Rubber seals

[2800csm5]

Does anyone have a good source for reproducing the rubber seals
that wont deteriorate after six months.???

(1) The rubber inserts on the front vertical edge of the rear
windows. The ones that slides into the chrome strip.

(2) The U shaped seal for the rear of the hood. It fits across
the water channel below the windshield.

I have two fully restored coupes and both these rubber seals
have totally deteriorated in less than six months. Both were
treated with BMW rubber and vinyl with UV protection cleaner
at least once per month.

 

[pmansson]

I have never had an issue with the one in front of the windscreen, sealing off the vent intake area and dampening the bonnet/hood. I have simply not treated it with anything.

The vertical one on the rear quarterlight is different. Firstly I try to remember to lower the door windows when not using the car for a while, just to avoid the pressure from the door window against the rubber seal. Depending on the alignment, this pressure varies. I have one car where the door´s glass hardly touches the seal, and others where the pressure on the seal really deforms it. These alignments are not always easy to set in a "normal" position!
This vertical seal also has the sideways motion of moving glass to cope with. Hence we don´t want it like new tyre rubber. Try some white paraffin or Turtle Wax "Nano Powertech" Bumper and Tyre shine. It leaves the seals protected?!?! but certainly a little "slippery" to facilitate the door window moving up and down against it.

While on the subject: As I get in the car, I lower the window about 25% (or all the way if I will drive with window down), then shut the door, then raise the window. It just feels better for all the fragile parts. With the window down completely, I can close the door with my right hand, near to the rear edge of the door. This avoids any pressure on the inside door mounted arm rest.

 

[2800csm5]

That's strange, I know of at least four other coupes that the
one in front of the window has deteriorated. Including mine,
that makes six.

Maximilian and La Jolla Independent sells replacement seals
for $85.00, but I'm reluctant to purchase a part for that price
and have it fall apart in six to eight months.

What I do with the rear window seal is, insert a rubber vacuum
hose down the full length of the seal. That prevents the seal from
being pressed flat or twisted when the front window is moved up or
down.

 

[blumax]

Seal problems

As a 36 year owner of several Coupes--one nearing 37 years--the BLUMAX since Feb 1972--have never had the experience you describe--large seal at base of WS has now been in place for several years and is like new--the side window vertical seals uusually last for 4-6 years depending on how much window action they experience--and not expensive.

seems somewhat odd that an $85 price tag for a large seal at WS base would be an obstacle for an owner of multiple coupes who must have MANY TIMES THAT AMOUNT in engine and transmission upgrades alone apart from costs of restoration.

Are all your seals original BMW parts--or other?

 

[Ed G]

Like many plastics, rubber can be negatively affected by cleaning agents and so called preserving compounds etc... I'd be careful about trying to use ANY chemicals to treat your seals other than an occasional cleaning with very mild detergent. Before I decided to "treat" the seals, I'd make sure that the agents were 100% compatible.