hi all

i am in england (greetings!) and have a 1995 w124 e320 coupe (110k miles).

PROBLEM:
the seatbacks no longer lock (with the engine running and doors closed) - the headlight aim adjust and rear headrest release also have ceased to function. major problem as this fails the annual roadworthiness test so cannot use the car

remote central locking and full-closure alarm still works fine. knock on wood!

HISTORY:
i am unsure when they all stopped working - it could be old age - but in the last year i have replaced the headgasket (and maf), put a replacement leather interior in and replaced a headlight and the battery - any of which could have disrupted the circuit or cracked a pipe!

i've figured roughly how the system works and.....
- i have located the pumps and actuators under the rear seat and identified some of the pipes.......
- sucking hard (!) on each white pipe released each rear headrest
- i have tested each seat mechanism (by sucking the pipes again!) and both work ok afaict
NOTE: i did try using a syringe - but not enough suction!!!

haynes manual - useless, TIS cd - not much use, searched the forum and found snippets of information (mainly re the central locking vac circuit) and some confusion (ie is there a reservoir? non-return valves?)

HELP!!:
what i really need is a vacuum "circuit" diagram to identify the key components and the pipe color codes so i can and work through systematically without ripping the whole interior out (again!)

i am hoping that if i know the source of the vacuum and subsequent routing i can start at the source and find where the vacuum is lost or component has failed........

i know a "mityvac" is recommended but i don't know if available in the uk. how much vacuum is generated? - could i adapt my carb-balancing vacuum gauge? or could i use a big syringe?

i am happy to pay for the info or be pointed at a manual i could buy in the uk - maybe i've missed the section on the mercedes cds !!?

merc dealers are $240 (£120) per hour in my area so i am keen to trace it myself!!!!!

thanks in advance for any help

 

your merc

[IMG]local://upfiles/1/2AE31F2FD30942B6B8528104FBB3C481.jpg[/IMG]

[IMG]local://upfiles/1/1A8A3EFCC3D740459579006B78DE2660.jpg[/IMG]

 

hi sleepwalker

that is fantastic ! many many thanks ! i think i can figure the colours out from this

at the risk of looking a gift-horse in the mouth can you/ anyone answer supplimentary questions .......

what manual or cd need to give me this info?
do both diagrams refer to the same component under the rear seat? i assume so
and is this what generates the vacuum (again i'll assume so) or are the pipes (14 and 26 respectively) attached to a pump or the intake manifold in the engine bay?

again thank you - i'll make a start this weekend and advise of results

John C.


incidentally, and purely for your/others' information in the spirit of feeding something back:-
- my car has 2 lines out from the component - one for each rear headrest - so no "Y-splitter" under the rear parcel shelf as shown in the diagram
- the pipes to the rear headrests are white with blue stripes
- the seat pipes seem to be blue
- the headlight pipes are pink

will post more as i find it

 

Hi

I had the same problem..it's definitely a vacume leak...but it may not be inside the car. I located mine in the engine bay. There is a of group of vacume tubes coming out from the engine bulkhead (from the interior of the car) into a mix group of (what I would call `valves') and multiway rubber tube connector. This is just above the brake master cylinder and near the fuse box. Check the condition of this section. There is one tube (connected to this) that run across the width of the car and under the wiper motor assembly. It ends up being connected to the inlet manifold, near the throttle cam and on the other side of the car. This tube is exposed to a lot of heat and could perish. The only way to check it is to disconnect it and yank it through. BUT there is no easy way to push it back without take stuff off (you'll know what I mean, when you do it). I just let it rest on top, instead of trying to thread it underneath.

Hope this helps someone.
Shiru

 

Oh and nearly forgot...

DOES ANYBODY know the function of the above 'valves', with reference to my previous post. These are valves that are connected to vacuum lines 26 and 14 in the above diagrams.

I'm assuming they are valves of some kind.

Can anybody confirm this?

I have a problem: even with fixing the hole in one of the tubes..I cant get the economy guage to move all the way to the left (i.e. highest economy) when idling. This I believe it the correct behaviour of the guage. It only moves to the left when decelerating.

Many thanks
Shiru

 

on the top of the brake booster?

it's a check valve for a/c.

i think the other end goes to economy gauge?

[IMG]local://upfiles/1/9132C34032B547A2B4354D664BC59C5C.jpg[/IMG]

 

I have similar problem. But the Diagrams are no longer visible.
Can anyone help?

 

I would love the see the diagram but it's only showing some kind of link?