240 General: water leak around bonnet release

[PTJS]

Having suffered from the 'indoor swimming pool' that end up in the rear footwell of my 240GL for some time I have at last made a determined effort to locate the source of the problem. With a watering can armed assistant the water appears to enter the drivers footwell area via the white bonnet release 'trumpet' mechanism where it passes through the bulkhead. I thought it would be easy to unscrew/dismantle it so that I could get some sealant around the fitting before tightening it back up again. Darned if I can fathom how it comes apart, nothing in the Haynes manuals that I have either. Can anyone help?

I have also noticed that the rubber trim that fits to the engine bay bulkhead drainage gutter (under the windscreen end of the bonnet) is not long enough to stop water trickling down at its ends behind the bulkhead lagging and where some corrosion has resulted, probably after years of seepage. Does the rubber trim shrink with age? I will have to remove the bulkhead attachments like wiper motor, fuel filter etc, strip off the bulkhead lagging and see just how bad this is before restoring it. Has anyone else had this problem and is there anything I should look out for when doing this?

[classicracing]

What year is your 240?
There were a number of problem areas with bulkhead / 'A' pillar leakage around 86-87 I will go through it if you are in this period
Let me know
Richard

[PTJS]

Its a 1988 240GL saloon.

[Clifford Pope]

You are right about A-pillar leakage. I've caught the rust in my 89 model just in time. The driver's door post on an 86 I was given and dismantled had completely rotted, and the door fell off its hinges. There was no outward sign of anything wrong, until then.

[PTJS]

Thanks Clifford. How did you deal with the rust on your 89 model and how can I check if my car also has this problem?

[Clifford Pope]

Well, it hadn't actually rusted to the point of going through, just lots of very flaky surface rust.
Take off the side panel, rip off any sticky paper, also lift the carpet and pull out all the platic plugs. Then it's a matter of sucking out all the debris and clearing off all loose rust, and seeing what's left! Also clear out the drain slots in the cill. Try pouring water over the windscreen. Then try pouring it down the grill on the bonnet. The water is supposed to run down the passage between the bits of bulkhead, and emerge from the slot between the front wing and the rest of the cill. If any of the plugs are missing, or vital bits of channel rusted away, it can get into the cill or inside the car. That too is a danger point, because it can lie unnoticed under the carpet, under the metal channel for the wiring to the rear. It then quietly rots through into the front outrigger, which again may have blocked drainage.
It's a curious mixture of sections where the water is supposed to go, and drain through, and bits where it can go if plugs are missing, holes rusted through, or drainage exits blocked.
But the hose test should reveal all.
I've never had to investigate the possibilities of leaks from inside the bonnet, but I imagine the same factors apply - water has to go somewhere.

[PTJS]

Thanks Clifford.

A few mpnths ago I stripped the inside of the car out to waxoyl the interior of the cills and anywhere else I could get at from within the passenger compartment. The cills were all clean inside apart from light superficial rust from what I could see through the big access holes. I didn't however remove the plastic side panels which I presume are those next to the front door pillars in the drivers and front passengers footwells so I'll do this and see what is revealed.

In the meantime can you help with regard to how to dismantle the bonnet release trumpet from the bulkhead so i can seal the leak from around it. I can't quite fathom it and I've a funny feeling it could be one of those five minute jobs that could develope into 5 hours without a bit of research!

Phil

[Clifford Pope]

I confess I've never actually studied it. Obviously the cable has to go through some kind of hole, but I've never thought about it as a potential water leak.

[Alec Dawe]

Originally Posted by PTJS

I have also noticed that the rubber trim that fits to the engine bay bulkhead drainage gutter (under the windscreen end of the bonnet) is not long enough to stop water trickling down at its ends behind the bulkhead lagging and where some corrosion has resulted, probably after years of seepage. Does the rubber trim shrink with age? I will have to remove the bulkhead attachments like wiper motor, fuel filter etc, strip off the bulkhead lagging and see just how bad this is before restoring it. Has anyone else had this problem and is there anything I should look out for when doing this?

Just been to look at mine, Nasty foam padding behind the rubber facing nicely soaked with water after two days of rain!
Just exactly what is this bit of foam and rubber supposed to do. It can't be heat insulation, because the rest of the firewall/bulkhead under this level is completely bare, just painted metal, and that part is a lot closer to the exhaust and engine heat than the top strip. All the rubber top layer on mine is disintigrating, one touch and it cracks to bits.
I'm seriously considering removing the lot, and just cleaning up and painting the area between the bonnet line and the weld with something like a hammerite heat resistant paint. Regarding the 'shortness' of the rubber seal above, I think the little gap at the ends could be bridged with a little silicon seal bead, to encourage any water to run down the proper channels onto the bulkhead, and out. The rubber seal itself seems at one time to have been bonded in place, as well as spring gripped, perhaps a little more silicon here to re-attach it, and prevent more water lying.
Had a look at the bonnet release cable run, MMMMMMMMMMMMMMM it goes behind the top suspension tower, in the double skin space; now that really looks like fun to remove, especially as the hole through the bulkhead is also inside another double skin section.
I think this could be a case of VERY, VERY carefully, and attach bits of string to everything to give you a chance of getting them back where they came from!
I have an old green Haynes manual, and have just hunted through it, and I have found the following instructions on how to remove the bonnet release cable:-
1.Remove the grille, and then unhook the bonnet release cable from the bonnet lock mechanism.
2. Remove the cable clips seccuring the cable to the inner wing.
3. From Inside the vehicle, grasp the release handle sleeve, and pull the complete assembly into the interior of the vehicle.
4. Refit, or fit a new cable in the reverse order, sealing the hole in the engine bulkhead where the cable passes through with suitable sealant.

Sounds simple doesn't it!!! I'd still be inclined to tie string to the bonnet lock end of the whole thing to assist in getting it all back into place; but it does look as if there is a water entry possibility there.

Alec

[classicracing]

Sorry not to have responded before, been away second half of the week.

Your 88 240 is right in the middle of the problem I remember well. here goes

The BLUE TOP bulletin 8/81/104 dated April 87 refers to bulkhead leakage. It's a 5 pager and covers testing procedures and rectification. My 28.8meg telephone line would take a long time to send this, but if there is a central upload place I'll have a go, if not I can always copy it and send it via Postman Pat

Basically the problem arose because the Torslanda factory was still building 240's years after they were due to be replaced (850).
The press moulds for stamping out the body panels were worn down and the pressed shapes became smaller and smaller (believe me this happened) around the bulkhead the panels should touch together and allow a small bead of sealant to waterproof.
With worn presses making the panels smaller the gaps got bigger and the factory poured more and more sealant into the joints to seal them and guess what, they didn't do enough and the leaks started.
This didn't show up because of the alloy plate over the floor between the inner sill and the floor in the front and good old rubber snow trays in the rear footwells covering up the soaked carpet

The fix is a B*****d to do but is the only sure cure. you must follow the test procedure to find out if this is the problem you have got and not another such as hinge box leaks or grommet leaks

If you really want to do this let me know where to post the bulletin (Clifford?)

Just to refresh the memory Green top bulletins are direct from the quality dept in the factory, Blue tops are UK Market written by the UK technical support dept.

(Ask me how I know that if you want long stories)

Richard Clark

BTW the presses were replaced 89 ish when the decision was made to continue 240 until the customers stopped asking to buy them (92)