Air suspension pump testing.

[DAVE39V8]

Can anyone tell me what the 3 wires to the classic air suspension pump are..?
Without looking I think they are green/orange/black???
I have just changed mine and want to test my old one by connecting it to the battery and dont want zap myself or something. :oops:

Dave :)

[pongo_bob]

Not sure of the colours mate. I stripped down my 110 K miles compressor and although the piston seal was 'tatered the rest of it looked pretty good. The brushes were probably about a third worn. The piston seal was split and there was a yellow dust inside the pump chamber.

If you pull the motor apart it's a [!Expletive Deleted!] to get it back together again as the brushes pop out . I made a couple of hooks out of MIG wire to hold the brushes while I wiggled the motor end cap back on. Even so it took a while.

[Range Rover Blues]

Black, earth, green motor IIRC, red temp sensor.  For sure one of either green or red is thicker, this is the one you want.

[DAVE39V8]

thanks RRB least i can check my old one..the rangie is in being checked out at the mo..i changed the pump/compressor and they just phoned me to say it still not working and ECU showing no faults..
waiting for the them to try trace fault now..loadsa money

[DAVE39V8]

Got Rangie back from ECU fault clearing....and.....the faults are cleared but the pump still not working..
Now,I have checked my old pump that I removed first,connecting green/black to battery and it worked..
So I did the same to the "second hand" pump in situ and that worked too(now I am puzzled).
I've had the pump on car running for a minute or two by connecting the wires straight to battery but it didnt seem to pump up the suspension.

How long can the pump be run like this only I dont want to run it too long and burn it out.. :?:  :oops:  :?:

Also what else could be wrong now :?: :?:

[Range Rover Blues]

The red wire IIRC goes to the pump overheat sensor.  If that fails the ECu will run the pump in short bursts to protect it.

If you run the pump for a for a while you should get some air into the tank but be careful you don't over-inflate.

It is possible that the pressue switch is stuck, the ECU would think the tank is full and not run the pump as a result.  This won't show up as a fault, not for a while at least untill the ecu thinks all that air (that doesn't really exist) is leaking on it's way to the air bags :roll:

Whoever tested your EAS should have checked that the pressure switch was changing state, ie on-off.  If they havn't then there is one to check.

[DAVE39V8]

Do you know where this pressure switch is located and is it easy to fix/change :?:  :?:
I had pump running like I said but nothing seemed to happen to the height.    :?

[Range Rover Blues]

OK I had a quick look at the system schematic and there is a pressure relief valve so you can't over-inflate the system.

If the system is totally flat the pump needs to run for at least a minue before there is enough pressure to lift the back end, remember the back end will lift first.

IIRFC the pressure switch is located on the tank but I'll go check that.

One way to check for pressure in the system would be if you can open the drain valve in the bottom of the tank, it needs a very big allen key though.  Just crac it open, the bolt has a channl cut into it to relief pressure and blow out water without blowing the plug out.

[Jonny Boaterboy]

I'm not sure about this but I think it takes 6 min to fill an empty tank as Mr Blues said you can't over inflate so leave it running for a while with the door open or inhibit switch on (under drivers seat) then close the door and see if it works. If you send me a PM with your address I have a very helpful few pages I found on a web sight which I can drop in the post to you, it tells you in detail how the air works and common problems and fixes

Let us know

Jonny

[DAVE39V8]

I'm not sure about this but I think it takes 6 min to fill an empty tank as Mr Blues said you can't over inflate so leave it running for a while with the door open or inhibit switch on (under drivers seat) then close the door and see if it works. If you send me a PM with your address I have a very helpful few pages I found on a web sight which I can drop in the post to you, it tells you in detail how the air works and common problems and fixes

Let us know

Jonny

The pump doesnt run unless I connect it straight to battery.
Wont the ECU pick up a fault again when inhibit switch turned on :?:

PM sent.

Dave

[DAVE39V8]

OK I had a quick look at the system schematic and there is a pressure relief valve so you can't over-inflate the system.

If the system is totally flat the pump needs to run for at least a minue before there is enough pressure to lift the back end, remember the back end will lift first.

IIRFC the pressure switch is located on the tank but I'll go check that.

One way to check for pressure in the system would be if you can open the drain valve in the bottom of the tank, it needs a very big allen key though.  Just crac it open, the bolt has a channl cut into it to relief pressure and blow out water without blowing the plug out.

I've just had quick look..There is no power getting to the compressor or the pressure switch(checked with bulb technique etc).
I have checked fusebox and all fine.
Haven't found an allen key big enough yet for the tank..

