Air conditioning leak sealant

[nfearn]

In common with many older Porsches my 993's air conditioning was leaking its refrigerant. Mine was probably leaking from the evaporator (the unit through which the air destined for the cabin is blown in order to cool it) although the leak was small so it wasn't easy to properly confirm this. The system would empty itself over a couple of months.

Having researched the process for the replacement of the evaporator I was resigned to a long DIY job (removal of fuel tank and much else, taking ten or more hours). However, some further research showed that there are some products on the market which claim to be able to plug smaller leaks.

To cut a long story short, I checked with the garage I use for BMW servicing and they said they were trialling this type of product. Result- for about £100 including labour I now have a fully working aircon system that has been going strong since March this year. The charge included re-gassing the system.

According to the garage, the general thinking is that if the system has a leak that is big enough to allow the refrigerant to leak out more or less completely in a couple of weeks, then the leak is too big to fix with this approach. If the system will hold pressure for more than a couple of weeks, this type of fix is reasonably likely to succeed.

I hope this information is useful to those with similar problems.

PM me if you want to know which garage I used - they are based in St Ives in Cambridgeshire.

 

[ColinC]

I have the same issue......have a leak from the big pipe that runs along the sill just at the mount. There is a TB about this which updates the mounts to prevent rubbing and subsequent corrosion............anyway when I replace the pipe and mount I may as well get some sealant in there with the regas.

Do you know what the brand of sealant was?

I used Kwik Fit for the initial gas and they will regas at a discounted rate so maybe they can do the sealant at the same time, in fairness they were OK once they realised where the engine was...........no really!

 

[nfearn]

Interesting - I was not aware of the TSB. Is it online?

I've checked the invoice but it doesn't specify a product brand.

 

[ColinC]

Try this

http://pcarworkshop.com/images/7/7c/8743_1996_6tu80196geolab.pdf

 

[nfearn]

Thank you for that.

Does anyone know if the area of potential corrosion is accessible from within the wheel arch (with the liner removed)?

 

[ColinC]

It's the two rubber mounts under the plastic beneath the sill. Really easy to remove 3 or maybe 4 10 mm plastic nuts and a couple of screws that connect it to the arch liner...........Good to remove both sides as I found a lot of 'road clug' under there.....

 

[nfearn]

Very useful to know - thank you.

 

[Mike M]

ORIGINAL: ColinC

I have the same issue......have a leak from the big pipe that runs along the sill just at the mount. There is a TB about this which updates the mounts to prevent rubbing and subsequent corrosion............anyway when I replace the pipe and mount I may as well get some sealant in there with the regas.

Do you know what the brand of sealant was?

I used Kwik Fit for the initial gas and they will regas at a discounted rate so maybe they can do the sealant at the same time, in fairness they were OK once they realised where the engine was...........no really!

Thanks for the heads up Colin. Im getting the big pipe you mentioned changd on Thursday so weve just ordered the new brackets. I cant believe Porsche dont link a product with a TB that may affect that product! Shame I hadnt known about the corrosion issue in the 1st place before I had a new evaperator installed to try and solve a leaking A/C system.