MGF engine subframe removal

recently bought a 1997 MGF. Read the brilliant article here on engine/subframe removal, and have no problem with it, good easy concise read, however, nowhere is there a mention of what to do about disconnecting the hydragas cannister units? They have to be discharged as I will be moving the subframe with engine and box still on it, and I intend to raise the car or jack the car up to do this but what is the procedure as regards these units ............as if I discharge them surely the suspension will just lower the car too low and make removal impossible.
Need a little guidance here please.....and if it means putting the car on blocks before discharging them where best to do this?
Cheers......Splintercat.

Hi and welcome to the forum.

When I did my subframes I got the car off its wheels on stands before releasing the pressure.

James

Thanks for that......even more axle stands to get, ha ha. when you I release the pressure from the top up points under the bonnet, I know it is left and right, but when I discharge the system does it effect both the front and rear? and as regards the to getting the car on stands you just mean the rear don't you as I intend to put the front wheels on ramps..
Thanks for the reply and sorry to ask just stupid questions just seen so many you tube videos out there on this subject that I like to be over cautious on things rather than sorry...

Click on the link below for an explanation on how the Hydagas suspension system works:
https://www.aronline.co.uk/cars/mg-cars/mgftf/technical-hydragas-explained/

It is critical to lift the front high enough to allow the car to pivot when you lift the rear as the front bumper will hit the ground otherwise and you also need room underneath to reach in and undo the suspension pipes once its been deflated.   The body drops significantly when deflated.   Here is what i did.
Undo as much as possible in the engine bay whilst the car is at normal level. you can do things like coolant pipes, brake lines, electrical cables, fuel lines, damper top nuts, exhaust etc. 
Jack up front and place some blocks under the front wheels, i think you need about minimum 6 inches but if doing the work inside then headroom becomes and issue as you will lift the rear a considerable height to remove the engine on the subframe.   chock the front wheels to stop the car rolling off the blocks. 
Lift the rear to level out the car and block under the wheels. 
i placed a Euro pallet under the subframe and shimmed it with blocks to fit the four corners of the subframe, but be aware not to block access to the large bolts holding the front of the subframe to the body work.  i marked the floor where the pallet was placed to give me a ref point for re-installation.
Deflate suspension under the bonnet using something like a plastic milkbottle to catch the fluid.  Beware, its at very high pressure so consider wearing some gasses.  undo the unions under the floor to separate the pipes. 
Finish off undoing anything left connected to the engine.     undo and remove the bolts holding the subframe to the bodywork. 
Using and engine lift or crane tied to the boot catch bodywork nside the boot lift up the rear enough for the engine to clear the bodywork.  
Using a plank(s) long enough and strong enough to span the width of car place it just ahead of the engine bay, basically under the rear of the seats and block it to take the weight of the car.  Shim it accordingly to avoid crushing any pipework.
Remove engine crane and if you have access to a pallet lift trolley pull out the engine and subrame.    From memory using a pallet under the subframe is advisable as the assembly will rotate in the engine bay of not held level.
Hope that helps.
Nigel

Update to the above after i looked at some pics i took whilst doing this job. Rather than using a Euro pallet i used the the U shaped base frame of an engine stand which has castors on it and shimmed this to the subframe in 3 places. This made it easy to pull the assembly from under the raised car.
Whilst the engine and subframe are out it is a good time to replace the brake pipes and touch up any paintwork problems as these jobs are very hard with the engine in place.

Well, thank you both, saved me a lot of head scratching, and swearing..........I will def take onboard all of your experience and the pics were a bonus thanks.....I will let you know when I start and how I get on...........................Splintercat.

You might want to get the spheres refurbished whilst doing this level of work as rear sphere removal in situ is very difficult.
Don’t park the front of the car too close to a wall when you pivot it as you will need room to access the front end to pump up the suspension when finished.
Where are you located?
Nigel