Ride height on the front is correct on both sides but height on rear off side is 20 mm lower than near side rear. Have Blue Hydro rear bags fitted front and rear. Comp bump stops front and rear. Standard front shocks. Suspension fully refurbished 8000 ks ago. Handling seems very good. looking at replacing the nylon cup or any other advice would be helpful before replacing the cup. Thanks, Jim.

Was the seat in the arm for the nylon cup worn? If it is, the nylon cup won't ever last and the suspension will drop.

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1986 Mayfair (998 auto), 1974 S, 1974 Van, 1972 PMG Van

Too many minis

I didn't refurb my suspension completely, just all the rubbers/nylon, but the car had sat up on stands for years before restoration and then it was re-filled. I found that it took about 12mths for it to really settle. Even when it was re-pumped several times it sagged within a couple of mths, but wasn’t leaking.

My suspicion was that the internals of the bags were probably a little perished and things were settling. The last time it was re-pumped they did a full evac and it seems to have found its happy place.

If it was a full refurb for you, could there be a bit of air trapped on that side ? The air will compress and make things sag of course.

I know left and right for me are on different pressure, one side is about 300 the other 290. So my suggestion is to try a full evac on that side to make sure any air/crap is removed and then play around with the pressure (with in reason) to adjust the ride height.

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1966 Mini Deluxe - “Gabby” 34 years under restoration and counting...
1970 MGBGT
1959 MGA

Quick question:
Is there clearance in the front suspension, between the bump stops and subframe? The car should not be constantly sitting on the bump stops.
Is this why you have matching ride-heights at the front?
When I have tried to fit competition bump stops at the front, I have had to cut off a fair bit of the rubber to get a clearance.

Hi Bill, The ride height at the front both sides is 12.5 inches axle to lip. There is clearance at the bump stops. The near side rear has good clearance about 55 mm but off side is about 30 mm. It rides well and handles very well. I do understand how this mini cooper should handle as I have competed in them for more than 30 years, but am stumped for a definite answer. A thought came to mind, I have only noticed this change after replacing the front displacer. Need to look into a problem here. Thanks, Jim.

Hydro bags - The "spacer" that inserts into the rubber and holds the knuckle joint come in different lengths and can be removed / interchanged. It is possible you have a long one on one side and short on the other.
An obvious one is to make sure you have the same length of spacers on either side.
As others have said, make sure the knuckle balls are in good condition, the nylon cups are good, and that the cup seats are not worn - these are common wear areas.
Also check all the bags are seated properly in the subframes.

Many thanks to all for your help. I never thought about the spacer. I will check out all your ideas so hopefully it will simply solve the problem. I will be doing the work late January and will report progress. Have a Merry Christmas and a great 2025. Jim.

Question about hydrolastic suspension.
Should the drive shafts be parallel to the ground when pumped up to the correct pressure as well as the correct measurement from the wheel centre to the wheel arch??

Yes

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1986 Mayfair (998 auto), 1974 S, 1974 Van, 1972 PMG Van

Too many minis

Ditto what 68+86auto said.
It's more important to have the front ride height the same, for suspension angles. The books all say that a variation in pressure of up to about 10 p.s.i. side to side is acceptable.

The problem is not yet solved. Firstly I replaced the nylon cup and knuckle joint. This became difficult as the joint would not separate from the shaft, had to partially remove the trailing arm to obtain clearance for the shaft/knuckle joint. Needed a lot of heat to separate thanks to Dr Mini. Suspension pumped up, front correct height but rear now even lower than before. It surely must be the Hydro bag. No fluid leaking from bag so must have collapsed inside. Will now be replacing the bag with another S rear bag. The saga continues.