27 replies to this topic

[Lukie-J]

Is it the same as a mini? hi-los? cut trumpets?

Thanks in advance.

[Ethel]

Just bleed off some suspension fluid. Same caution is required not to unload it at full rebound so it drops to bits.

Is it the same as a mini? hi-los? cut trumpets?

Thanks in advance.

[Cooperman]

It has a fluid suspension system similar to a hydrolastic Mini, so presumably you just let some fluid out of the suspension.

[crazycoleman118]

as ever#yone above has stated just let fluid out... you can get them slaaaaammmeeeedddd... not soo driveable but it looks good

[mini13]

you can let some fluid out, but this effectivly leaves you running a softer spring,

the proper way to do it is to de presurise the system and cut the struts (trumpets)

[bmcecosse]

I agree - the fluid pressure should NOT be reduced.

[Lukie-J]

How would I go about letting the fluid out?? And roughly how much??

[MRA]

This can lead to some really odd handling traits not a good idea to lower a metro without adjusting the length of the bottom arms, or fitting the TICKFORD bottom arms which will cure this

[Ethel]

You've got a strut that pushes on some fluid to compress a bag of gas. I can't see how it makes much difference if you alter the strut or the fluid, they do exactly the same job, you barely have to worry about running out of fluid on a Metro either, with no communication pipe to talk of. Trying to increase the pressure and will just lift the car.

[mk1leg]

Chain saw..............

[POWER5LAVE]

just a word of warning when lowering a metro. DONT go to low. as a family me and my moms fella have owned a few and when you can't get a jack under them its too LOW. lol is funny when you get stuck on a speed bump and people just stand and stare while you push the car off lol.

[MRA]

If we are talking about reducing the amount of fluid..... then it will raise or lower the car dependant on the amount added or removed, it acts on the gas bag directly effecting the spring rate as it is a fluid and almost incompressible, the "spring" is in the gas filled bag above the liquid, reducing that "volume" by increasing the fluid pressure raises the spring rate. In CCC (Car & Car Conversions) magazine some years prior to Mini World being published they ran an article on lowering the Metro, they braised on another schrader valve to allow for changes in the operating pressure, it needs to at about 250 to 300psi

If you are going to lower it then reduce the mechanical length of the strut, not the fluid amount, and whem you re-assemble it all you will need to get the pressure right at approx 275psi

[Ethel]

But the pressure is a product of the weight of the car. You can't increase it (without altering the area the pressure is pushing on) beyond what is needed to support the car unless it's at the full extent of its travel. There might be a little difference in lever rates as it jacks up on to its tippy toes, but you'd get that by chopping down the struts too.

[MRA]

after driving a metro that has been lowered by fluid removal it is a completely different experience..............

The displacement is due to the body mass and gravity acting down on the suspension, but the hydrolastic units are pre sealed pressurised units, if you remove one from the car it will still be under about 275psi.......

Think of it in terms of the shear value of the rubber doughnut as used in dry Mini's

[MRA]

Also don't forget that it's the fluid that changes the shape of the diaphragm, reducing the fluid has an adverse effect on this shape.