How Often Should I Change Lhm Fluid?

[wrecker1]

Hi, I'm new here, and have owned a Xantia 1.8 petrol Estate for over 4 years now. The front suspension was really hard a year or so ago, so I had the spheres replaced (with all the rest replaced too) and it eased it a lot. But it's running slightly harder again now. I wonder if this could be that the LHM needs replacing? How often should it be replaced? And what are the symptoms of having <old> fluid in the system?

 

I should also mention that on rare occasions, I have heard a rather noisy "roaring" sound when driving, and the red STOP light has flashed on for a second or two. I tried to locate the sound under the bonnet, but couldn't locate it.

[DickieG]

LHM should be replaced every 5 years, if it is old then instead of being luminous green it will have a yellow or if very bad, black appearance (dip a white paper hankerchief into the reservior to check the colour). If LHM replacement is overdue then it damages the hydraulic system and CAN cause hydraulics to become stiff but I'd personally look towards sphere's/ride height problems.

 

Have you checked the ride height when the ride is herd as it may be that a height adjuster or its plastic connecting clip has become detached causing the car to run on the bump stops. Alternatively you may have duff sphere's, where did you get then from/what is their date of manufacture?

 

The loud roar you can hear when the red stop light illuminates may well be due to the cooling fans running on full speed. At this time of year it begs the question why? Is the coolant low/engine running hot/aircon/Bitron relay problems?

[wrecker1]

Hi Dickie,

 

I checked the LHM, and it does tend to be more yellow than green (can't decide which it is!), so I think it may be time to change it. Does a Hydrahlush make a big difference? Or can I just replace the old with the new? (Thinking about cost...)

 

The ride height seems OK, and when the car comes to a stop, the front realigns itself with no bother. I got the spheres from a local guy who just specialises in Citroen Spheres. They were recon ones. I may let him do the LHM change too.

 

The engine doesn't appear to be running hot, it never has, and there doesn't seem to be any other problems, just the hard front. Will changing LHM solve this itself, or will I need a couple of spheres too?

[DickieG]

It may well be worthwhile using Hydraflush as the old LHM is yellow which isn't the best news, get it from GSF for £15ish.

 

It sounds as if the sphere's have gone flat from what you're describing, GSF or try http://www.aepdirect.com/ who do them for £20 each.

 

Is there any difference to the firmness depending on what side of the car you push down on when stationary?

 

The fans/loud noise may well be due to a wiring fault, you'll need to take a closer look when the noise is happening in order to offer you more advice really.

[wrecker1]

Thanks Dickie. Sorry I took so long getting back.

 

I'm going to get the fluid changed, or a Hydraflush first, next weekend. I'll get the spheres changed, or recharged too. There's no difference to which side is harder, they are just not as soft as they should be.

 

I've not heard the roaring noise for a good while now, I think it was just a short term thing (I hope so!).

 

I'll let you know how I get on after next weekend.

 

Thanks for your time.

[Marty]

Just to add to Dickie's comments - go for a decent make of LHM+ such as Total as some are decidedly yellow looking from the start and dont seem to last as well as the Total stuff. For the difference in price it isnt worth scrimping a few pence.

 

Would be worth doing a full change though and washing the tank & filters out in petrol. The hardest bit of a LHM change is priming the pump afterwards. Xantias do tend to be a bit easier than BX's though possibly due to the location of the pump.

 

Bleeding the brakes, steerring and hydropneumatics is a doddle and afterwards you will be surprised at the difference in your Xants handling (and stopping).

You will also find that if you have suffered with the "pulsating pedal" problem, a LHM change and bleed through usually cures it.

[wrecker1]

Well today I had the LHM changed. I got the guy who did my spheres to do it, and he did a thorough job (washing filters in petrol etc), and he used LHM+ and it was sparkling green - thanks Marty.

 

He said that the front of the car was a little high, but he couldn't do anything about it as he doesn't have a ramp to raise the car on. He said something about a screw or nut that just needs a slight tweak to bring the front down a bit. I'll have to look into this one.

 

I don't know if I'm getting a false sense of new comfort, but the car does seem to be a lot better now. Can replacing fluid make such a difference? He said that he thought it had been changed once before in it's lifetime (It's 9 years old, I've had it nearly 5), and that It was the right time to change it.

 

Apart from the slight problem with the front height corrector, all seems well now. Thanks for your input guys. But I'm not going to cut and shut now, I'll hang around here and maybe find out a bit more about my beloved Xantia, and maybe get to know one or two of you guys.

 

Thanks again for your help and advice

 

Paul.