Leaky Interior 280e W114

[foursail53]

Hi there, I've owned my 280E 1973 for about 3 months now, and I love it. However it is my main car and it has sprung a leak from the heater air intake. With the onset of autumn/winter, I am keen to get it plugged but I am finding it difficult...! Help!

The leak is comming from the bonnet/heater air vent. I think there are a few rust holes near the actual drainage holes. The drain does work as after pouring water down there, most of it ends up in the ground where it should be. However, I get trickles comming down from behind the heater system in the cabin. It then collects in the footwell on the drivers side. I removed the centre consul with the intention of removing the heater but it looks more difficult than anticipated.

Has anyone had this problem and how did you solve it?
Does the heater unit need to be removed or can I get to the draininge vent another way?

Further more; after a heavy storm last night, with the air heater ducts (leading to the rear seats for foot warming) removed, water was also dripping from the air outlets on the heater unit and collecting onto the footwells on both sides. Is this normal? was it a result of an overflow after the heavy rain?

Thanks for reading
:mrgreen:

 

[TimN]

It's been a long time since I took one of those BEHR heater units out but I recall that after removing the centre consul, a few retaining screws and releasing a host of cables and hoses that the unit will rotate out. It's a job for a small fellow that doesn't mind working upside down for the day.

I suspect that you will find a number of rust holes which will need to be patched.

You could get better access by removing the grill panel from outside. If I recall correctly remove the winscreen wiper arms. Open the bonnet and you will see a row of clips. Use a small nail and then after blunting the end drive the peg in the middle of the clip into the void behind. Then prize out the clip and work the grill panel out.

 

[foursail53]

Hi TimN, thanks for the quick reply, and advice.

I had managed to locate the holes by taking off the grill panel as suggested. After trying 'plumbers mate' to see if I could block them, I still get a leak. (this may be beacuse plumbers mate might not agree with the waxoyl I put down there!) I am sure you'll agree that there is not too much access to the drainage holes.

Most of the access from the grill panel is obstructed by the blower-fan and its cowling/drainage gutter. Do you know if it is possible to remove the fan and cowling to get better access to those darn holes!?

As you might be able to tell I am trying to avoid removing the heater itself. I shall take a closer look though. I am 6ft 3, so upside-down footwell acrobatics are a little harder for me!

Thanks in advance!

 

[TimN]

I got rid of the 114 many years ago but still bits and pieces remain in the garage to this day. One of those pieces was the heater unit. I recall taking it out on a number of occaisions. It comes in two halves so that they can be separated to replace the heater matrix. The two halves are held together with strips of steel in a C shape. It is not possible to split the halves befor removing the whole unit as some of the clips are round the back.

It takes seconds to remove the front seats so I suggest that might be your best option to gain the most comfortable access.

 

[foursail53]

Hello Timn

Again thanks for the quick response! Yes I attempted to split the heater as you say the other day, and it woudln't budge. Not having the workshop manual for European spec cars (I have the USA manual with A/C only!!) means that this kind of info is greatly appreciated!

I will defenatly take another look at the heater with the useful advice you have given. I will also take you up on removing the seats (I actually replaced the drivers seat for a passengers side seat from a W123 I found at a scrappie in Norway - needed a headrest and a seat with no slits/damage!) So it should be straight forward enough to get 'em out again.

Thanks again! - I'll let you know how it goes!

FS

 

[foursail53]

Right! Seats came out, then I disconnected the hoses to the heater unit.
After removing the various nuts and bolts and cables that hold the heater in place, I began to tackle removing it.

I wrestled with it for 4-5 hours and I got as far as dropping it a few inches from it's normal position. There was always too little space to manoever the d*mn thing! Something was in the way which ever you tried to move it.
In the end we managed to move it enought to see some of the rust holes where water was seeping in. However there wasn't enough light or space get a good look or do anything about it.

Despite trying for such a long time and with the help of my dear ol' Dad (we are both competant with cars having restored an MGB and Spitfire in the past) we could not see any other way to get at the heater matrix other than REMOVING THE DASHBOARD!? Hopefully there is something obvious that we have missed?

Any further information or data-sheets/manuals on heater matrix removal would be great appreciated!

