Hydrolastic suspension adjustment questions

[gvdbosch]

I bought a suspension pump from Minispares to adjust the ride height of my Mini Cooper S but encountered two problems when using it as a newbie. The instructions for use of the Alba Diagnostics pump clearly state to just use bare hands to tighten the connector to the car but when doing this I wasn't able to pump any fluid into the system without a major leak at the connector. Only after using an 18 wrench the connector was tight enough to pump fluid without leaks. Despite the warning in the instructions, this was the only way to get things working properly, which puzzled me. I managed to get the car on the right height but after a few days I noticed that the displacers were leaking a little bit (about 1 drop a day). Is this normal right after a fill up of the hydrolastic system or does this imply a leakage at the valves in the displacers ? The hydrolastic fluid I drained from the car was brown instead of green, so it had clearly been a long time since the fluid had been changed by the previous owner (hence the low ride height....) and I have not spotted any leaks before my work on the hydrolastic system. Some advice from more experienced Mini hydrolastic mechanics would be most welcome !

[Spider]

The System doesn't normally leak and only needs 'topping up' or adjusting if there's been work done that required depressurization of the system.

It's likely your leaks are from where the hoses are connected on to the displacers, if it's in the bag itself, they let go in a big way and with next to no warning. These are a crimped hose connection. There is a firm who reconditions them, but they are limited on how far they can go with them. It might be an opportunity if you were to remove the displacers to fit new valve assemblies (the fillers) too.

[111Robin]

Regarding connecting the pump to the valve, maybe you have misinterpreted the instructions. I don't know this specific pump but the connection to the valve must be the same as all pumps. You have to tighten the hex union nut to the valve with a spanner, not stupid tight just nip it up or it will leak. To unseat the valve the centre part only needs to be finger tight as all you are doing is pushing the valve stem off its seat.

[Peter Laidler]

Ah, gvdbosch. A question for you first. Where are you calling from?

I have made a detailed study of the hydrolastic systems, sadly fitted to our cars. As a result, there are many articles on the details of what, why and how within this very forum. And better still, how to give your suspension a good clear-out and get things right......... ALL without the benefit of a hydrolastic cabinet. But you'll need to find it and read it first.

We've all been there and as I say every time, DON'T LET HYDROLASTIC FRIGHTEN YOU.

But, back to the questions you as. It seems as though your hydro system sufferes from what most others suffer from. That is that the hydrolastic cabinet drains down your system into a tank...... including the shite and rusty sewage. It recirculates this back INTO the system when you decide to pump it up.

What you need to do is to FULLY drain down both sides of your system, flush it out and fill with clean, new hydro fluid. Then use the machine to pressurise it. There's a bit more to it than that of course but I have only got an hour to go through it quickly.

As has been said, if your system is going down, it is because there is a leak, albeit a very small one. It's not the valves INSIDE the displacers. They have already totally rusted out by now. The leak is from the exterior of the system. At a joint, a pipe or one of the hydrolastic bags. As Spider says, (we have discussed this between us MANY times, believe me.....) the external valves at the rear do fail and are a simple replacemenr too

If I was you....... I would start again by taking the system apart, flush it out and............... I will PM you

[gvdbosch]

Many thanks already for all your suggestions ! I am calling from Belgium, but have a weak spot for British cars. The seller of my Mini said he had serviced the hydrolastic system before delivery but I doubt that sincerely when I saw the dark brown fluid coming out of the left side hydrolastic system....The renewed green fluid is now slowly dripping from the caps on the displacers, the ride heigh however has changed very little until now. I would like to keep the hydrolastic system though because it is truly characteristic for this classic Mini.

Glenn

[Peter Laidler]

When you say '.....caps on the displacers.....' wehat do you mean? There are no caps on the displacers. The only caps are the plastic caps on the valves.

Read my PM to you regarding these valves, new cores and the use of small dental scrubbers

This brown liquid is the death sentence for the internal parts of your displacers

[gazza82]

The seller of my Mini said he had serviced the hydrolastic system before delivery but I doubt that sincerely when I saw the dark brown fluid coming out of the left side hydrolastic system....

Sounds like the same person running an auction house in the UK who is selling a vehicle it describes as having a "thorough restoration" ... but hasn't spotted, or wants to mention, the vast amount of filler that has been applied to hide the wing seams (normally has plastic piping between the panels on this particular vehicle) and the rear wings which are a completely different shape to the originals (and a seam has been covered there too!). Who knows what else is hidden behind the Isopon!!

Anyone looking at that car needs to take a magnet with them ... but be prepared to pick it up off the floor a lot!

Caveat Emptor ... Buyer Beware!

[gvdbosch]

Sorry, I was indeed referring to the plastic dust caps on the valves !

[Terence]

You might need to replace the fill valves, the seals will fail over time.
http://www.minispares.com/product/Classic/13H1705.aspx

[Peter Laidler]

Fair point from Terry. But make sure before you go the the bother and expense of fitting new valve asssemblies, that you scrub out the internal s of the old valves and fit new cores first. Interdental brushes, cheap by the packet from Tesco in several hardnesses....., but they're all pretty soft!.

Terry also raises another good point. If you can, take a look at the size of the hole at the BACK end of the hydro valves (or tyre valves.....). This is the reason why you will NEVER, not in a zillion years, fully flush out your grotty hydrolastic system. The lumps of crud, old rusty bits and shite simply won't pass through the hole in the valve. And don't even try to do it with the valve core in place.

Hydrolastic......, my pet hate. A frill, if not a total fraud