Don wrote:Interestingly, neither GM, Ford or Chrysler have any recommended change interval for their vehicles which came factory equipped with DOT 3/4 fluid. GM says that additives in it's Delco DOT 3 brake fluid make it 'essentially a lifetime product'
Modern brake systems are pretty well sealed. While it's true that the glycol based fluids are hygroscopic and will absorb moisture if left open to the atmosphere, any sealed brake system gets contaminated with moisture at about the same rate, no matter what fluid is used . . . . but a percent or two of water in a glycol system is much less of a concern from either a corrosion or a boiling standpoint than same amount of moisture in a silicone system
It appears we have so many folks here who have had such phenomonal success using all types of brake fluid, that no reader should worry a lick about whatever fluid they're using
Brakes, for me, fall into the same category as parachutes and condoms. Failure for any one of them usually has serious consequences, so I do what I can to keep things in good order.
General Motors and Chrysler do not mention brake fluid in their schedule maintenance recommendations, so it is "essentially" a life time fluid. Must be the same stuff Rick has in his 60+ yr old trucks....
The use of the word "essentially" has me a bit concerned though. Much like "life-time" warranty on things that have a 2 yr life expectancy, I don't get a warm and fuzzy feeling when "essentially" is used in conjunction with brakes and I'm doing 100 mph approaching a 90 degree corner.
Ford recommends fresh fluid every 36k miles or 3 yr change-out....and replace the fluid at each pad change.
Chrysler does recommend brake fluid change every 2 yrs on their Sprinter vans. Must be a euro thing as Europeans still think brake fluid changes are a good idea:
2 yr. brake fluid change-outs are recommended by Audi, BMW, Jaguar, Mini (BMW), Smart, VW, Mercedes and Volvo.
36 month change-outs are recommended by Acura, Honda, Land Rover, Lexus.
Thanks but no thanks Don...... I'll stick with changing my DOT 4 brake fluid every 2 yrs in the vehicles that still have it......but rest assured, when it comes time to do a full rebuild it'll get DOT 5 like the rest of my fleet.
Btw..... looking further into your 17 yr old Miata brake fluid.... "Mazda recommends only that the brake lines, hoses and connections be "inspected" at 30,000 mile/30 month intervals; replacement of brake fluid is not mentioned in the shop manual for U.S specification cars.".......so you are good for another 20--30 yrs it seems.
There was a asterisk to this statement however, ."The Miata Club of America has recommended brake fluid replacement at two year intervals."......so you might want to reconsider your brake fluid situation.
Coming full circle...... DOT 5 beats all these recommendations by years with it's 5--10 yr change out, no harm to paint and plastic when spilled, which is so easily done with bikes......and being non-hydroscopic it doesn't absorb moisture.
My best........ Mike