I tried pumping up susp just connecting compressor to battery and no height gained.
But when using the inflation kit(which is fitted on each corner seperately)the bags fill up individually as inflated. :?:

Patience is wearing thin    

[Range Rover Blues]

I'm not sure about this but I think it takes 6 min to fill an empty tank as Mr Blues said you can't over inflate so leave it running for a while with the door open or inhibit switch on (under drivers seat) then close the door and see if it works. If you send me a PM with your address I have a very helpful few pages I found on a web sight which I can drop in the post to you, it tells you in detail how the air works and common problems and fixes

Let us know

Jonny

Wouldn't mind a copy myself.

[Range Rover Blues]

Ok let me get this straight.  

1]You can make the pump work by connecting to the battery but no power comes from the ECU to the pump.

2]Even after you have run the pump to fill the air reservoir the suspension will not go up.

3]You can manually inflate each corner in turn so you are happy there are no leaks between the valve block and the air springs (at least no fast leaks).

1] if the ECU thinks the tank is full it will not run the pump, so I still think it could be the pressure switch.  If you can get hold of the wiring diagram then you could test the output from the switch with a multimeter.  If you can find the switch you could manually over-ride it with say a blade type fuse or paper clip.

2]How long did you run the pump for? are you sure the pump is building up pressure and not leaking internally?

Do you hear the valves open and close (ticking) as it tries to inflate the corners? can you hear it self-leveling if you inflate each corner manually?

This last point is important, if the system is not self-levelling, say after you turn off the ignition or close the last door then something may be wrong. So what does your car do if you inflate the suspension manually, this may be a clue.

BTW, the inhibit switch just works like a door open switch, it suspends the EAS below 50mph.  Check that yours is not inhibited, the garage may have done this at some point.


If you fancy a drive up then I will put it only Rovacom for you and try to get to the bottom of it.

[Jonny Boaterboy]

Mr blues, I have just don a copy for Dave I will try and get one do for you next week (read you note after doing Dave's copy!)

send us a PM with your address

Jonny

[DAVE39V8]

Ok let me get this straight.  

1]You can make the pump work by connecting to the battery but no power comes from the ECU to the pump.

2]Even after you have run the pump to fill the air reservoir the suspension will not go up.

3]You can manually inflate each corner in turn so you are happy there are no leaks between the valve block and the air springs (at least no fast leaks).

1] if the ECU thinks the tank is full it will not run the pump, so I still think it could be the pressure switch.  If you can get hold of the wiring diagram then you could test the output from the switch with a multimeter.  If you can find the switch you could manually over-ride it with say a blade type fuse or paper clip.

2]How long did you run the pump for? are you sure the pump is building up pressure and not leaking internally?

Do you hear the valves open and close (ticking) as it tries to inflate the corners? can you hear it self-leveling if you inflate each corner manually?

This last point is important, if the system is not self-levelling, say after you turn off the ignition or close the last door then something may be wrong. So what does your car do if you inflate the suspension manually, this may be a clue.

BTW, the inhibit switch just works like a door open switch, it suspends the EAS below 50mph.  Check that yours is not inhibited, the garage may have done this at some point.


If you fancy a drive up then I will put it only Rovacom for you and try to get to the bottom of it.

Here we go....
1)Correct!
2)Correct!
3)There is a leak but a slow one.

I will try the paper clip method in morning.

I ran the pump for approx 1.5mins so might not be long enough.

I haven't driven it with the inhibit switch on while pumped up manually(because I know it will lower itself eventually on bump stops :?: ) but it drives ok.

When I picked the car up from getting the ECU faults cleared they said it were all pumped up(manually) and ready to drive home but when I got to car it were on bump stops(from it self levelling over the few hours stationary).
They had to pump it up manually so I could drive home(with inhibit switch off).
So I would say the self level/opening door aspect were ok.

I will have another go in morning and let you know how it goes.
If it doesn't work then expect me in Sheffield  :lol:

I hope all this makes sense only trying to write this and stay awake to do a nightshift is abit tiring(especially when during the day i'm under the car and coming up against a brick wall) :)

[Range Rover Blues]

Ok, there's some good new then, if it's self levelling you should be able to hear the valves opening but at least they work! along with the exhaust valve.

So possibly the inlet valve is stuck/broke or it's back to the pressure switch.

Meanwhile I'll have a trawl through the Rovacom forums

[DAVE39V8]

Right had ago with the paper clip on the pressure switch and still nothing..
I left pump connected to battery for 6min and still nothing (as in height)but I did hear slight ticking from the valve block(approx 2ticks per second).

I drove it to my nearest petrol station on the bump stops to fill with air(my tyre pump not working now,tut,just my luck)and it hardly went up an inch.But where did all the air go I put in... :?:

My neighbour works for a commercial firm and said I can pop there in the morning to try put some proper air in it :)

I did try opening/closing the door with the inhibit switch on and it didnt self level but that might be because it were low anyway..

I'm determined to get this sorted and not convert to springs..... :(  

[Range Rover Blues]

I did try opening/closing the door with the inhibit switch on and it didnt self level but that might be because it were low anyway..

