Possible Mk3 Boot Leak?

[mougly]

With this drain, the little vent become useless or almost.

Nobody really knows how the cavity fills with water : in dynamics, the little vent which is just at the level of the rear bumper undergoes an air pressure which causes the water to flow back and enter : the rear bumper captures the air which rises .

This water is then stored in the cavity on the side from where it cannot leave because there is a rubber cap. The first step is to completely seal the small vent and install the drains.

 

[Schmill]

49 minutes ago, mougly said:

With this drain, the little vent become useless or almost.

Nobody really knows how the cavity fills with water : in dynamics, the little vent which is just at the level of the rear bumper undergoes an air pressure which causes the water to flow back and enter : the rear bumper captures the air which rises .

This water is then stored in the cavity on the side from where it cannot leave because there is a rubber cap. The first step is to completely seal the small vent and install the drains.

 

Interesting, that's not what I found at all. For me it was quite clear that the water flows normal down the body and round the big side vent , you can see the dirty water marks in your photo. What happens often is the water gets past the flexible silicone seal around the edge of the vent and then flows into the body. Removing the vents and the drying and resealing around the edge of the vent solved it for me.

The vents themselves have flaps on them that should stop any air (wet or not) from being pulled into the body cavity.

[Bxzx16v]

As above, I've had no issues since sealing around the vents.

[mougly]

My car is 10 year old and I've never had the carpet problem, only the sunroof seal.

This is not my solution, but Ford's. I show you what was modified to prevent the water to ruin rear boot/carpet.

In this cavity, there is no more foam or sound absorber. I think it is the capilarity that plenish water in the rear carpet.

And imo, Ford's solution is easier.

[Acid House 1988]

On 2/25/2023 at 6:18 PM, Schmill said:

I think the drain tubes are good to stop the car getting completely saturated via the boot, but if water is getting into those side voids near the vents then the wadding etc in there is already soaked.

 

I would add to that in suggesting that the drain tubes might also aid air flow/circulation round those rear cavities where the insulation is so even if the rear of the car is effectively "dry" or "sealed" it's an extra route out for any moisture that may build up for whatever reason.

Just a  thought.

[mougly]

Good video witch explain how to :

 

[alexr12]

I had a boot leak on my Mk2 as well, i think it was caused by the boot seal, maybe this was carried on to the mk3 models. As someone here said, ford tend to maintain a degree of consistency from one model to the next.

On 3/5/2022 at 11:08 AM, deanst said:

Ford always strive to maintain a degree of consistency from one model to the next and carried this feature over so that owners of newer vehicles would feel a bond with the previous well engineered designs 🤣

 

[unofix]

7 minutes ago, alexr12 said:

As someone here said

That was me 👍

On 1/4/2022 at 3:54 PM, unofix said:

Ford always strive to maintain a degree of consistency from one model to the next and carried this feature over so that owners of newer vehicles would feel a bond with the previous well engineered designs 🤣

I'm glad you have found it useful 🤣🤣

[mougly]

My first leak after ten year...

the origin of the leak was the roof of the car : looking at how the roof and side panels were assembled, as well as watching a video on youtube, I applied a transparent sealant to solve the problem (Bostik Purefix).

Ford performs a spot weld and uses mastic to bond/seal the assembly.

But the sealant dries and cracks and the water finally enters.

The sealant was applied under the roof strips and at the rear, as in the video below

 

[Oldson]

I have had my 2013 Focus for three weeks and it has had a boot leak for a long time. Most of the exposed metal work has gone rusty. I took the rear end apart and resealed the four vents as suggested. I must say, the vents did not appear to be lose but I resealed anyway.

Today I decided to remove the bungs at the bottom of the cavity and quite a bit of water came out on both sides.

I am going to check the joints between quarter panel and roof panel on both sides. The sealant looks 'crazed' and I have read that ford seals are cheap and nasty. After that I will check the roof bar fixing and then I'll be stuffed.

Has anybody else found other areas where water gets into the voids behind the rear vents?

[aesmith]

In the "normal" fault of water getting in around those vents, is it rain water when the car is standing, or spray under the car when driving?

Also, what are the vents for in any case, is it outgoing air from the heating and ventilation system? 

[TomsFocus]

12 hours ago, aesmith said:

In the "normal" fault of water getting in around those vents, is it rain water when the car is standing, or spray under the car when driving?

Also, what are the vents for in any case, is it outgoing air from the heating and ventilation system? 

It's rain running down from above while standing or driving.

The vents are there to allow stale air from inside the car to escape (creating a through flow when the front intake is open) and also to stop the windows exploding when you slam a door.

[Oldson]

I’ve now sealed the join between roof and quarter panels and the join lower down the quarter panel. I also removed the roof trims and noticed some cracking around the joint there too. Fingers crossed. 

[coey1]

can you not just remove the vent drain grommets as a permanent solution without going to the expense and trouble of re-sealing the vents ?

[coey1]

oops

[Oldson]

On 10/23/2023 at 5:31 PM, coey1 said:

can you not just remove the vent drain grommets as a permanent solution without going to the expense and trouble of re-sealing the vents ?

There should not be any water getting into the area in the first place. It does not cost a lot of money to reseal the vents. In my case, I don't think they needed resealing but the voids were full of water. Mine must have been leaking for a long time, the seat fixings are rusty and so is the exposed metal on the steering column.

The smell is starting to disappear, I don't think I'm getting water into the car now so I just need to dry everything and get rid of the mouldy smell.

