Unable to fix boot leak

[Rick-sta]

Hi all,

I've had about 5 attempts now to try and fix a boot leak in my dad's 75 saloon and cannot find where the water is leaking through.

The leak keeps dripping down here on the left side of the boot. Was wiped completely dry last night and this is how much water has leaked in over night.





When it first started I couldn't even tell where the leak was coming from. Would dry the whole boot out and then pour loads of water over the whole rear of the car from the rear screen back with the garden hose and buckets for a considerable amount of time and not a single drop of water would leak into the boot. Tried this on a few occasions and nothing would come through. And yet leave it in the rain for a while and you'd get a puddle on the left side.

This car has been riddled with boot leaks since soon after we bought it. It's leaked through the driver's side boot air vent which has been sealed and hasn't leaked since, the driver's side waist trim clips, also been sealed and still fine, rear light seals which were replaced and are definitely now not leaking, the rear windscreen which I sealed about 6 years ago but resealed again over the weekend to be sure the leak wasn't coming through there. When sealing the rear screen I removed the chrome surround trim and applied waterproof sealant thoroughly on and around all the clips along the bottom of the screen.

Yesterday morning on another attempt to find the source of the leak I noticed if I pour water down the left side of the boot with the bootlid open a small amount of water would get past the underside of the boot seal in one small section. So removed the whole boot seal, cleaned it up and applied a water proof silicone to the seal before refitting it.

And yet the leak is still there.

These are the following areas where I'm certain there's no leak:
- both left and right air vents
- both tail lights
- waist trim clips on both sides
- rear windscreen clips
- boot seal

Now over the last 2 days I've noticed that there is leak is coming through the joint in the metal here:



This had been partially sealed before, and I sealed the rest of it a week ago in case the leak was coming from here. Underneath the sealant there's a joint in the metal here which isn't welded together from the factory. I'd suspected the leak had been coming through here as it's directly above where the puddle builds up each time but was dry every time and couldn't get water to leak through there when testing for leaks. But yesterday I noticed it was a bit wet and today I can actually see it dripping from there where it's been raining all night.

Now where would the water be leaking through for it to get here? I've already sealed the joint on the top side (used tiger seal here which seals solid so no water will be getting past that).



As above the windscreen clips have been sealed with a lot of sealant (used selley's storm sealant which is great waterproof stuff I used to seal headlights).

Where could the water be coming from to leak through into the boot there I cannot find it?

Cheers
Rick

[kelvo]

Rik, might be worth checking the seam right in the corner as well and along the wing. I had a similar leak on my ZT, although on the driver's side where the water would run down the wiring loom to the rear lights and drip down behind the sat nav drive (not in it fortunately). I could see cracks in the factory sealer which I suspected as the cause of ingress.

I sealed with brushable seam sealer and painted and touch wood seems to have been OK ever since.

[trikey]

Captain tolleys on the seam that joins the boot lip to the rear quarter Rick, start at the back edge of the screen and finish near the tail light.

[Mike Trident]

Mine has started with a very small leak in exactly the same place but I suspect mine is rear window trims etc

[Rick-sta]

Originally Posted by trikey

Captain tolleys on the seam that joins the boot lip to the rear quarter Rick, start at the back edge of the screen and finish near the tail light.

ah sorry should have mentioned I've sealed all along there already too, right from the tail light to the rear screen. Also removed the boot hinges and sealed around the bolts and refitted as I was getting some water drops on the back end of the bolts inside the boot.

[edwardmk]

The serious water ingress into my V8 saloon drove me nuts for nearly a year. Did everything mentioned in the forums. Huge result with Arctic's tips, but it still leaked. I tried paper, UV dyes, replaced and sealed all the 8 trim clips under the rear window, everything else you've done Rick. When I silicone sealed the entire boot seal and adjusted the compression on the seal with the boot closed, that did the trick for me. With heavy rain the water flow from the roof overwhelms the boot seal unless it's perfect. I ended up having to seal a brand new boot seal, so if yours is old, check no cracks/splits anywhere and the holes are on the inside. Heavy rain would overwhelm a dodgy seam so I'd definitely try Trikey's tip. I have a bottle of Captain Tolley's ready for the next leak, but nothing so far on the V8 lol. I do unfortunately have a small leak in the rear of the tourer with damp carpet on both sides and ending up in the wheel well. That's be my next project when I find time. Good luck. Watching this thread with great interest.

[rab60bit]

Originally Posted by trikey

Captain tolleys on the seam that joins the boot lip to the rear quarter Rick, start at the back edge of the screen and finish near the tail light.

Do we scrape out the old stuff or just seal over after a clean up?
Mine is driving me crazy but I suspect this is the issue. The failed sealing/sealant isn't obvious and I simply cannot see it leaking (other than the pooled water) - the O/S over/near the sat. nav. DVD drive and rear light housing is the worse of the two.

[bl52krz]

Hi Rick. I had a leak from where the nearside rear wing joined the panel that formed the boot by the hinge .I sprayed some wd40 on where the joint is, and it came straight through onto some kitchen towel I had put under the joint. I then got my waxoyle out, and used a brush to force it down into the said join by the boot hinge. Never had anymore trouble with water getting in. Just try it. Costs next to nothing and five minutes of your valuable time.

[ceedy]

I chased a leak right there on and off for years, in the end capt Tolley's all round the near side boot hinge & bolts and it's finally dry.

C

[Canonite]

Ive literally just posted the same thing on my facebook group about this. It is a creeper between the spot welded plates.
Its not a gusher but over time it was sufficient enough to ruin a Mk4 satnav and Harman Kardon amp.