Central locking delay on 107

[coleyjf]

Hi all

I've decided try to to fix a longstanding problem on my Euro(UK) 107 300SL. I think I know what the problem is but thought I'd ask for guidance as to the BEST place to start.

Problem:

LOCKING: when I operate the central locking from any of the three locks -doors and boot (trunk) the vacuum pump runs for ages after the car is locked but it does lock ok.

UNLOCKING:When unlocking with either the remote key fob ( factory fitted alarm) or one of the locks, mostly only one lock un-locks and although the pump runs a while it doesn't seem to work all three locks - the locks all work OK manually.

My thoughts:

I guess there's a leak in the vacuum system somewhere - possibly the drivers door hinge as I guess it gets most use?

MY QUESTION (sorry to be longwinded) do I start at the drivers door or has anyone a better suggestion ( I've already looked at the pump itself and checked the pipe connections)

Look forward to your help

Cheers

Jim

[Lexxani]

its possibly the vaccum distributer for the lock system (behind the driver's side door skin) is faulty. Id begin there. If thats the flaw, its a cheap fix, the part is redily available on ebay.

[coleyjf]

Thanks Lex....

One thought before I start to take the door(s) apart, as it's a UK model (Right Hand Drive) will the Vacuum Ditributor be behind the Right Hand door (UK Drivers door) or the Left Hand Door (US & European Drivers Door)? My guess is Right Hand Door (UK Drivers door) as the MB engineers seem to have switched everything else over OK for the UK model.

Also anyone give me a quick link to the best post on taking the door to pieces without damaging anything - I've done a search but there seems to be loads of threads on this all a bit different.

Cheers and thanks for the Help

Jim

[JimFreeh]

Get a mighty vac and do some troubleshooting.
Old Benz have lots of potential for vacuum leaks.

Might be cheap (hose), might be expensive (actuator).

Got to check it out to verify.

Jim

[karburn]

I had the exact symptoms on my 87 560SL. It turned out to be the locking unit for the fuel door. $23 and I replaced it myself. The housing on the old one had cracked, probably due to the way they are mounted. I found it by leaving the trunk lid open and then locking the car with the key. Since the pump kept running for a while, I was lucky enough to find the source of the leak before it shut off.

[el duque]

I'm new to working on these cars, and have no experience with these vacuum sysems, but I am restoring an 81 300SD that has been sitting in a field for quite a while. Anyway, I have a similar problem with the vacuum pump in the trunk. It runs constantly, even with the key out of the ignition. Am I looking at a leak? and if so, is it difficult / expensive to fix? Thanks

[lynns]

Originally Posted by karburn

I had the exact symptoms on my 87 560SL. It turned out to be the locking unit for the fuel door. $23 and I replaced it myself. The housing on the old one had cracked, probably due to the way they are mounted. I found it by leaving the trunk lid open and then locking the car with the key. Since the pump kept running for a while, I was lucky enough to find the source of the leak before it shut off.

I to found my problem to be the fuel door vacume assembly that it is found in the trunk on the right hand side behind the paneling.

[coleyjf]

Thanks Guys

I'll try the fuel door - I never thought of that one

Door Panel Removal help "Please"!

I did start taking the door panel off yesterday but came across 2 problems - normally on my other cars I've never had a problem taking panels off but I'm trying specially hard not to damage anything.

1: Where the panel edge was fixed to the entry to the heating/ventilation duct (which goes up to heat the side window) on the hinge side of the door above the plastic poppers. This Seems fixed tight but I can't see where or how and as it's a 20 year old plastic duct I didn't want to force it as I thought it might break! Possibly this heating duct arrangement is on the "86 Face Lift" only.

2: How do you remove the "inner door catch" handle and trim?

Still looking for a good link for this one.

Cheers

Jim

[coleyjf]

well I've discounted the fuel door

Did it the easy way - just by passed the unit it with a "TEE" piece pipe from my greenhouse watering system and the fault still there - so off with the door panel for the next step.

still looking for a good door panel removal guide

Cheers

jim

[JimFreeh]

Originally Posted by coleyjf

well I've discounted the fuel door

Did it the easy way - just by passed the unit it with a "TEE" piece pipe from my greenhouse watering system and the fault still there - so off with the door panel for the next step.

still looking for a good door panel removal guide

Cheers

jim

Get thee a "Mighty Vac". It's indispensable for finding the source of the leak.

Jim