'Oh.... it's all part of the fun!'

Thanks in advance!

FS

P.S. thanks for the advice so far! I don't have a workshop manual!

 

[guydewdney]

nope - its a dashboard out job im afraid.

I have the genuine MB manuals for the 114 and the M110 engine - I can lend them to you if you want. They are about 3" thick each (4 manuals total)... I spend a lot of time in wokingham, you could pick them up from me, yately isnt that far.

Or buy yourself a set from mercman in southampton - 50 quid iirc.

 

[TimN]

Dashboard does not have to come out. From what I remember there is a central support bar to the dash board to remove. There are self tapping fixings to either side of the prop sharft tunnel. There are the ducts to the left and right vents and there are hoses and cables to remove. As far as I recall the top ducts just slot into the windscreen demist vents and are not fixed to them. To increase your chances as I expect it is the flow and return pipes on the heater matrix which are causing your problem, remove the grommet from inside the engine bay and have someone push. The sound proffing on the propshaft tunnel can also cause a problem.

I have just remembered that the central fresh air grill has a rubber sleave which joins the heater unit. The flap which controls fresh air will be connected to the slide via a rod which will have to be released or it will get bent. It is probably a ball and socket arrangement reached through the grill with an appropriate sized screwdriver.

It will come out eventually like a 12 lbs natural birth.

 

[guydewdney]

heater box removal:-

drain cooling system and disconnect hoses at rear bulkhead in engine compartment. remove heater duct to rar compartment and take out the right defroster nozzle (this is for a LHD car, so they may mean RHS defroster nozzle on UK cars...Im assuming you swap all lefts for rights in the following description)

remove the outer cover from under the instrument panel. remove the two nuts that hold the supporting bracket (either side of the box, near the front, slotted holes) and take out the screw that secures the bracket to the transmission tunnel. Reach throughthe glove box apeture and free off the rubber cuff from the casing

detatch ball joint on the flap linkage of the centre air duct. remove leftside fixingnut of the instrument panel from the top of the dash. free the bowden cables from the rhs of the heater box

hold instrument panel up by lifting the lhs nozzle and ease heater box out of the rubber gromments in the scuttle and remove to the right



copied from an 'autobooks' manual for a "1968-72 mercedes 250"


hth

guy

 

[foursail53]

Thankyou chaps for your prompt and detailed replies, I will give it another shot this weekend! (and hopefully for the final time!) I am determined not to be beaten on this!
I shall let you know how I get on.

Thanks again

FS

 

[foursail53]

drumroll please!

Hi, OK... heater is out! Hurrah!

The process:
The seats came out again, and many nuts, bolts, a glove box, centre console, and heater hoses etc.
I started to follow the instructions recieved from Guy and Tim and clear the unit from all it's connectios to ducts etc. However after trying the ways suggested it still wouldn't budge! Arrgh! (this was de to the throttle bar behind the heater was obstructing the movement needed, aswell as the unit just being too large for escape).

In the end, I decided and managed to prise-off the 'c'-clip at the rear of the heater (there is only one!) and remove the lower section exposing the matrix. This gave me more room to angle the unit up and down and eventually (with the help of a patient father) work it free.

With the heater unit removed, I was able to get a clear view of the leak. There is indeed an area of rot (about 2 inches high and 6-8 inces wide) where water could come from the panel grill drainage area. This rusty area was also covered by the throttle bar so this had to be removed in order to have a good look.
It is going to be a welding job (beyond my humble skill) so the car is booked to go into a repair centre on monday for patching. Once this area has been sealed I should have no more leaks and the process will be to reverse the efforts of extracing the unit!! - *takes deep breath*

I also flushed my matrix, cleaned all the ducts and oiled my heater fan. I then waxoyled the whole area!!! - I love that car way too much!

As an extra note: I also found that inside the grill panel drainage area there is rust in the section that holds one of the throttle linkage brackets (The bracket is in the engine compartment). As this is able to move (...it should stay still!) the throttle linkages are not so effective, thus the car is not very responsive! Again I hope that the nice chap welding my car on monday can attend to this matter.

Again, I wish to thank Guy and Tim for all their invaluable knowledge and help in this matter!

FS