Stringbag Posted October 14, 2022 Share Posted October 14, 2022 There are some excellent write ups on air suspension bag replacements, and it seems to be a common fault, so when my F07 rear end started to lower by itself overnight I thought it was a bag. The symptoms were odd though. It was Intermittent, sometimes weeks between lowering by itself but always equally on both sides. So after a bit of Googling I came to the conclusion that it was the compressor exhaust solenoid. £15 from Amazon. A bit more for genuine Wabco. (bags tend to deflate one side at a time apparently, leaving the car leaning over) This video of a bmw pump rebuild is very helpful and these people supply new o rings https://4x4airseals.com/product-category/bmw So, today was the day. Car jacked up, sound covering box put up a bit of a fight but wrested free eventually, pump removed fairly easily and disassembled. No water in the unit at all, which was unexpectedly good, but in a ying and Yang moment there are two types of solenoid my new one was the wrong one…. The old one was definitely broken as I could blow through it, so at least the diagnosis was right Hopefully new wabco solenoid will arrive tomorrow and I can finish the job 1 1 Quote Link to comment Share on other sites More sharing options...
Stringbag Posted October 15, 2022 Author Share Posted October 15, 2022 Correct one turned up this morning, all re installed, pumped back up and working. Pics below to show the two types. I think mine is a really early pump. Date stamped 2009. When I spoke to Wabco technical support they said it was quite unusual for a BMW. It was available as an Audi group spare part and Mercedes and gave me the relevant part numbers to ask for. The other, more common valve, is fitted to all sorts of cars inc land rovers. So if anyone needs a valve for a later car I’ve got one you can have. 2 1 Quote Link to comment Share on other sites More sharing options...
VPCAPTAIN Posted June 8, 2023 Share Posted June 8, 2023 (edited) Hi @Stringbagjust working through similar issues on my F11 replaced both air bags with what i thought were quality dunlop but they both go flat overnight, replaced output solenoid ( which was good ), replaced exhaust solenoid ( newer type on my 2015 wabco - again was good ) last weekend replaced all the tubing and all new brass fittings same issue flat overnight - eventually conceded the dunlop bags are poorly made at the connection point and I’m now trying two new bags ( cheap ones to test ) and genuine VOSS brass connectors - will post any sucess. But just to say i bought a used compressor off fleabay to dismantle and test before removing mine and like yours it had the older type discharge solenoid ( which is rusted stuck ) - would you be able to let me know the part no’s and where you sourced ( audi / merc ) as if i can replace it the compressor will come in handy as a spare if needs be as my compressor was dry and seals ok - suprised considering its been in heavy use daily since feb when i discovered the leak sourced the genuine VOSS fittings from germany at €5 each as against stealer £15 each Edited June 8, 2023 by VPCAPTAIN Text added 3 Quote Link to comment Share on other sites More sharing options...
Percha Posted June 9, 2023 Share Posted June 9, 2023 Good luck @VPCAPTAIN I would be interested to know if it was the air bags in the end. I changed mine back in 2020 I think with Arnott due to same problem and have been as good as gold since, I didnt change any other parts. The Arnott units feel better than the knackered BMW units they replaced. I heard many people state dont buy expensive bags, due to the cheaper units doing exactly the same job but I just dont believe they are the same quality and will last.. Hope you get it sorted soon. 1 Quote Link to comment Share on other sites More sharing options...
VPCAPTAIN Posted June 9, 2023 Share Posted June 9, 2023 (edited) Thanks @Percha i must admit the Arnott black bags look the best / im literally buying two dirt cheap bags just to test my theory its the dunlop bags bad quality inlet port thats causing the leak ( pic below ) and then going to plumb for arnott bags a long term fix. Dunlop quality control now looking into things so hoping they refund me the £230 ive even bought more new 4mm pa12 tubing and VOSS fittings in case i have to strip everything out and replace again - fingers crossed not will write a long detailed post once sorted dunlop with brass fitting sits semi recessed dunlop with fitting removed showing irregular / not smooth contact surface just prior to brass thread dunlop bag in situ bmw original plastic thread bmw original fitting is semi recessed Edited June 9, 2023 by VPCAPTAIN Add pics 3 Quote Link to comment Share on other sites More sharing options...
Andy5150 Posted June 11, 2023 Share Posted June 11, 2023 This is interesting. My f11 2015 model started to show signs of leaking bags (original factory ones) bang on 80k back in Jan last year. With it being so soon after Xmas I couldn’t afford the Arnott or Aerosus bags so went for the Dunlop too. The garage said that they only supply Arnott themselves but in comparison the Dunlops that I’d supplied seemed “ok” to to them. Wind forward 5 months and the rear on both sides is dropping again. I actually started to question whether my bags might have been counterfeit as I could t believe a brand like Dunlop would fail so soon. Anyway, I bit the bullet and paid for new Arnott bags plus a new solenoid valve to be on the safe side. 13 months on and the arnotts have been as good as gold and also, in my opinion, give a more assured and controlled ride too. maybe the issues I had with the Dunlop were actually as discussed on this thread - maybe a bad batch out there? Andy 2 1 Quote Link to comment Share on other sites More sharing options...
Andrew Posted June 12, 2023 Share Posted June 12, 2023 Having helped @VPCAPTAIN I’m watching this with interest 1 Quote Link to comment Share on other sites More sharing options...
therealmc Posted June 13, 2023 Share Posted June 13, 2023 Hi @Stringbag, another driver here with the earlier type of solenoid. I have similar intermittent drooping and expected it to be a solenoid issue so purchased one prior to removing the pump only to find I’d bought the wrong/later version. Now I have two issues: 1) since the existing solenoid wasn’t stuck (the plunger just fell out) how do you test it’s functioning correctly and 2) what is the part number to buy the correct early type? Cheers 1 Quote Link to comment Share on other sites More sharing options...
