The car had sat with silicone fluid for 25years it had a very spongy pedal and not wanting to cut corners with brakes I bought an overhaul kit (new master cylinder, wheel cylinders,springs,hoses etc). I pumped a couple of litres of alcohol though the old system until clean alcohol came through followed by compressed air.
I installed all new parts and used dot 3 fluid (largely because dot 5 wasn't easy to come by in Australia, although I found it afterwards), even though the car is up on stands the brakes felt good and a nice solid pedal feel.
A week or so later I was under the dash connecting a wiper motor I lent against the pedal and it went to the floor, I checked for leaks and found none but tightened up all the connections and re bled the brakes however in a little over a week the fluid had gone from bright blue to almost black. I pulled the master cylinder again and took it apart there were very tiny metal shards in the bore but the seals looked visibly good (although the check valve looks upside down on the spring compared to the illustration in the shop manual).
After speaking with SI (where I bought the parts) it was suggested that trace amounts of dot 5 have mixed with the dot 3 to cause a chemical reaction weakening the seals, can anybody suggest what may have happened or measures to fix it ?
Thanks
I installed all new parts and used dot 3 fluid (largely because dot 5 wasn't easy to come by in Australia, although I found it afterwards), even though the car is up on stands the brakes felt good and a nice solid pedal feel.
A week or so later I was under the dash connecting a wiper motor I lent against the pedal and it went to the floor, I checked for leaks and found none but tightened up all the connections and re bled the brakes however in a little over a week the fluid had gone from bright blue to almost black. I pulled the master cylinder again and took it apart there were very tiny metal shards in the bore but the seals looked visibly good (although the check valve looks upside down on the spring compared to the illustration in the shop manual).
After speaking with SI (where I bought the parts) it was suggested that trace amounts of dot 5 have mixed with the dot 3 to cause a chemical reaction weakening the seals, can anybody suggest what may have happened or measures to fix it ?
Thanks
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