There's nothing more annoying than a rainwater leak into a car - damp carpets and steamed-up windows.

You can take each boot side-trim out if you wish, but you can't really get at anything due to the double-skinned metal panels that make up the rear corners.

But it does make it easier to see any water coming in, rather than waiting for the water to appear out from under the side-trims.

So what's the answer? I searched on the interweb and various solutions are on offer, but I thought I'd let you know what worked for me.

1) rear light cluster gaskets.

well it was very clear that a previous owner had tried to seal the old gaskets up, and had probably made them worse.  They were not saveable, but fortunately Ford sell them for about 13 GBP per pair, so it's worth doing this anyway if yours are looking tired or twisted in any way.  Make sure they seat flat, and hold the light assembly flat against the car with one hand whilst tightening the inside plastic holder with the other.

Then try the watering-can test on top of the roof rear corners and into the rear light cluster edges - nope, water still floods in.

2) panel joints at the top corners where the rear panel meets the side panels

it does look like there are gaps here, half-filled with some kind of putty, added into the joint at the factory?  Well I also pulled off the boot aperture rubber oval seal, and this panel join also has putty have added - I cleaned everything off, with a dab of petrol or WD-40 - or whatever solvent.  Once clean and dry, I used a high-modulus neutral cure silicone sealant, one specifically for high movement areas and between painted metal - they use them in the building industry, and are cheap enough from Travis Perkins or wherever.  I've used Dow Corning 791 on another car with great success, so I chose it again.

It takes a bit of skill not to make a mess, but if you've ever done bathroom sealant jobs then you can do this.  Just do it quickly enough so that it doesn't start to skin before you've pressed it in enough, and wipe excess off 'away' from the joint.

You are advised to leave DC-791 to cure without using the car for 1 or 2 days, so plan for that - otherwise using the car will cause the sealant to separate if it's not completely 'set'.

Very pleased with the result, I tried the watering-can test on top of the roof rear corners and into the rear light cluster edges - nope, water still floods in.

3) panel joints at the top corners where the roof panel meets the side panels

you have to remove the plastic roof gutter 'trims that run from front to rear of the car - they are only held on with double-sided sticky tape.

Obtain a plastic bike 'tyre lever' as these are useful for many other trim-removal tasks if you don't already have one for your bike.  Start near the front and lever it up enough to get your fingers under, and it just comes away.

It's up to you how clean you want to make this channel, but 10 minutes each side of rubbing the tape-residue with your fingers will remove it.  Then you can see it's an odd solution, of some kind of 'tape' the full length and width of the channel, sealed along the edges and then painted over.

BUT - look at the end nearest the boot, and on mine, the tape edge had masses of cracks for the final six-inches - it seems the panel-to-panel-shape here has a different level from the rest of the roof-side joint, and the factory solution isn't good enough.

Once clean, run a bead of your chosen sealant down each side of the channel, and smooth it into place with your finger.  This is much easier than the boot-joint step 2) above.

Just make sure at the boot end you have enough sealant to flatten the gap - on mine it was 3 to 4 mm gap at the end - I filled this.

JUST TO BE CLEAR - you are not filling the channel with sealant. I chose to seal the channel sides from front to rear, but it's only the rear six inches where there's a dip on one side that needs filling. 

You are advised to leave this to cure without using the car for longer, nearer 2 days, so plan for that - otherwise using the car will cause the sealant to separate if it's not completely 'set'.

Very pleased with the result, I tried the watering-can test on top of the roof rear corners and into the rear light cluster edges - no water.  I've been out in the downpours of today, and car-moving or car-parked, no water.

 

 

 

how do you insert photos into text?

Anyway - this is the channel once exposed - look at the area marked - it doesn't show on the photos, but this has cracks in it and it's the low point in the channel.

It only has this uneven and deeper section in the final six inches of the channel

You need to at least fill this deeper section - and I chose to run a bead down both sides, front to rear.

 

...sorry this photo is the other way around - but basically the whole channel base is now flat and sealed.

When I am sure it's 100% sealed, I'll put the gutter trims back.

Did this work for you? I'm having the same issues

I did say so in the text above... but yes, there is no water in the boot (or anywhere else where it shouldn't) a year later, and the car lives (usually) outside.

On 2/19/2022 at 8:08 PM, orangecurry said:

There's nothing more annoying than a rainwater leak into a car - damp carpets and steamed-up windows.

You can take each boot side-trim out if you wish, but you can't really get at anything due to the double-skinned metal panels that make up the rear corners.

But it does make it easier to see any water coming in, rather than waiting for the water to appear out from under the side-trims.