VPCAPTAIN Posted June 13, 2023 Share Posted June 13, 2023 (edited) Hi @therealmc the wabco part is hard to source ive found a oem supplier in germany and they sell the older part for €30 - ive just ordered some VOSS 4mm brass fittings and pipe from them fast delivery and €9 delivery charge and they seem genuine quality I'm just debating on buying the same part from them link below Air - release valve for compressor Audi A6 C5 allroad - Miessler Automotive GmbH & Co. KG Air Suspension Parts. - The Better Choice.pdf Edited June 13, 2023 by VPCAPTAIN Add files 1 1 Quote Link to comment Share on other sites More sharing options...
Stringbag Posted June 20, 2023 Author Share Posted June 20, 2023 Hi. I found the solenoid on eBay - it’s the same part as for a Vw. I’ll look back at my records and find out. Quote Link to comment Share on other sites More sharing options...
Stringbag Posted June 20, 2023 Author Share Posted June 20, 2023 Yes the part number 4Z01015200 is for the wabco pump fitted to an Audi Q7 and Mercedes W220/W211. I don’t have the VW or merc part numbers anymore I’m afraid but I bought mine on eBay. Arrived next day in a VW box. Quote Link to comment Share on other sites More sharing options...
Fly guy Posted February 23 Share Posted February 23 Hi Gents, Exactly the same thing happened to me ordering the wrong part, found this on Ebay to replace like for like. https://www.ebay.co.uk/itm/204622706363?itmmeta=01HQBH466WJVH37CMV2VTX4HQF&hash=item2fa476b6bb:g:sQ8AAOSwjRJlqhc4&itmprp=enc%3AAQAIAAAA8DhG036uv30RUesz8UM%2FN5iBIwuu9O2CRSgcOas5lG7y4b2c7Pfs2YbaR73sF%2FNSiz26l1%2BEme9Tpmy0rWp9gwG1ov140%2B4pooHax7kGi%2F5oulO5jD9I3PRwSQrY44y5rdxoTvI8r3qPtPAX09bftLe7CaA%2FIjNBhQyBGQyg%2FNv5tGDRQJL%2B%2Fyy4hH%2BdrGqCDeiv6hO0SztdMUhIeSBZLt5ztWcAOCV2UaYmSf5crx%2BMgfYlHomD0ngWDkurdtYOmNeAQA752x4mELEmUUrwryYzOF3c4N4NZu8YcypgNRPjrb7i6fEeQRTGOsOr9nXokg%3D%3D|tkp%3ABk9SR8TjkPG6Yw Quote Link to comment Share on other sites More sharing options...
UCB Posted March 2 Share Posted March 2 I'm getting symptoms of solenoid failure - intermittent rear end drop overnight, both sides equal and rises quickly after restarting the car. I have seen loads of repair videos re the compressor but I'm not sure how it comes out of the car or how easily. Any pointers? Quote Link to comment Share on other sites More sharing options...
duncan-uk Posted March 2 Share Posted March 2 Very easy, its under the boot floor behind the bumper - has a plastic cover which you remove and then disconnect the wires and pipes then it simply unbolts. Quote Link to comment Share on other sites More sharing options...
Hans Freekit Posted April 8 Share Posted April 8 Had the same problem - did the whole change of solenoid thing - step by step following the youtube video. Mine was water-logged inside the dessicant tube thingy. Replaced solenoid, put in back on car.. nothing. no compressor noise. It's almost impossible to fit back on the car incorrectly, so what else could it be? Quote Link to comment Share on other sites More sharing options...
ozzy Posted June 23 Share Posted June 23 Went out in car today and ride was had and didn't feel right. Got home and had a look. Both sides of the rear end are low. Started car to see if it lifted rear end, didn't lift it. Any suggestions as to what it is, would be much appreciated. Quote Link to comment Share on other sites More sharing options...
duncan-uk Posted June 23 Share Posted June 23 First off have a look at the relay i'd suggest if pump isn't activating. Its a fairly common one so you can swap it with another from the car. Quote Link to comment Share on other sites More sharing options...
ozzy Posted June 23 Share Posted June 23 Thought the relay, so ordered one. Will try that and let you know. Thanks for your reply. Quote Link to comment Share on other sites More sharing options...
HandyAndy Posted June 24 Share Posted June 24 Check the sensor arms didn't dislodge while you had the suspension dangling... very easy to do and would stop the system from firing up the compressor. Quote Link to comment Share on other sites More sharing options...
Paul morgan Posted August 26 Share Posted August 26 I had 524i 2006 bmw change week bearing while changing the sensor brake I change sensor now the pump won’t start the back on the ground could sensor the problem? Quote Link to comment Share on other sites More sharing options...
HandyAndy Posted August 26 Share Posted August 26 I would strongly suggest getting any fault codes read... Unless it's something obvious, fault codes could give you a far better idea where to look. Quote Link to comment Share on other sites More sharing options...
Matthew Posted August 27 Share Posted August 27 On 26/08/2024 at 15:26, Paul morgan said: I had 524i 2006 bmw change week bearing while changing the sensor brake I change sensor now the pump won’t start the back on the ground could sensor the problem? That's probably an E60 chassis so asking on the E60/1 page may produce some different ideas. But I agree that reading codes is your best start. Quote Link to comment Share on other sites More sharing options...
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