5 replies to this topic

[goat64]

Recent monsoon, ankle deep puddles everywhere.

My 850 now has a new unexpected feature: passenger foot spa.

 

Floor pan was a bit rusty (from prev leaky radiator drip-feeding it with rust converter: i.e. coolant to convert metal into rust!), but since repaired / treated to be sound enough. I don't think the floor is leaking. It's certainly not leaking out from the footwell paddling pool.

 

When mopping out footwell, noticed drip maks down below ddoor trim inside.

 

Last time I had inner door trim off, I rememebr noticing some perished brittle grey tape over all teh gaps in the inner skin. Being a novice (idiot), didn't think more about it.

 

Putting 2 and 2 together, combination of monsoon and perihed grey tape = footspa.

 

Planning to investigate this weekend, with a view to replacing presumed 50 year old tape.

 

Only found  1 post on here about this, and not a lot online. I suspect because it's obvious / too basic for most.

 

Pleasse advise:

Is it just a question of covering over the gaps in teh inner panel with new duct tape or similar? 

Is there anything else I should be checking for whilst I'm ddismantling stuff?

Will probably spray remnants of can of S50 wax inside when investogating.

Anything else to do whilst I'm in there?

 

Thanks

[mab01uk]

I would use something like waterproof 3M Duct tape for the inner panel holes.

 

Also check all the drainage holes in the bottom of the doors are clear.

 

Similar leaks in my Minis have usually been water creeping past the rubber door seals and then running down the inner sills into the foot wells and under the carpet.

 

Minispares sell these plastic membranes for door cards to prevent the door cards from warping due to damp:-

https://www.minispar...tic-membrane-pr

 

[goat64]

Door drainage holes are on my regular check list due to mini door rust trap there.

I will invest in some proper waterproof tape as you suggest. My cheap roll of "waterproof" tape from Wilko (remember them) has probably lost what ever adhesive qualities it once had.

 

I will take a look at the platic skin thing too, but that is to protect the hardboard back of the door cards, rather than stopping water ingress from door panel, right?

 

I had wondered about the door frame trim at lower edge, as it is the original and I'm sure less rubbery than they were 50 yrs ago. They look structurally in goo dnick: no cracks or splits that I can see..

Loathed to replace if possible, as I gather there are people out there that like things kept original.  Oh and also I am skint after paying top dollar for new sill replacement!

 

If the tape trick doesn't work , I will investgate floor lip trim further.

 

Out of interest, is the sticky tape thing standard in minis / all coars to cover up access holes in inner door skin?  If so, is that a bit of (another) design fault?  Surely there must be some way of selaing the inner skin better than sticky tape, if water is expected to get into that space routinely?

 

Thanks

[mab01uk]

The sticky tape thing was the standard production method for sealing the access holes on Mk3 onwards Minis with winding windows and does the job ok. Remember Minis, like most cars designed in the 1950/60's were only designed to last 8 to 10 years max back in the day before being scrapped, so using the tape was not really a design fault needing to last 50+ years...

 

If you do need new door seals in the future 'Phoenix Trim' below do various types for Minis:-

https://phoenixtrim....-seals-72-c.asp

 

Yes, the Minispares plastic membrane skin is to protect the hardboard back of the door cards from damp/condensation, rather than stopping water ingress from the door panel.

Edited by mab01uk, 21 October 2025 - 04:50 PM.

[sonikk4]

+1 for the drain holes. If they are blocked and you do get a lot of water it will try and find an alternative route out. Damaged membrane will not help or its not sealed correctly.

 

However if you are getting that much water in then i would be checking the window seal to make sure thats good or if not the door check strap seal as well.

[goat64]

OUTCOME:

Did the duct tape thing: Fixed !

 

Drainage holes all clear. I have used a panel spray wax with a long lance up inside and made sure drain holes still clear after.

 

Tip: make sure you have some spare new panel clips before you start easing off the inner card. Several of my 50 year old clips were so brittle they crumbled when gently trying to pop out.