I have used DOT 5 in my suburban, but only for about 4 years. All parts in the brake system were new, so there was no concern about contamination. I did contact vendors to screen wheel and master cylinders to confirm they were DOT 5 compatible (not all vendors would confirm compatibility).
The only problem I had was a bad new master cylinder from Jim Carter. I guess that I should have first taken it apart and cleaned it. It had oil or grease in it and this did not allow the piston to return (after driving it for about 500 miles).
Tim