I'm determined to get this sorted and not convert to springs..... :(  

The inhibit switch on? if it's in the centre it's off, if it's down then it's on.  All it does is mimick a door being open.  Put it in the centre if you havn't tried that already, then when you shut the last door it should self-level (ignition off) but I guess you know that.

Once you have pumped it up you say it goes down due to a slow leak, which corner out of interest.  If you leave the inhibit on overnight you will see the offending corner sink to the floor.

Anyway, assuming the pump isn't goosed (a possibility) then there must be something else inhibiting the EAS.  The brake light switch is another suspect.

[DAVE39V8]

Hello again RRB...

I managed to get it off the bump stops today and as I was pumping it up at the front drivers side(with the inhibit switch in the centre position)the car self levelled when the front got to a certain height with air being sent to each air bag.
So didnt need to pump up from the rear.

As the door was open/closed the car levelled itself with the ticking from the valve block auditable.
I'm happy the self levelling side works fine.

There just doesnt seem to be any life going to the pump or the pressure switch(which I tried again with the paper clip to no avail).

If left overnight with the inhibit switch in centre pos it levels itself as it should every few hours and goes down level.
If left overnight with the inhibit switch down the rear is close to the bump stops in the morning.

Been driving it around all morning with the inhibit switch down/off and it been fine..

Could we be getting somewhere :?:  :lol:

[Range Rover Blues]

Yes that sounds very encouraging, particulary that it 'found' some air in the tank to raise the back end and that it was able to raise under ECU control, that's all working.  The inhibit switch is just fine too.

This must have come from the tank, there is no way that air from the front bags can get into the back unless you are using a Diagnostic, so that must have been in your tank.  Sounds like the pump is doing it's thing when you connect jump leads to it.

So we still have no power to the pump, and it sounds like no power to the pressure switch (obvioulsy you found it, where was it?) did you check that with a test lamp or a meter?

I'm going to have to get a circuit diagram out and look at it now but it's going to be something silly, you'll laugh when you find it I'm sure

[DAVE39V8]

The switch is in the tank or am I wrong and tested wrong one :oops:
I tested this switch like I did the pump feed with the bulb test(dont possess a multi meter of some sort)

Like you say it going to be something really silly now I know it :lol:

Thanks for taking the time to help out here  :)  :)

[Range Rover Blues]

Ok, on that switch you must have checked to see if either wire was live and you stuck a paper clip in the wiring plug too.

Did you try it with the switch disconnected ie open circuit?

The other thing we need ot check is the temp switch on the pump, although if it's faulty the ECU should run the pump in short bursts.

[DAVE39V8]

I'm not sure if I tried with switch disconnected I think I did :oops:
Where would the temp switch be for the pump..
That would be understandable considering the pump were running to pump air into a burst bag(I never knew about the inhibit switch at the time). :oops:  :oops:

[Range Rover Blues]

The temp switch is the red wire going into the pum itself whether it opens when it's too hot or closes I don't know off the top of my head but those are the 2 things that spring to mind for the pump, assuming you have traced all the fuses and I think you said you had already :?

[DAVE39V8]

I have checked main fusebox and they all ok..
Where else is there likely to be fuses hidden.. :?:
Whats the big 30amp fuse under seat :?:

[Range Rover Blues]

Now you are asking.  I think ther may well be one for the pump under there.  I have a snealking suspicion there may have to be a relay as well, though I never hear mine click on and off. Otherwise the ECU is handling about 12 amps, that's what the pump draws off my battery charger.

[DAVE39V8]

Just took a gander at the handbook and the 30amp fuse is for the air suspension compressor(maxi fuse)..Will check this 2mrw.

Is there anymore fuses I should search for incase that one ok:?:
Like I said before I appreciate all this help.

[Range Rover Blues]

Now I really need to go look at a manual

I'll get back to you soon.

[DAVE39V8]

Ok RRB thanks again

[Range Rover Blues]

Right, if you found a 30 amp fuse under the seat then keeping it company are a large relay that gives the EAS a 30 second delay to self-level after turning off the ignition, a 5 pin relay that runs the warning light on the dash and a 4 pin relay that runs the pump itself :)

THis relay needs checking, even if it's just to see what's going on.

The pressure switch is if I understand correctly open circuit untill the pressure reaches 10 bar nominal, it stays that way 'till the pressure drops to 8 bar.
So if you disconnect it the pump should run.  Sounds wrong to me as there is no failsafe in that logic, but that's the way I read things from the manual.

The temp switch is better, it goes open circuit when the pump clears 120 degrees (ouch) and it goes to earth, so you need to check the continuety of the red wire on the motor to earth, if the contact is broken the pump won't run, so try shorting the red wire to earth.

If you are still struggling then I have found the pinout of the ECU for you, you will have to check through it in order to check what's going on.  You can also use it to manually inflate the EAS if you can get the pump to run.