Hydraflush v LHM ride feel

sbraud · Post by **sbraud** » 24 Apr 2007, 10:46

Hi all,

After many years of LHM/sphere changes I thought next time I change out spheres I'd flush out with hydraflush. That time is now...

I'm up to speed with how hydraflush works and how long to use it but...

Will ride feel any different (after all air is purged after citrobics) for 2 -3 k under hydraflush or same as LHM?

Cheers
Steve

Post by **Peter.N.** » 24 Apr 2007, 11:11

I cant say I noticed any difference after a did my XM, but the fluid was nice and clean! The condition of the spheres is the primary factor in ride quality, especially the centre ones if yours is hydractive. The second is the type / condition and pressure of the tyres. Some tyres will give a softer ride as will those with most tread but the pressures have a significant effect, especially over small sharp bumps. I run my XM slightly below the reccomended pressures if I am not carrying a lot of weight and it makes a surprising difference to the ride...Not that I am recommending it of course...

rabenson · Post by **rabenson** » 24 Apr 2007, 11:46

I would have thought that it would depend on the relative viscosities of the LHM and Hydraflush. Since the suspension damping depnds on flow through a fixed orifice, if the hydraflush is noticably thinner, then the suspension will be underdamped and maybe a bit "bouncy". I suspect that the difference will be minimal.

Ron

AndersDK · Post by **AndersDK** » 24 Apr 2007, 15:32

Been running hydraflush on my (now wrecked) BX TD. Aboslutely no differences was felt in the ride comfort.
At moderate temperatures there are no significant differences on the viscosity. The viscosity of the hydraulic fluid is only an issue in very cold temperatures. At high temperatures the only issues are that the fluid should not boil, fry or evapourate.
This is because all the other mechanical functions in the hydraulic cylinders etc. sets a practical limit to any use of higher viscosity (i.e. thinner flowing) fluids.

Xaccers · Post by **Xaccers** » 24 Apr 2007, 16:02

What exactly is the composition of hydraflush and how does it work at cleaning out the system?

AndersDK · Post by **AndersDK** » 24 Apr 2007, 18:19

TBH I donno what LHM and hydraurincage fluids are composed off. I really believe you should have deep knowledge on petrochemicals to explain the differences - and compare to the more popular known engine oils - done in popular terms.

The only fact I know is that both fluids are produced from a socalled white petrolem light oil base. Its a certain destillation (or cracking) product from the oil refineries.

Note that the term "flushing" is not to be taken literally, as it is not a flushing proces like you hose away driveway dirt with a garden jet cleaner.
The term 'flushing' in this context must be interpreted as a fluid shifting process, which is a much slower working process with ongoing dilution, mixing and solution processes.

Following are the first few datasheets I found on the web for more in-depth study of the fluid specifications. You will find that there are no large differences. All products fall into the same category with much the same properties.

Total hydraurincage, safety sheets and data sheet document :
www.banlaw.com.au/media/Total%20MSDS/hydrauricage.pdf
http://www.lubadmin.com/upload/produit/ ... 4/4469.pdf

Some LHM plus, LHM+ datasheets :
http://www.morrislubricants.co.uk/image ... 20Plus.pdf
www.aral-extranet.de/sidab/data/en/2010.pdf
www.q8.dk/productservice-pdf/LHMplus.pdf
http://www.pentosin.com/flexxtrader/dat ... d7649dd407
http://www.kroon-oil.com/nl/producten/p ... 24&m=specs
www.ravenol.de/products?part=169

sbraud · Post by **sbraud** » 26 Apr 2007, 08:08

Thanks one and all

Good to know

sbraud · Post by **sbraud** » 22 Aug 2007, 20:01

OK - I don’t want to fly in the face of expertise here but...

When I originally did the hydraflush 3.5k (miles) in ago I also changed all 8 spheres to new ones. The reason for my original post was the ride. I thought new spheres all round would give me a good ride but with hydraflush in my VSX ride was not what I was expecting on new spheres. The ride was worse that before sphere/hydra change. There was a lot of pitch and roll, side to side movement on corners and back and front rise and drop on medium to hard acceleration and braking. Felt seasick for the first 1000 miles and was unhappy with overall feel.

I did full Citrorobics at least once a day since April this year to no avail and was starting to think I’d bought dodgy spheres.

This weekend I got round to changing hydraflush (from GSF) for Total LHM and…

I’m back to very very nice VSX ride now. (If you have one you’ll now what I mean) Nice and hard round corners at speed, good handling and firm absorption of roads bumps and holes.

As I say , I’m no expert here but I thought I’d pass on my observations!

Cheers
Steve

Post by **CitroJim** » 22 Aug 2007, 20:47

That is an interesting set of observations Steve,

I've just refilled with Total LHM after 1,200 miles of Hydraflush and I will offer my thoughts.

Hydraflush and LHM are a little different. If anything, Hydraflush seems thicker and more "oily" than LHM. Total LHM+ seems to have the viscosity of Vodka. It is very, very thin.

In my Activa, which was very dirty hydraulically, the ride on the old LHM was not good, even by Activa standards. The Hydraflush coincided with a filter clean and they were very badly clogged in mine. Initially the ride on Hydraflush was good but slowly it deterioriated and I also noticed the STOP light appeared to be taking a bit longer to go out toward the end.

With Total LHM+ in, the ride has improved. It is now very taut and controlled, handling-wise, whilst at the same time not overly uncomfortable on rough surfaces. Hard to describe really. Activas, despite being Hydractive, are very firm on the suspension and one could easily be forgiven for thinking they're not Hydraulic at all.

The STOP light is going out quicker too now.

Hydraflush works (I think, through observation) by holding the dirt in suspension. Certainly the Hydraflush that came out was mucky but the new LHM has not stained at all, suggesting the Hydraflush has done its job.

Maybe carrying all of those dirt particles around in suspension ultimatey affects the performance of the Hydraflush from a damping and hydraulic point of view as those dirt particles must be, by their nature, compressible.

Still, it is well worth putting up with a slightly inferior ride for a nice clean system...

sbraud · Post by **sbraud** » 24 Aug 2007, 09:26

Cheers Jim

Good to know I'm not alone on this

VSX ride sounds quite similar to Activa and I didn't mind poor ride for a few k but as opinion was ride was the same (hydraflush v LHM) my original worry was I'd got a load of duff new spheres.

Steve