Leaky back end.

[samuel_m]

After a bit of investigation and pulling out the carpets, it turns out my leak is coming from the sealing frame (No. 13 in the diagram below – 51718398104). The water is either getting in through the frame itself, which is cracked, or finding its way past the perished/dripping butyl that seals the frame to the bodywork and roof.

From what I’ve seen, this seems to be a fairly common point of failure on the Z3, particularly where the frame itself snaps. In my case, it’s cracked in one place only, fortunately right down the middle.

I’ve been following this useful Google Doc that walks through the process:

Z3 Sealing Frame Replacement.pdf

drive.google.com

I just wanted to update the forum and let people know what I’m up to. I’ll be cleaning all the old butyl off tomorrow. It definitely looks like someone’s attempted a repair before and done a not-so-brilliant job.

Before I refit everything, I was wondering if anyone has any tips or recommendations for reinforcing the plastic frame to prevent it cracking again?

 

[samuel_m]

Made some slow progress with butyl removal but it’s really stubborn stuff.

I think someone has used little skinny strips of foam at some point.

 

[ExMX5owner]

I found that the butyl came off really quite easy on a warm day, if you use the ball of butyl you have already is used to peel the rest off...

Foam strip, well I dont know.. Cant say I enjoyed the job though...

 

[Eddie Zedder]

The foam strip fits above the bitumen tape between the body work and the plastic bow (gasket). Part no 51452353024.

 

[samuel_m]

The foam strip fits above the bitumen tape between the body work and the plastic bow (gasket). Part no 51452353024.

Thanks Eddie, I hadn’t appreciated that - I’d thought it was a later addition.

I think it’s worth me picking up some foam strip then.

 

[samuel_m]

I found that the butyl came off really quite easy on a warm day, if you use the ball of butyl you have already is used to peel the rest off...

Foam strip, well I dont know.. Cant say I enjoyed the job though...

Good idea, I’ll try warming it up with a hair dryer, see if it makes any difference. It really of of those necessary but painstaking jobs…

 

[Mazza]

one bit of kit I have used to repair various plastic parts ( bumpers , rear turret tops, wheel arch liners, plus other parts) is an electric staple gun.

it heats up the staple ( various types supplied with it ) and push the staple into the plastic. really easy to use and then cut off the surplus that stick out with flush side cutters.

Just hold the split tight and put a staple across it . If its a long split just space staples along it.

Turret lug snapped off , so bit of super glue in the joint and 3 staples to strengthen it

Bumper Split

 

[samuel_m]

one bit of kit I have used to repair various plastic parts ( bumpers , rear turret tops, wheel arch liners, plus other parts) is an electric staple gun.

it heats up the staple ( various types supplied with it ) and push the staple into the plastic. really easy to use and then cut off the surplus that stick out with flush side cutters.

Just hold the split tight and put a staple across it . If its a long split just space staples along it.
View attachment 353759

Turret lug snapped off , so bit of super glue in the joint and 3 staples to strengthen it
View attachment 353761
Bumper Split
View attachment 353771

brilliant idea I’ve just ordered one. Thank you.

 

[Mazza]

Just a tip … read the instructions ref how long you heat it for etc,
push them in on the back face and don’t go to deep ( about half way !!)

 

[Althulas]

White spirits is also good for cleaning up the goo. I used a foam strip and two rows of butyl. I’m sure Jack Trimmers in the future will be thanking me for that but at least it’s water tight.

 

[Gatsoburner]

Great info with pictures, makes understanding easier. Just a question, the water into the boot, was this running down the back bulkhead in the boot from the fabric roof ?..ive a feeling my cars suffering similar

 

[samuel_m]

Great info with pictures, makes understanding easier. Just a question, the water into the boot, was this running down the back bulkhead in the boot from the fabric roof ?..ive a feeling my cars suffering similar

It’s interesting you say that. My boot felt/material on the back wall, was wet a couple of times a while back and seemed to be related to me pouring water on roof/back window, but it’s not happens again since, despite not having fixed anything… I may rip out the boot lining and do some water tests. If I do I’ll post pictures .

 

[Gatsoburner]

Sounds similar. When I took the carpet out revealing the metal bulkhead water was sat on the top lip at the join, hard to get at so I blasted it dry with a hairdryer. Its right below where id guess the join you've repaired is.
Something ill look at in spring time I think.

Bizzarly I knocked out the boot light, blew the fuse but thought ill sort it another day.

Carried on to the water inside the RNS light and took it out, the water was getting in through the foam around the 5 bulb points, 1 more than others.

All put back but frustrating the obligatory rear light would work, assuming id knocked or damaged it taking out the light so again I stripped it out, tested, no joy .

Anyway, a check on the fuse system diagram only showed the boot light is fused with the RNS light... AHAAAA..!!!

Fuse in, all sorted. 2hrs fixed by 1 minute..DOH !!

 

[samuel_m]

Update:

After a lot of scraping and WD40, the sealing frame is clean. I can now see the cracks clearly. One right down the middle and the second a horizontal crack.

Next: I’ll hot staple it all together, melt the plastic over the cracks a little and then coat the cracks with JB plastic bonder.

 

[Althulas]

If it doesn’t work out I have a spare in my loft in a lot better condition, not perfect but serviceable with very minor attention.

 

[samuel_m]

If it doesn’t work out I have a spare in my loft in a lot better condition, not perfect but serviceable with very minor attention.

Wow, brilliant. I’ll certainly keep that in mind

 

[samuel_m]

I’m missing one of these little washers, I can’t see a part number on RealOEM…

seems to be made up of a metal washer/spacer and a plastic clip on part at the back.

I wonder if I can just do without one.

 

[samuel_m]

Crisis averted. I found it, rattling around in the car.

 

[samuel_m]

Update: welded/stapled and ready to coat in gloop.

(washer is only there to see if it still fits)

 

[Mazza]

if you need any of the washers I have loads of spares …
just PM to let me know and I will send some of them in the post.