23 replies to this topic

[Clip]

This is on an 1100 I’m looking at, but would be same for mini I guess. I’m used to the cones on my mini, but the hydro on this 1100 is really soft and bouncy. It’s pumped up to correct height,  but it’s like a normal car with no shock absorbers. Surely this couldn’t be right?

Edited by Clip, 06 October 2023 - 03:23 AM.

[Spider]

The Hydrolasic Suspension had damping built in to the displacers. It was done with valving inside the system.

I have to admit, it's been a very long time since I rode in an 1100, however in all the Minis that I have had and driven that have had Hydro, the valving never seemed to last long leaving them way under-damped, like you are describing. It wouldn't surprise me if the 1100 you looked at had the same issue.

The 'fix' on a Mini is to fit shocks to the front end and competition bump stops on the rear. I'm pretty sure there's no where on the trailing arms you could fit a rear shock unless you wanted to do body modifications, however, as the front and rear on each side are connected via the Hydro system, adding shocks to the front, will have a damping effect on the rear too, but therein lay the issue that finding shocks that have a 50 / 50 damping ratio is rare. The damping ratio that I'm referring to here is where the shock has the same damping rate in compression as it does in extension. Most shocks are 20 / 80 to 30 / 70. Fitting these while helping the Rear suspension will help, it will still leave it feeling under-damped.

[Clip]

Thanks Spider, much appreciated. I drove another one this afternoon and they’re night and day. This one almost seemed over damped, and was much more controlled with a firm ride. I guess the valving on the first one is shot then and that’s a deal breaker. 

[Spider]

Mmmmm,,,,, I'd be a bit suspect of that one actually. It might be OK, but I just can't see the valving lasting so well after all this time. Have a good look along the lines to see if they have fitted an external valve, even then, there maybe a resitrictor fitted in the lines,

The other way it can be cheated is the rear trailing arm pins are shimmed up, these can be set on the tight side, which won't do any of it any good. It'll wear the arms and / or thrusts in short time.

[MikeRotherham]

What was the point of the helper spring on the rear wheels of a hydrolastic mini?

 

Would that have had anything to do with dampening?

Edited by MikeRotherham, 06 October 2023 - 09:01 AM.

[Spider]

What was the point of the helper spring on the rear wheels of a hydrolastic mini?

 

Would that have had anything to do with dampening?

 

Only to raise the front, nothing to do with damping I'm afraid. The 1100 also has a spring in the back, it's a torsion set up. There was some adjustment in them. They also had a rear sway bar

[MatthewsDad]

When we talk of a valve, is that a valve in the displacer unit or somewhere along the fluid lines? If in the displacer unit is the valve repaired/ replaced when they're refurbished? Sorry, I'm new to hydro.

[Pete649]

Most shocks are 20 / 80 to 30 / 70.

How about fitting shocks with adjustable bump and rebound?

[Spider]

When we talk of a valve, is that a valve in the displacer unit or somewhere along the fluid lines? If in the displacer unit is the valve repaired/ replaced when they're refurbished? Sorry, I'm new to hydro.

 

 

The Damping Valve is internal within the Displacer.

If you go to post #10 here, Martin posted a great set of pictures of the Damper Valve.

 

 

 

Most shocks are 20 / 80 to 30 / 70.

 

How about fitting shocks with adjustable bump and rebound?

 

Yes, that could help. I don't know what range coverage is available today, but when I last tried adjustables, they didn't go that far.
 

[weef]

Before you move down the shockabsorber line I would make sure there is no air in the system, any air trapped in the units can give the symptoms you describe.

You really need the correct pump unit to evacuate the system of all fluid and to pull a vacumm before it ic refilled and set to the correct height.

[Avtovaz]

get the units serviced, the nitrogen comes out over time, so you fill it up with fluid to compensate but there is no gas left.  My rover 100 is the same. im going to send them to this guy

 

CLICK HERE

 

should make all the difference you are needing.

[Homersimpson]

get the units serviced, the nitrogen comes out over time, so you fill it up with fluid to compensate but there is no gas left.  My rover 100 is the same. im going to send them to this guy

 

CLICK HERE

 

should make all the difference you are needing.

I don't think the 1100 has gas in them, only fluid,  The 1100 and Mini were hydrolastic where the Metro/Rover 100 was hydragas.

[Avtovaz]

 

get the units serviced, the nitrogen comes out over time, so you fill it up with fluid to compensate but there is no gas left.  My rover 100 is the same. im going to send them to this guy

 

CLICK HERE

 

should make all the difference you are needing.

I don't think the 1100 has gas in them, only fluid,  The 1100 and Mini were hydrolastic where the Metro/Rover 100 was hydragas.

 

 

 

 

 

oh i stand corrected, i never knew that! i always thought they where like a hydraulic  accumulator of sorts, I should have used google! I learnt something new !! thankyou!

[Clip]

Before you move down the shockabsorber line I would make sure there is no air in the system, any air trapped in the units can give the symptoms you describe.

You really need the correct pump unit to evacuate the system of all fluid and to pull a vacumm before it ic refilled and set to the correct height.

I just spoke to the owner and they’d replaced two of the displacers, but they didn’t have the equipment to evacuate the system, so they’ve just been pumped up. I’m guessing then that it may be air in them that’s causing the soft bouncy ride?

[Clip]

Just another question, what you pay approx. for 1964 MG1100 with a fresh 1275 engine with average body (needs some paint rectification in a couple of areas, and with a good clean original interior?