Central Locking - Air Pump

[wez.k]

Hello all. Its a long time since I have been on here, but I just wondered...

After 58,800 trouble free miles, my SLK230 suddenly locked me out of the boot - then it locked me inside the car - then it let me out and locked the boot again. Dealer said it was the 'Air Pump' and fitted a new one for the sum of £493 including labour.

Now I know the car is 7 years old, but its well below average mileage, and I would have thought that a high cost component like that should not fail at this time in the car's life. My previous two cars (Toyota's) have run over 120,000 miles with no trouble at all, and I expected as good if not better from MB. I am currently corresponding with MB cutomer service on the subject

Anyone out there had similar trouble with this?

 

[television]

Sadly with this type of car you will have some problems mainly due to water damage, these pumps never fail on the fixed head cars, its just one of the joys of open top motoring.

malcolm

 

[battwell]

annoying to pay that much for a pump when its usually only a bad solder joint or two. ive had these give problems on every merc ive owned!:-(

 

[David in OZ]

New here.....but have some info that might help others to prevent this common SLK problem

Blocked drain (Driver's side for RHD) is the usual cause......water drips down lines connected to PSE unit......some have tried wraping it in plastic.....but usually not effective unless 100% seal of water tracking down lines....can end up just collecting moisture

The fix for early model SLK's is to install the PSE (Air Pump & electronics) upside down.......needs extenders for connections......later models come this way

This is a link to a Star Bulletin (difficult to read on my laptop, but prints ok)

http://www.alldata.com/tsb/Mercedes-Benz/1078819200000_1083135600000_P-80-00-25/images/251.gif

wez.k......you might have a warranty claim if you have one of the problems listed on the bulletin......chances are they will just blame lack of regular clearing of drains :x

Not sure about the ethics of refererring to another Forum.......but these threads from a US Forum give good information courtesy of another Aussie

This is a fix if you don't want to invert it

http://www.benzworld.org/forums/r170-slk-class/1270676-pse-removal-refit-check.html

Info on clearing out drains

http://www.benzworld.org/forums/r170-slk-class/1300402-rear-drain-problem.html

Cheers

David

 

[television]

Hello David and welcome to the forum, I did not think that you had rain where you are The lnks and info are good to have and thank you for the info.
Makes you wonder why they did not fit them that way from the start.

Malcolm

 

[wez.k]

Thanks

Thanks for that guys.

I hadn't considered it, and the boot has always looked dry, I've never seen any water inside it, but then again, I haven't looked under the carpets!

The unit they took out looks OK at a glance, but on closer inspection, yes there are signs of corrosion in one of the connectors, so I guess you are all on the right track.

Haven't heard back from MB yet, but now I have some more ammunition!

 

[djlew]

I know it's not much help now but second hand pumps are relatively available and certainly on my 300SL easily fitted. I know because I've an ongoing problem which is not the pump which I'll be posting soon looking for help.

 

[eric242340]

Central locking air pump

Not much help, but its a common problem on almost all the models. The bigger models suffer doubly as they also have a door assist pump and it can easily be overworked. Usually by a simple vacuum leak on one of the pipes and then the tiny motor inside it burns out. Here we repair them and put em back, that really annoys the hell out of the dealers.

 

[Pipemaster]

Not much help, but its a common problem on almost all the models. The bigger models suffer doubly as they also have a door assist pump and it can easily be overworked. Usually by a simple vacuum leak on one of the pipes and then the tiny motor inside it burns out. Here we repair them and put em back, that really annoys the hell out of the dealers.

My SL sounds a bit asthmatic and takes ages to unlock the filler flap and the central console lock whirring away for quote a while after I get in - although this improves during the day - is there something I should look at before it all goes west like a leak.As it gets quicker duuring the day i.e. more frequent use - is it losing pressure or does it have a leak would you think?

 

[eric242340]

Air pump

My SL sounds a bit asthmatic and takes ages to unlock the filler flap and the central console lock whirring away for quote a while after I get in - although this improves during the day - is there something I should look at before it all goes west like a leak.As it gets quicker duuring the day i.e. more frequent use - is it losing pressure or does it have a leak would you think?

Sadly yes it is leaking on one of the pipes/components. The longer the pump wirrs the more likely it is to damage itself. But to test for leaks you will need a vacuum tester and this means removing the pipes from the pump one at a time and testing with the vacuum guage. Once you find the one thats leaking you will need the vacuum diagram to trace the component this pipe goes to and thus you can then check the component to decide if its a pipe leak or a component leak. For some strange reason ive found, the older the car the more likely it is the boot lock.

 

[Pipemaster]

Thanks for that I did wonder. the vaccum pump is under the drivers side rear seat I believe so at least it's not to hard to get to it. The boot lock soemtime fails to unlock at all early in the day or after being left even with the remote boot button on the key and the dash, so I believe you to be right

 

[djlew]

Just sorted a vacuum problem, pump running for ages when Central Locking used, and yes it was the boot lock!. However all I did to ID the source was to remove a pipe from the pump block end with finger and use Central locking. When you find a pipe that when blocked with finger lets pump run for a second or two you have the culprit. Located boot central lock behind a cover plate next to the lock and found the air/vacuum pipe had worked a fraction loose, could hear it sucking and blowing when locks activated. Couple of twists of the air pipe, seal restored and all's well. Hope yours is as simple.

 

[television]

Nice to know that both of those 2 cars are fixed, and both faults in the same place.

Malcolm

 

[eric242340]

Central locking air pump

I like your diagnostic method, it differenet but it brought results, and good to see both fixed.

 

[Pipemaster]

I will try that and let you know but it sounds promising I must say i wonder if the fuel flap lock tee's off the pipe to the boot lock.....

 

[wez.k]

MB Customer Service had a look at the stuation and decided to have the dealer refund me £300. Havn't received it yet though.
I intend to clean up the contacts on the old pump and put it to the test. If it seems OK I might have a pump for sale...

 

[Pipemaster]

I need a pump

Stealers just told me that the vac pump has been damaged by water.... we are going to check the seals around the boot lid etc. £290 plus if anyone has one for sale let me know please

 

[television]

Stealers just told me that the vac pump has been damaged by water.... we are going to check the seals around the boot lid etc. £290 plus if anyone has one for sale let me know please

I understand that these can be fixed, I will be sure in a few days time.

malcolm

 

[eric242340]

Air pump

I understand that these can be fixed, I will be sure in a few days time.

malcolm

Yes they can Malcolm, we fix them all the time. Its normally a case of replacement electric motor and these are quite easy to buy:razz: :razz:

 

[Pipemaster]

OK its in the workshop at the momnent and I have let him know these can be repaired and he's going to have a look. in the meantime can you see if my logic is correct.
The pump activates all the locks including cubby holes fuel cap etc. I don't have any trouble locking and unlocking the doors but all other locks take time. I assume that the system remains under some sort of pressure so long as there are no leaks. The time taken to unlock all the other ancillaries is probably because the pressure in the system has dropped in between operations e.g. overnight, and the motor overworks to repressurise the system and for some reason the door locks get sorted first.
Could it be that the motor is on its way out and so doesn't get the system up to pressure enough to be sustainable which replacing the motor will fix
or
is the system likely to have pressure leak(s) which needs to be found and sealed and in the interim the motor has been damaged from over work and will still require replacing
or
The pressure leak or leaks is / are causing all the problems and once sealed the unit will work as it should...

or any other suggestions

Sorry its a diatribe but I just gotta know