A number of manufacturers have over the past few years taken to using aluminium in place of copper for sealing washers (lighter - cheaper?). Recently the trade press has been reporting cases of Volkswagens and Audis with brake leaks caused by such washers corroding to the point of failure.

I have come across Volvo using such things in some areas (oil pressure sensor banjo seals on 400s for example) but had never seen or heard of ally washers being used on 300s - until:-

These are the filler and drain plug seals from Varts old 4speed diff unit.



Not quite in the brake failure area but near to leaking diff oil though.

Ouch, that's interesting stuff Mac! Certainly something to watch out for. There are good reasons why copper was always used, if it's not broke don't try and fix it as they say, but it appears as though saving money was the deciding factor.
Pete

IIRC, the Volvo OEM ones are still copper. They use ally in certain 'low risk' situations (oil cooler pipes on a 700 turbo, for example, where it's clamped by ally on both sides), but it's mostly copper.

cheers

James

Volvo gave me an aluminium one for the sump plug washer a few months ago. Guess it's not so important for that as it come off regularly when doing oil changes, but worrying photos nonetheless!

mac wrote: I have come across Volvo using such things in some areas (oil pressure sensor banjo seals on 400s for example)

hmmm, *goes off to see the 400 banjo bolt and sensor he put onto Fake*...

Voila' - 400 oil pressure sensor banjo and aluminium washers (direct from the stealers) and 'borrowed' of the wifes 97GS.



Mac.

So should I replace those washers? I'm guessing not if the banjo is ali...

Personally I wouldn't bother - the most risk seems to be where general road salt and muck can 'attack'. Under the bonnet is pretty safe - just smear a little oil round the washer edges and you ought to be OK.

Mac

That's wierd Carl - they're normally (including in the last couple of months) copper. Naughty Volvo!

cheers

James

Carl wrote:Volvo gave me an aluminium one for the sump plug washer a few months ago. Guess it's not so important for that as it come off regularly when doing oil changes, but worrying photos nonetheless!

Same here!! It was always copper... until last year, big surprise! Volvo gave me sealing washers in aluminium... Scary pictures Mac!

In the 70s and 80s we were replacing copper washers with Aluminium because the bears were leaving the plant with pockets full of "coppers" every night.

5000 guys with 50 washers each 250 times a year is a lot of dosh.