E320 coupe seat back

[MotardMan]

Passenger side does not flip forward when the release button is depressed. Any ideas what could cause it? The drivers side is fine.

 

[c955]

Is this when the car's moving or stationary?

It's only supposed to tilt forwards if stationary - though I assume you know this?


PS. Very nice choice of 'new' car, though are you sure it's 'bormite' in colour?

PS2. Did you buy your coupe from the South coast/Brighton?

 

[MotardMan]

Car was stationary, and I tried it with ignition on, and off.

Bormite is the colour, it is a kind of dark purple metallic?

The car came from Ferndown, near to Bournemouth. Thanks for the reply, appreciated, do you tink it may just be the vac line, or the actuator?

 

[kth286]

Motardman

It has been seen that when there is a problem with the seat folding on coupes, because it is so critical to passing the MOT, in their rush to fix it and pass the MOT, the seat has been permanently fixed by a stout wire around the bracket.
Perhaps that has been done to your car and the original problem is the vacuum system, which still needs fixing.

Is the vacuum also connected to your door not working ???????????

 

[MotardMan]

Motardman

It has been seen that when there is a problem with the seat folding on coupes, because it is so critical to passing the MOT, in their rush to fix it and pass the MOT, the seat has been permanently fixed by a stout wire around the bracket.
Perhaps that has been done to your car and the original problem is the vacuum system, which still needs fixing.

Is the vacuum also connected to your door not working ???????????

Good point, I did not think to check that, but will when I get the car home.

Vac to the door? The c/l on both doors works fine, but not from the key fob button when pointed at the door handle on the drivers side.......

 

[Apial]

I usually have to explain to the MOT tester how the seat tilt works. It is only supposed to lock the seat back when the engine is running and all the doors are shut. You should therefore only need to press the release button if you are a rear seat passenger who has been left in the car with the engine running, doors all shut, and you need to get out.

Switching the engine off, or opening a door, will release the locked seat back auto matically.

Sounds like perhaps someone has over-ridden the system and locked yours permanently. The trouble is usually that the vacuum pipe has come adrift and the seat wont lock at all. Using wire is a naughty bodge.

 

[MotardMan]

I usually have to explain to the MOT tester how the seat tilt works. It is only supposed to lock the seat back when the engine is running and all the doors are shut. You should therefore only need to press the release button if you are a rear seat passenger who has been left in the car with the engine running, doors all shut, and you need to get out.

Switching the engine off, or opening a door, will release the locked seat back auto matically.

Sounds like perhaps someone has over-ridden the system and locked yours permanently. The trouble is usually that the vacuum pipe has come adrift and the seat wont lock at all. Using wire is a naughty bodge.

I never realised that. That is why this forum is SO valuable. They don't tell you stuff like that when the car is thirteen years old. Thank you.

I'll see if my CD manual has a "map" for the vacuum routing, and check all the pipes to the seat. Where is the reservoir for this? This is the first coupe I have owned, having been a TE man for the last 10 years....

I'll report back, but it will not be for a few weeks yet as the car is being prepped for me.

 

[MotardMan]

I have just read the manual and the only way the seat back can be locked, is if the doors are shut and engine is running and the release button is not pressed. So I reckon the seat has been rigged to stay put as Apial pointed out. I have found the sections in the manual concerning the seat back and the vac circuit diagram too. I'll let you know the result when I have the car here.....

 

[MotardMan]

OK, the bad news is that the passenger side is locked solid, and the drivers side is not locked, even when the engine is running... So we have a vac issue on the drivers side for sure, and a seized mech on the passenger side possibly... At least I have nearly a year to get it fixed, though I am a little concerned about how the car went through its MOT with a seat back that would not lock.......

 

[stever]

I've had this problem on both of my W123 coupes. If you are lucky, it may be that the pipes have become detached and all you have to do is plug them back in (this happened on my previous coupe). If you are unlucky, you will have to remove the seat from the car and replace the vacuum diaphragms. Also check the pipes as these can crack too, especially if the action of the seat tilting forwards over the years has rubbed against them.

 

[MotardMan]

I've had this problem on both of my W123 coupes. If you are lucky, it may be that the pipes have become detached and all you have to do is plug them back in (this happened on my previous coupe). If you are unlucky, you will have to remove the seat from the car and replace the vacuum diaphragms. Also check the pipes as these can crack too, especially if the action of the seat tilting forwards over the years has rubbed against them.

Great tips, and I have the vac hose layout now, so will be checking the hoses this weekend and seeing where we go after that. Thanks very much.

The worrying thing is that the car just passed an MOT with a "floppy" seat back...... I've told the seller about this and asked him to explain how the MOT was obtained with the seat like this...... No reply as yet.

 

[MotardMan]

Update. I managed to get the passenger seat back to fold forward. How? Well, whilst I was upside down in the rear fotwells trying to release the catch on the stuck seat back lock, I noticed the cover trim for the hinge mech was dislodged. It was jamming the return spring for the hook that locks on the pin, thus stopping the hook from retracting fully. I wiggled the trim back into place and "PING!" the hook went back and seat back released.

Now I have two floppy seat backs..

I removed the rear seat cushion on the n/s, and located the vac unit. On my car there is a blue hose to each seat, and single blue hose that runs to the inlet manifold. I poped off th hose from the inlet manifold and there is vac in the line to the splitter. So I know the pipework is good from the splitter, to the inlet manifold. I'm guessing the vac diaphragms are shot in the seats themselves. Anyone have a part number or price for these items?

 

[MotardMan]

Fixed!

Finally got to to reseat (scuse the pun) all the vac lines that feed the seat, and at last the seat backs lock as they should. I opened all the windows so I could lean in from outside the car and check that:

Engine running, doors closed, both seat backs lock. They do.
Engine running, open the door, seat backs unlock. They do.
Engine running, doors closed, press button on seat back, seat backs unlock. They do.
Engine off, seat backs unlock. They do.

Thank goodness for that. It seems there must have been a leak in the pipework at one of the junctions and reseating it with a smear of vaseline on the hose has sealed the leak. Also not helping was the jammed mechanism on the passenger seat hinge next to the centre console.