Question

[yellowperil]

Is it a big deal to remove and re-install rear (windshield) glass on a '95 993? Fairly straight forward? Any do's and don'ts? I have a small spec of rust just under the rubber that I need to fix.

Most windshield shops have little or no experience on rear glass, especially on Porsches, so I'm a bit timid on this repair, as I don't fancy making things worse.

Is it best to get a new rubber seal?

Thanks for your help!

Lower right bottom side.

[tirwin]

I can't speak to the 993 but on my '83 SC pulling that window is not for the faint of heart. I happened to find a local 'old school' glass guy that was able to do mine. I tell people all the time to not make the mistake I did. I was in a hurry to get the job done and couldn't find a 'formed' seal like the OEM Porsche ones. Most of the aftermarket ones don't fit properly in the corners and will result in the same problem you are trying to fix.

When I say formed, imagine you open the package on the Porsche seal. It will be shaped like a rectangle. When you open the aftermarket seals, they come out of the package shaped like a circle. What this means in when the aftermarket seal turns the corner, it bunches up and has a poor fit. I hoped I explained this in a way that makes sense.

[yellowperil]

Originally Posted by tirwin

I can't speak to the 993 but on my '83 SC pulling that window is not for the faint of heart. I happened to find a local 'old school' glass guy that was able to do mine. I tell people all the time to not make the mistake I did. I was in a hurry to get the job done and couldn't find a 'formed' seal like the OEM Porsche ones. Most of the aftermarket ones don't fit properly in the corners and will result in the same problem you are trying to fix.

When I say formed, imagine you open the package on the Porsche seal. It will be shaped like a rectangle. When you open the aftermarket seals, they come out of the package shaped like a circle. What this means in when the aftermarket seal turns the corner, it bunches up and has a poor fit. I hoped I explained this in a way that makes sense.

Makes sense, thanks, that's the kind of stuff I need to know beforehand.

[turbo owner]

Have you tried to roll the seal back, see if maybe you can fix it without removing the glass

[yellowperil]

Originally Posted by turbo owner

Have you tried to roll the seal back, see if maybe you can fix it without removing the glass

I have, but I not sure that would be doable. Might be a temp fix at best.

But I'm a bit afraid of opening a can of worms that I might regret if I make a mess of the bigger job.

[Mark Salvetti]

I don't think you have an option. You have to pull the window. You have that rust bubble because the seal is leaking, and water has collected in the gap where it will sit for a long while. You may also have rust starting on the rear parcel shelf and the rear seat bottoms.

Check out this thread: Why windshield trim should be a regular maintenance item.

It starts out talking about cars older than 993's, but you'll see a mention that they are starting to show rust spots too. Make sure you replace with a Porsche seal, and read the pros and cons of using a sealant as well.

Mark

[FrenchToast]

Big problem on the 993s.

To properly fix the rust, the windscreen must be fully removed, and metal properly treated. New seal should definitely be applied.

If rust is visible (like in your picture) there is a good chance the metal under that portion of the seal is compromised, meaning a new section must be welded in.

If you do decide to repair it I highly recommend taking it to a shop that has done this type of work before, specifically on a 993.

It also happens on the front.

http://rennlist.com/forums/993-forum/914208-windshield-rust.html

Search in the RL 993 subforum - lots of talk about this type of rust.

It's a problem with all 911s (pre-galvanized ones are the worst of course). But the relative youth of the 993 body makes rust on the newer cars even stranger. I can only attribute it to Porsche's revamping (*cough* downgrade) of production methods in the mid nineties.

There is a TSB about it, mentioned in the thread hyperlinked above. One thing the TSB apparently mentions is if you have rust by one windshield (front or rear), you should also check the other end as well.

If you can't manage to do the repair right away, but still want to drive the car for a while, I would recommend just leaving it alone, and be sure to keep the area as dry as possible when driving or washing.

[yellowperil]

Yes the front had some rust too, and I dealt with that when I first purchased this car. Took it to a good shop locally, and we did a real good job of it. W/Shield out
and new rubber seal. We sandblasted, (they were very careful with keeping interior clean) as I worried about sand getting inside but they kept it out.

Even put a new windshield in while we were at it. So I guess I'll take it back to them. What we did was, I had a windshield shop do the in and out, and the body shop did the body/paint portion. So went well.

My hesitation now comes from the fact not many people ever get to change REAR glass, as I said previously, and NEVER on Porsches as there're almost none where I live.

But I guess we'll have a go after I get a bit organized with new parts and such.

[yellowperil]

Got the window out, no problem (for the shop that did it). Not as much rust as I thought. Car is now at the body shop for cleanup and paint. Back in a day or so.




Drivin' with no back window

[yellowperil]

And 3 hrs later we found some.

[yellowperil]

Well, body shop got their part done, a great job too. Very clean, they were very careful while sandblasting. Had everything covered. Got a good match on paint.
Went like this: Sandblast, primer, silver and finish coat of clear. Several coats of each. My friend says some shops would not bother clear coating thinking not needed in the track below the rubber, and that would be a big mistake on their part.

So the car is in my friends windshield shop till they reinstall the glass on Monday
or Tuesday when the paint is well cured. I'm lucky to have some real talented guys
for friends.

Great job guys.

Now a few pics while I was waiting for this repair. Note the look on my dogs face when I told her I was thinking of buying that BMW wagon.

Cleaned up the engine in my rat a bit, just for something to do.

[yellowperil]

and happy with the results. Cost wasn't too bad for a non DIY,