Hydragas filling, how to?

[Hans Efde]

This morning I took my Gold convertible to a Rover specialist to pump up the hydragas units, since they were standing at 28cm. They were filled until the distance from the hub to the edge was 32cm. I drove it around the block, remeasured and it was 34cm. The mechanic let some fluid out by hand (I suppose he pinched something in the valve?) and it was 32cm again. I got back home and it was 28cm! Darn, all efforts for nothing. Question remains what is wrong? Did they something wrong or should I suspect leaks in my hydragas? I am going back on Wednesday for another try, so any advise is appreciated.
Cheers, Hans

[manifold]

Hans,

Junk the gas and fit your springs!

End of problem. Cant stand the hydrogas myself. The convertible drives a lot nicer without it.

KR

D

[Hans Efde]

Hi David,
Yes I will, but that'll be a job for the coming winter. I prefer to drive the car through the summer and then tuck it away for a few major mods.
Cheers, Hans

[wolfie]

Hi Hans, this is the problem with measuring rather than going going by the pumps pressure guage. The reason it's dropping a bit is possibly because they guy pumping it up isn't doing it properly. What he should be doing is 'bouncing' the corner he's pumping up whilst pumping. I hate the system and intend on swapping to springs

[manifold]

Also the gas unit has to be evacuated properly before re-pumping the nuclear powered fluid back in so that there arent any bubbles. Air bubbles cause all manner of issues.....and thats if the nitrogen gas hasn't done a bunk, meaning you are filling hydrolastic fluid into the top chamber of the sphere too, resulting in rock hard suspension.

One fix is to drill top of chamber and fit a valve in and fill with air. Not suited to road use due to heat generated from compressed air. It is possible to replace the nitrogen though if the middle membrane has not been perforated if you can get the nitrogen from somewhere.

Lots of hassles either way....personally I'd over pump it a few mm and live with it and do it properly this winter.

I also have this idea that it should be possible to fit those watson top hats welded onto a cut down hydrogas unit.....and this would make it really easy to fit them without welding top hat onto the subframe tower (have to remove subframe to do that). Held in as per original unit, but with the spring inside hydrogas unit instead of fluid. Would mean gutting the inside of the sphere like taking jiblets out of a chicken to make space for the spring. Chopping top off (a few mm above tower) and welding top hat on that, then chopping a bit off in bottom part too. I am pretty sure it will be best idea and something I am actively going to try out with my spare set.

Once spring in place, hi lo mechanism can be tensioned up so that it cant fall out.

Cheers,

David

[Hans Efde]

Hi David,
Sounds like a very interesting idea to me. Maybe with a bolt on strap over the tophat instead of welding it, so you can remove it anytime (to change the spring).
Yesterday I had it refilled, this time by an experienced mechanic. Properly pumping up and releasing a few times to get rid of the airbubbles and then putting it on the correct ride height while bouncing the car. It looked okay, but when we were done the 32 cm originally was increased to 34 cm. No problem because at the back my Spax dampers are at 34 cm as well. But when I got home the hydragas was even extended further to 37cm! I can no do maintenance under the car without having to jack it up! What a rubbish system. I let it sit for a week or so and then deplete a bit of the fluid.
In the mean time I'll try to see what it going on with my speedometer drive. Seems the gear in the gearbox doesn't work anymore.
Cheers, Hans

[manifold]

I agree Hans.

I thinks the hydrogas is a B*****ks system too. Thats my take on it. Rover did away with it in the end too, for various reasons both through availability and cost amongst other reasons from my understanding. Even the racers individualised them so that tells you something.

I think the top hat idea should work. Just depends on whether spring diameter is narrower than hydrogas unit at the point it passes through it. I havent toom it off to check yet. Strap over top for additional strength sounds good too. Worse case scenario is having to make another pair of top hats and the positive scenario is that you woudnt need to remove subframe/engine and rebleed brakes etc.

Is your dash the 216 rover dash. I always had issues with cable interface on back of dash, holding cable in the correct position/depth so that it would turn. Very annoying issue and was another reason for chucking that away and going the digidash route. Now I can choose to either use GPS or magnets for speed sensor. Far more precise and accurate....epecially for that extra 10 percent correction through speed cameras. Its never let me down.

Cheers,

David

[Hans Efde]

Yes it's the Rover216 dash. The cable doesn't click in place, but doesn't run loose on my car either. I can easily check it through the (unused) loudspeaker hole underneath the dash. That was my first assumption, the second one that the cable was broken. I removed it and it was fine. Yesterday I attached it to the gearbox again and pulled it through the dash so I could see/feel the end of the inner cable. While driving the car (slowly) it didn't rotate but I felt something clicking. So I assume the problem is the cable attachment to the gearbox or the pinion wheel in the gearbox itself. I'll try to get to it, but it may require removing the turbo and exhaust manifold. In the mean time I start saving for a digital dashboard (if it can display turbopressure!).
Cheers, Hans

[manifold]

Hans,

What I found with the cable was that the inner wasnt long enough......meaning it would fall out of the square hole either end. You could hear it clicking just as you say. Clicking being the square inner, jumping out of the locating hole.

One way to cure would be (was) to dismantle cable and reduce outer cable sheath a small amount. I fancied a complete change in the end and got rid of a load of issues by doing so. Especially that bit trying to connect the cable back on, whilst doing a contortionist trick!

Not sure if digidash2 lite (DD2lite) records boost. The DD2pro definately does, but for more wonga ($£).

Cheers,

David