So what's the answer? I searched on the interweb and various solutions are on offer, but I thought I'd let you know what worked for me.

1) rear light cluster gaskets.

well it was very clear that a previous owner had tried to seal the old gaskets up, and had probably made them worse.  They were not saveable, but fortunately Ford sell them for about 13 GBP per pair, so it's worth doing this anyway if yours are looking tired or twisted in any way.  Make sure they seat flat, and hold the light assembly flat against the car with one hand whilst tightening the inside plastic holder with the other.

Then try the watering-can test on top of the roof rear corners and into the rear light cluster edges - nope, water still floods in.

2) panel joints at the top corners where the rear panel meets the side panels

it does look like there are gaps here, half-filled with some kind of putty, added into the joint at the factory?  Well I also pulled off the boot aperture rubber oval seal, and this panel join also has putty have added - I cleaned everything off, with a dab of petrol or WD-40 - or whatever solvent.  Once clean and dry, I used a high-modulus neutral cure silicone sealant, one specifically for high movement areas and between painted metal - they use them in the building industry, and are cheap enough from Travis Perkins or wherever.  I've used Dow Corning 791 on another car with great success, so I chose it again.

It takes a bit of skill not to make a mess, but if you've ever done bathroom sealant jobs then you can do this.  Just do it quickly enough so that it doesn't start to skin before you've pressed it in enough, and wipe excess off 'away' from the joint.

You are advised to leave DC-791 to cure without using the car for 1 or 2 days, so plan for that - otherwise using the car will cause the sealant to separate if it's not completely 'set'.

Very pleased with the result, I tried the watering-can test on top of the roof rear corners and into the rear light cluster edges - nope, water still floods in.

3) panel joints at the top corners where the roof panel meets the side panels

you have to remove the plastic roof gutter 'trims that run from front to rear of the car - they are only held on with double-sided sticky tape.

Obtain a plastic bike 'tyre lever' as these are useful for many other trim-removal tasks if you don't already have one for your bike.  Start near the front and lever it up enough to get your fingers under, and it just comes away.

It's up to you how clean you want to make this channel, but 10 minutes each side of rubbing the tape-residue with your fingers will remove it.  Then you can see it's an odd solution, of some kind of 'tape' the full length and width of the channel, sealed along the edges and then painted over.

BUT - look at the end nearest the boot, and on mine, the tape edge had masses of cracks for the final six-inches - it seems the panel-to-panel-shape here has a different level from the rest of the roof-side joint, and the factory solution isn't good enough.

Once clean, run a bead of your chosen sealant down each side of the channel, and smooth it into place with your finger.  This is much easier than the boot-joint step 2) above.

Just make sure at the boot end you have enough sealant to flatten the gap - on mine it was 3 to 4 mm gap at the end - I filled this.

JUST TO BE CLEAR - you are not filling the channel with sealant. I chose to seal the channel sides from front to rear, but it's only the rear six inches where there's a dip on one side that needs filling. 

You are advised to leave this to cure without using the car for longer, nearer 2 days, so plan for that - otherwise using the car will cause the sealant to separate if it's not completely 'set'.

Very pleased with the result, I tried the watering-can test on top of the roof rear corners and into the rear light cluster edges - no water.  I've been out in the downpours of today, and car-moving or car-parked, no water.

 

 

 

Thanks for the info, much appreciated....will give it a go!

You are welcome.  I've been working on my own cars for over 40 years, but this job is *really* easy as you have full access to the problem area - it's a simple channel on the outside of the car.

But I would look at your light-cluster seals first as above.  It might be that, and that's an even easier job to replace (once you can find and undo the plastic nut on the inside).

... and still no water ingress 2 years later.

Hi OC 

very useful info. I’m about to do this . Have sealed all the potential other areas behind bumper. Wanted to ask, what did you use to reattach the gutter trims. 
regards

Kev

Haven't gotten around to it yet 🤣 but depending on if I feel the need to remove again in the future, as Ford only used double-sided tape, either the same, or simply more silicone sealant.  I'm sure both would work well.

HHi OC 

very useful info. I’m about to do this . Have sealed all the potential other areas behind bumper. Wanted to ask, what did you use to reattach the gutter trims. 
regards

Kev

Hi 
have heard about 3M double sided tape. But not sure how good it is. 

Do you think Tiger seal would work well instead of silicone or is the brush on sealer better. 
 

 

No idea sorry - proper building-construction silicone for a few quid seems a no-brainer to me.  You do need a cartridge-gun, but if you don't have one now, you will need one in the future 🙂

Tigerseal is a very strong adhesive.  If you don't get it perfectly sealed the first time, it'll be a real pain to try and remove.