[Hargers]

Hello,

First time poster and also someone who generally does not know much about car maintenance so forgive stupid questions.  Noticed recently that a cloth in a recess in the boot at the rear right, was sodden and that under the boot floor and down the side of the boot towards the rear seats it was wet. Pulling the rear seats up, they were damp underneath.  Cue pulling the car apart to take a look, I stripped back the side panel in the boot and the foam noise damping / insulation was also damp.  After taking a hose pipe to the car for a long time, eventually noticed a leak coming through the area in the photo.  It was a slow drip, not a rush, but water was certainly coming in around the top of the lower of the two holes in the bodywork.  This morning, had a good few hours of rain and keeping an eye on it, can see more water ingress here.  A few well placed cloths are soaking up the water currently, but obviously would like to fix.

I’ve been trying to read up on possible cause and come across this thread on the air vents being full of water and causing ingress when driving, but the leak I’m seeing is whilst the car is stationary so I’m not sure if that is the cause here!  Has anybody experienced this and can pass on any advice or help?  I’m wondering if this maybe a seal or issues with the rear light cluster area?

Many Thanks

[Bxzx16v]

Welcome along to the forum. The boot leak is a common issue on the Focus so well documented on here. First thing I'd try would be to check that the rear light unit fixings are tight, does it feel wet around where they are? The favourite would be the vents behind the back bumper, I've had this on my 2014 Focus and it's not as daunting a job as it sounds to do the repair. If you look under the bumper behind the rear wheels there is a bung which can be removed and if you stick your finger inside you will probably feel very damp sound deadening material and water running out. I've also had water getting through the fixing which holds the spoiler onto the rear hatch but this caused water to drip onto the parcel shelf, after retightening the fixing this stopped and I've now got a nice bone dry Focus.

[Oldson]

My leak seems to have been from the panel joint between roof and rear quarter panel. If you open the tailgate and look in the water channel you will see two joints, one at the top and one lower down. I masked up the area, rubbed down the joint and applied some body sealant. When the tailgate is shut you cant see the new join. My boot is dry and has been for a couple of weeks.

 

Good luck

[Acid House 1988]

On 10/12/2023 at 6:53 PM, Oldson said:

I have had my 2013 Focus for three weeks and it has had a boot leak for a long time. Most of the exposed metal work has gone rusty. I took the rear end apart and resealed the four vents as suggested. I must say, the vents did not appear to be lose but I resealed anyway.

Today I decided to remove the bungs at the bottom of the cavity and quite a bit of water came out on both sides.

I am going to check the joints between quarter panel and roof panel on both sides. The sealant looks 'crazed' and I have read that ford seals are cheap and nasty. After that I will check the roof bar fixing and then I'll be stuffed.

Has anybody else found other areas where water gets into the voids behind the rear vents?

 

Yes, there's another area for water penetration and that is underneath the base of the boot struts. There's a thin grommet under the base which perishes and allows water to seep in via the screw holes and a locating hole in the tailgate.

I've just removed the struts, cleaned the whole area, replaced with new grommets, then sealed up. I've got some pictures of the work involved so I'll post up here as soon as I get a minute.

[Oldson]

On 11/22/2023 at 12:56 PM, Acid House 1988 said:

 

Yes, there's another area for water penetration and that is underneath the base of the boot struts. There's a thin grommet under the base which perishes and allows water to seep in via the screw holes and a locating hole in the tailgate.

I've just removed the struts, cleaned the whole area, replaced with new grommets, then sealed up. I've got some pictures of the work involved so I'll post up here as soon as I get a minute.

👍👍👍

[davidosborne666]

i had the same issue with my mk3. turned out water was getting into the vented box section of the car. if you go under the back of the car you will find a rubber plug that leads into the box section .. i just pulled the plugs and about 6 pints of water came running out i did the same to the opposite side 

[Acid House 1988]

OK, as promised here’s some more detail on what I did with the boot struts plus photos for illustration...

In photo 1 with the boot strut removed you can see the sludge build up as the water runs down the channel on the tailgate.

In photo 2 you can see the sludge replicated on the boot strut. Believe it or not, there is actually a gasket on the bottom of that strut!

In photo 3 you can see I’ve cleaned up the base of the strut and you can now see what’s left of the gasket. I've also cleaned up the area round the fixing on the tailgate area and made sure all that sludge build-up has been completely removed.

I then scraped off the gasket with a sharp chisel and you can see in photo 4 what is left of it – not much! No surprise this is inviting water penetration.

In photo 5 you can see I’ve made a template shape as best I could from the original gasket and then cut a new gasket to size with a
Stanley knife from a small sheet of 1.5mm neoprene which you can pick up very cheaply off eBay.

https://www.ebay.co.uk/itm/261237258709

In photo 6 you can see the gasket in place and the strut re-fixed, I’ve also added a bead of clear sealant to three sides of the strut base so that water is directed away from the strut and towards the drain channel.

Looks nice and neat and that’s another fix ticked off.

[Bea-Norfolk]

Hi I had this on my 2011 focus recently the water in the boot then ended up under the back seats, Took it to local garage and it was a blocked drainage bung in th wheel arch, dried out but leaving a towel under the seat and now all good and no water since un blockin.   i also thought it was seals or boot hatch or lights 

 

[TheWIk]

On 1/4/2024 at 6:49 PM, Bea-Norfolk said:

Hi I had this on my 2011 focus recently the water in the boot then ended up under the back seats, Took it to local garage and it was a blocked drainage bung in th wheel arch, dried out but leaving a towel under the seat and now all good and no water since un blockin.   i also thought it was seals or boot hatch or lights 

 

Where is the drainage bung in the wheel arch? I think this is my issue too....