SSBC & DOT 5 fluid

I installed SSBC disc brake conversion on my Dart and used DOT 5 brake fluid

everything was OK for 4,000 miles and then going to the car show a few weeks ago the pedal felt soft, once there fluid was leaking onto the left front wheel & tire

I called SSBC and they said send it back, ask if the DOT 5 fluid might have been part of the problem, they said might have.

Do you use DOT 5 brake fluid and have you had any problems?

These parts were new and never had any other fliud in them.

Could the DOT 5 fluid caused the rubber seals to deteriorate/ will I need to replace both sides?

It will be interesting to hear what SSBC has to say about the problem. I think they must have wanted to see the part and why it failed. He did not suggest a rebuild kit, just send it back.

What do you have to say?