Hydrolastic suspension...

[chriss13]

last week i pumped up the hydrolastic suspension on my mini after replacing all the pipes and fittings. At first, the rear of the car was sat much higher than the front but after a bit of fiddling i managed to get it to level out. But after one week of the car being sat the rear has raised much higher than the front again.. can anyone give me any ideas to what the problem could be? cheers, chris.

[guru_1071]

chris

if its not leaking fluid it will just be settleing down

you will probably have to adjust it a couple of times if its been in lots of bits as there will be air in the system and stuff like the knuckle joints need to bed in

[chriss13]

Thanks for the reply guru. Is it normal for the rear to sit higher than the front at first? and does it take long to settle down? I've just been down to the garage to work on the mini and after bouncing it around a bit the rear seems to settle down and the front rises slighly. Its going to be a few months before i can use it on the road anyway so i'll leave it stood and see what happens. Thanks again

[lewis1]

Rear will naturally tend to sit higher than the front due to the lack of weight. Give it time to settle and keep adjusting. You will get there eventually providing you have pumped them to the correct pressures etc

[guru_1071]

hydro cars do tend to sit higher at the back but its easy to fix, you simply (he says) machine a small ammount of the small metal part that locates in the displacer, where the knuckle fits in (just like sawing down the trumpet on a dry car) - that way you can run the car at the correct pressure, but set the heights your self.

it takes a little trial and error, but with time (and a hydro pump of your own) its pretty easy.

my old car was banged down to the floor, but pumped up to something stupid like 350psi, but it only took an hour so so to jack it up and stick washer in it to lift it up so i could run it soft for long journeys. i could vary the height from less than a finger between the arches and tyre - to four fingers, but keep the pressure the same

[chriss13]

The knuckle joints have been replaced so i guess that would also cause the car to sit a bit higher than it should? my dad machined about 3mm off the rods where the knuckle joints fit into last week, but it didnt seem to make any difference. I think i'll leave it sat a few weeks whilst i finish the rest of the car then take it out down some bumpy lanes and see if it settles down. then i'll probably have another fiddle with the knuckles to set it to something reasonable. Ideally a 4 finger gap between the tyre and the arch should be about right to avoid getting beached on speed bumps also, out of interest, what does a mini on hydrolastic suspension drive/handle like? as i've not had chance to drive mine yet.. cheers.

[camelotr]

I had the same problem with my Elf.

I have machined down from the rear struts, plus put some spacers under the front. This helped, but never solved the problem.

I have experienced with different hydrolastics. Finaly I have ended up using green (Cooper) displacers on front, and orange on the rear (as far as i remember).

Though still not 100% lever, but acceptable.

The hydro car handles quite well. The ride quality is a way better than the factory dry suspension. Even better with most of the soo called "comfort" coil spring kits.

Edited by camelotr on Sunday 31st October 14:42

[camelotr]

I had the same problem with my Elf.

I have machined down from the rear struts, plus put some spacers under the front. This helped, but never solved the problem.

I have experienced with different hydrolastics. Finaly I have ended up using green (Cooper) displacers on front, and orange on the rear (as far as i remember).

Though still not 100% lever, but acceptable.

The hydro car handles quite well. The ride quality is a way better than the factory dry suspension. Even better with most of the soo called "comfort" coil spring kits.

Edited by camelotr on Sunday 31st October 14:42

[chriss13]

I take it the orange displacers make the rear sit lower? we did originally think there was a problem with the front displacers on mine then someone told us it was just trapped air in the system. so after vacuuming the system them pumping it back up it was slighly better, but after a couple of days the rear had risen a couple of inches. i Just hope theres no problems with the displacers as they seem difficult to get hold of.
It will be interesting to drive a mini with hydrolastic suspension as all the minis i've been in have been on rubber cone set ups so it will be nice to drive a smooth, comfortable mini

[AndySpecD]

I've got the same on my '71 GT, although not bad enough to worry about. The GT has helper springs on the rear and I had the idea that I could probably modify these to help pull the rear down a bit.

Not sure if all hydro cars had this though?

Otherwise just put a bag of sand in the boot

[chriss13]

Ahh, mine has those too. They're suppose to balance the suspension out a bit and stop the 'buckaroo' effect i think. When you say modify.. did you chop them down?
I suppose i could drive around with a fat mate sat in the back to even it out