Member Since: 08 Nov 2016
Location: Maldon, Essex
Posts: 515
Suspension Compressor Pump Diagnostics and Sequences
Help please!
Could someone please enlighten me on the sequence of events for decommissioning D3 air suspension following compressor replacement.
I have an IID but other than gallery pressure and motor temperature, I'm unsure of what to watch.
I'm guessing the reservoir should fill up first then the various valve blocks should operate and distribute the pressure to the suspension air bags.
How long should an initial fill of the system take before something happens?
What pressure should I see in the reservoir?
Should it keep whatever pressure it makes or drop away again when engine turned off?
Thanks in anticipation.
MikeyNot such a Disco Newbie now!
IID BT
15th Jul 2019 3:04 pm
Admirable
Member Since: 19 Jul 2015
Location: Fife
Posts: 1007
Do you mean RE commissioning?
15th Jul 2019 4:14 pm
Mikeyb
Member Since: 08 Nov 2016
Location: Maldon, Essex
Posts: 515
Re-commissioning following compressor replacement and front valve block clean out.
I suspect that there is not much air left in the system as the car is sitting on its bump stops.
So I am in the process of trying to free off the seized bolts holding the air tank on, if I can drop that, then I will douse it in soapy water to try and eliminate it as a source of leakage.
It looks like there only one pipe connection to the reservoir which must be an in/out.Not such a Disco Newbie now!
IID BT
15th Jul 2019 5:26 pm
Mikeyb
Member Since: 08 Nov 2016
Location: Maldon, Essex
Posts: 515
I am also concluding that the valve block next to the compressor is the main source of air distribution to front/rear/reservoir. Does anyone know if it can be controlled via the IID to pressurise each part individually in turn?Not such a Disco Newbie now!
IID BT
15th Jul 2019 5:31 pm
Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10335
You just start the engine.
That is it!
Wait 2 mins and then ask car to raise if it hasn’t.
15th Jul 2019 6:35 pm
garfield2
Member Since: 24 Jul 2008
Location: morley, leeds
Posts: 310
The reservoir will take some filling then the gallery needs air, the valve block by the compressor does indeed control much of the air demand, mine was dropping overnight on the rears, now all three valve blocks have been resealed it stays up, however that damm pesky yellow suspension light pops on within 800 yds of setting off for work, resets whilst at work then might not pop up for a day and half then bong, back on 😱😱😱
So today I’ve ordered a new tank from duckworths at market raisin and a relay, total illogical reason to have a new relay but every connection all the blocks and now the tank to be replaced there is only a13 year old relay to check out.
The code keeps repeating that reservoir is slow to fill yet pressure jumps from 190 Kpa with compressor temp at 86 and motor temp at 89 to a whopping 1370 Kpa till temp reaches 120 at comp and 130 at motor then comp stops.
Discovery 4.5 HSE 2015 MY
Discovery 3 SE 2007 MY gone with spinning journals
15th Jul 2019 8:51 pm
TuppyTrucker2
Member Since: 30 Dec 2013
Location: Basse Normandie
Posts: 16
Re: Suspension Compressor Pump Diagnostics and Sequences
Mikeyb wrote:
I have an IID but other than gallery pressure and motor temperature, I'm unsure of what to watch.
Mikey
Gallery pressure
Compressor temp - motor temp is irrelevant. The comp cuts out at 130C
Reservoir valve %
Exh Valve %
Compressor relay state.
Then you can see then the comp comes on, what the gallery pressure is and when the valve opens to fill the tank, and the exh valve open to vent the gallery.
Max pressure is 17.6 bar
The pressure sensor is on the gallery side of the reservoir valve, so you'll only get a tank pressure reading when the reservoir valve is open. A good compressor will raise the gallery pressure by 2 bar / min or more, while the valve is open.
The system schematic should help. It's in this photo album.
http://bit.ly/HitachiD3LR: D4 3.0 auto, D3 2.7 auto, D1 2.5 auto, D1 2.5 man.
Skoda: 2017 Kodiaq Edition 180Tsi 4wd DSG
#CafeGruff #BinkyBistro
16th Jul 2019 2:26 pm
TuppyTrucker2
Member Since: 30 Dec 2013
Location: Basse Normandie
Posts: 16
[quote="garfield2"]a whopping 1370 Kpa till temp reaches 120 at comp and 130 at motor then comp stops.
You're way short on pressure. A full tank is 17.6 bar.
If yours stops at 13 then you've got a leak, either in the drier or the tank.LR: D4 3.0 auto, D3 2.7 auto, D1 2.5 auto, D1 2.5 man.
Skoda: 2017 Kodiaq Edition 180Tsi 4wd DSG
#CafeGruff #BinkyBistro
16th Jul 2019 2:29 pm
Mikeyb
Member Since: 08 Nov 2016
Location: Maldon, Essex
Posts: 515
Thank you for this reply, it was most helpful!
Well, what a saga it turned out to be. New Dunlop compressor purchased from
...which was subsequently lost by DHL. Another new compressor purchased and fitted (before I read replies to this thread), I eventually got the vehicle to pump up by selecting the test function on the IID and raising each corner in turn, never thought of flicking the control switch, doh! I have since also found the re-enable EAS function in the IID menu which may also have done the same thing!
However, my pain did not stop there. The next morning I was greeted by a car with its in the air and its front on the ground. Not happy! Yet another buzz around with the soapy water spray eventually detected a leak from the n/s/f strut air bag. So hand in pocket again and new strut fitted.
Upon completion, car was very reluctant to pump up again. More fiddling with the IID menus eventually got it back in the air again. Switched off the engine and walked around car heading back to house for complimentary coffee, only to hear a distinct hiss from the nearside. Back under with the soapy water again to find that the air tank had now sprung a leak! Note: no hiss or soapy bubbling on any of the previous diagnostic checks so guessing the better output from a new compressor in a more leak free system finished off an existing weakness in the old.
So much cussing and hand in pocket again, fingers crossed with the fitment of the new tank, the car has stayed pumped up and alarm free for a couple of days now. #feelingpoorNot such a Disco Newbie now!
IID BT
15th Aug 2019 9:13 pm
Mikeyb
Member Since: 08 Nov 2016
Location: Maldon, Essex
Posts: 515
....and the (hopefully) final update - suspension ECU software upgraded without drama and so far it has behaved itself with suspension staying pumped up, raising and lowering on demand without bringing up the usual faults and a long trip towing the caravan.
Wishbone replacement next, wish me luck, lol!Not such a Disco Newbie now!
IID BT
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