Hydraulics, not able to get normal ride height

[eric]

Hi folks,i'm new on here and am having problems with a 2.1vsx estate i bought off ebay last week("you fool"i hear you say).The car is a 95 N reg,48.000mls,number on the inside of the passenger door is 6700.
The problem which was'nt apparent when i looked at the car is that it won't pump up to normal height.If i raise it upto max it goes up,if i lower it to min it only goes down on the back,staying up at the front.The intermediate setting just appears to raise it to max.I have cleaned the filters in petrol.Any ideas on rectification would be greatly appreciated.Thanks.Eric

[noz]

Hi Eric,

Welcome to club-xm. I hope you find it friendly and useful here.

The devices which control the height at which the front and rear of the car reside are called height correctors. There are two of them, one for the front and one for the rear. They are very simply, little slide valves. The valve slider position is dictated by a lever which in turn is connected, via a torsion spring, to the anti-roll bar in each case. As the anti-roll bar rotates (as the height of the car changes) then the slide in the height corrector is moved accordingly. If the height is too low then the slide valve in the HC allows more fluid under pressure from the pump to reach the hydraulic circuit connected to the wheels. If the height is too high then the slide valve is pulled the other way and allows some of the stored pressure in the wheel hydraulic circuits to bleed back to the reservoir. At the optimum height the slide valve in the HC is closed in both directions and the fluid in the circuit stays put.

The height corrector themselves are very reliable but the external levers and torsion springs are prone to rust particularly around the pivots. Having said that, the problem is easily resolved. With the car up on ramps (do NOT try this with the car on the flat. Tampering with the height corrector will make the car body drop very quickly crushing you if you are beneath the car) identify the two height correctors. They are barrell shaped approx 50mm diameter, aluminium bodies, two black rubber cap ends, two steel pipe connections and one plastic pipe connection with a black rubber connector. You'll find a plastic dumbell connecting rod with a ball and socket at either end. The dumbell then connects to the lever, torsion spring and finally to a clamp on the anti-roll bar.

Prise the dumbells off their respective B&S's. Now grab each lever and torsion spring and work them back and forth liberally greasing the pivot point. Continue to work them back and forth until you are sure they are free. If you push and pull on the dumbells connected to the HC's you can get the body of the car to rise and fall. Hold the dumbells at either end of their stroke for at least 10 seconds to see the reactions. Reconnect the dumbells. They are push fit but will need a pair of pliers to snap them back into position.

Please let us know how you get on.

Cheers

noz

[eric]

Bingo!!!!Thanks very much for that.It's going up and down like a brides nighty now.Whilst i'm here may i ask a couple of other questions?I have a buzzing/motor running noise coming from somewhere under the o/s/f wing when the ignition is on or the car is running and also an annoying little buzzing noise coming from the interior light cluster in the roof.Any ideas,or are they noises that are meant to be there?Many thanks and regards.Eric

[John Malkovich]

The first one should be a noisy fuel pump. Worth checking.
The second noise you mention comes from the temperature sensor mounted in the front roof light assembly. There is a brushless micromotor inside which sucks the air from the cabin and on to the sensor for better and faster sensitivity. It becomes clogged with dust in time. You can easily take it off, clean and lubricate.

[neilp]

The first noise you mention is the vacuum pump for the EGR valve - is it a vacuum pump, or a compressor??
If this were a Series 1 I'd say disconnect it, but not sure of any implications with EPIC systems
Neil

[robertmnorton]

Hi all, the EPIC fuel management vehicles have a camshaft driven vac pump and control functions through the ECU.On the pre-Lucas cars the de-commisioning of the EGR system is an option as there is no control function for the diesel pump.However, if it's functioning, leave it to function.

[noz]

Hi Eric,

The noise from the front wing is indeed a vaccum pump as neilp suggests. Its only function is to operate the EGR valve. Depending on whether you believe EGR works then you have the option to disconnect it. I've disconnected the pump on both my 2.5TD's. IT will do no harm. In fact, in the cruise it will improve your mpg.

cheers

noz