came from a very expensive service (included hydragas recharge), even that my F is not under warranty, the service is… right?… Doesn’t a Rover dealer service has warranty itself?… Well first thing (in my opinion), is to take the car back and ask about it… Could they wreck the hydragas unit by recharging it?…. they could be responsible for this?… In fact my F was always been assisted by this dealer!…

Thanks one more time guys

Joao Barros Gomes

no problem to go that 35 miles, but drive slow. Ech bump on the road will sound painful.
The only area I know about is the fixture cover of the front hydragas unit itself. The lower wishbone will hit against it if you go to fast and hit a bump.

Anyway, went with a broken hydragas unit for 85km at the last time and nothing happend.

>they could be responsible for this?…

;-) depends on how you can find arguments in a discussion with that dealer ;-)
Worth a try in any way and it depends on how much experiance he has with hydragas blows.

How about this 'story'.... hyphothetic only, but who cares, may be the dealer beleaves it ;-)

Average pressure of the system is about 31 Bar for a hight of 368mm. (thats true).

You know from the internet, that the HG-Unit is most reliable (LOL), but only if the right pressure is given to it. They never brake, cause Sir Moulton from Great Britain founded them.

Pressure for the hight of app 400 mm will be about 38 Bar or more. (dunno exactly)

If they pump it up to much than the lower diaphragma gets to much stressed.

Not the high pressure can result problems. A Unit withstands surely more than double of this pressure. If static load, then no problem.

But the changed 'working range' of the diaphragma can result in another term.

Inside the diaphragma is a metal mesh, like at modern tyres. (true also)

Just tell the dealer that he pumped probably up to much and this mesh got broken. After several miles thew broken mesh kills the rubber and the fluid goes off. ;-)

If he doesn't beleave this (an expert will not) than show him a print of my website related to the unit cut.
If he still doesn't beleave what you tell him, then ask him to disassemble the broken unit as I did, cause he will find the evidence you mentioned ... ROFL ;-)

May be this works. Be frienly.

Dieter Koennecke

HI again
I have just been looking to my F suspension, and I can't find any green stuff or anything similar... nothing either on the floor …
One more question… is it possible to lower the rest of the car manually?, so I can nivel both sides equal ?… and next simply ask my dealer to recharge it?…

Thanks Joao

(grrrrrrr there is a great sunshine day here)... at least my MGB still runs perfectly...but slowly
Joao Barros Gomes

If all liquid is present, it must be loss of nitrogen gas in upper sphere then ?? This space now filled with liquid ? What´s Your opinion Dieter?

To level the car there is always the trick of letting out air from the tyres at opposite side ... (Just joking !) Had this fault on our first vacation trip several years ago. Got it fixed in Hamburg for a sack of money - cheap hotels after that !!!

Regards , Carl.

Hi again,
still about my F... I leave it yesterday in my MG dealer so they could tell me what happened with my hydragas and fix it.
Today I phone them and they told me that they couldn’t find any leak from the hydragas system… so they don’t know what happen to it!…strange thing they said!... we have now recharge it, and if tomorrow it still remains OK, you could come and get it by the end of the day…
Strange thing don’t you think?… Where did go the green liquid?… It was no leak?… How…
Please some answers would help…

Thanks Joao
Joao Barros Gomes

nothing important to add to Carls messages.

Hmm, a leak of Nitrogen can IMO only appear at the upper outer pressed ring. This holds the middle section and the upper cover together and presses also the outer area of the Nitrogen diaphragma together.

Anyway, haven't got the workshop manual to hands, but there was a sequence of measuring the individual Hydragas unit nitrogen pressure, was it ?
This can't be done with a simple pump like Carls and mine. But a registered dealer should be able to check this very high pressure.

Now, may be a nitrogene diaphragma has gone. What driving behavior will be realised if one unit is filled up with fluid instead of nitrogen ?
The spring behavior of this unit will be lost !

How to measure, if a dealer can't.... ?
Dunno, but I know about workshops which special shock damper test equipment. I do not know the right english word. German is 'Stossdaempfer Test'.
I mean that equipment where only one wheel gets driven fast up and down. This wheel gets moved up and down with high frequence. The the up-down driving engine gets stopped and the damping behavior gets recorded until the up-down movement stops.

High amplitude of the wheel means that no damping behavior is there. Only the spring works.
I guess this equipment can also be used to check wether a MGF has a spring or not. Just by comparing the left 2 wheels with the resukts of the right two wheels. Right Front to Left Front should be nearly equal results and also the right rear to the left rear.

If such measurement gives no satisfying result, than at last the existing shocks can be disconnectet from the wishbones... but that sounds a bit silly, does it.

Got already 2 years ago the idea to let the spring/shock behavior of the MGF suspension measure anywhere after I found the University study works of that canadian student. I'm nearly sure that he did his studies on the hydragas units with such shock test equipment and disassembled shocks.

Long writing, but unfortunately no clear solution :(


... I see, if the upper space is (nitrogen place) is now fill with fluid, they now recharge again and the car goes to the right position... right?... but it's not supose to work like this!... or work?...
Do you get my point... what its going to happen to my F suspension?... if the upper part is fill with gas too?... the car is now at the right nivel, they clean their hands (resolve my problem) but it still works?...

bye Joao
Joao Barros Gomes

My story has just ended yesterday... I went to pick my F from my Rover dealer and they solve the problem (at least this one)…
New hydragas element – the old one had an interior failure (must broke the separator between the nitrogen an the fluid)… Dieter and Carl where right…
The car is now back on the road :)
The good thing about it, is that my MG dealer and Rover Portugal paid for it… I remember that my F is from 98 no longer on warranty…, but all service history where right, the car has made only 1800 km since last service.

Way to go Rover and MG… I am a totally satisfied client with my MG dealer (RANP – Alfragide)

Thanks to all of you for your precious help… special word for Dieter and his dedication to the F owners…

Bye João

Brg 18-12-MJ
Joao Barros Gomes

nice success for your. Looks happy to seeing that the dealers or the importer in your country is as careful to their customers as in our country.
A main part like a hydragas spring should never break after only three years.

Now the Belgium located dealers and that importer 'Hi, Luc.. :( '
needs to learn something ;-)

>Dieter and Carl where right…
Oh guy, not so much credits. If we had not answered, then other chaps would have.

Keep it running
Dieter Koennecke

This thread was discussed between 17/03/2001 and 24/03/2001

MG MGF Technical index

This thread is from the archive. The Live MG MGF Technical BBS is active now.