I was planning to flush my whole brake system and replace the brake fluid with some ATE DOT 5.1 as replacement fluid. However, I noticed in the owners manual that it says: "always use honda heavy duty brake fluid DOT 3. The use of any other fluid can cause corrosion and decrease the life of the brake system." Is there any merit to this?

 

If this is a street car or an occasionally tracked car, anything beyond is Vavoline SynPower Synthetic is wasted money. It's like $5 for a 32 oz bottle. You'll probaby use just over a 1 bottle if you do a full flush. Might as well do the clutch slave while you've everything out and up on jack stands.

ATE SuperBlue & Type 200 are fully compliant with mixing with DOT 3 & 4. DOT 5 is different than 5.1. DOT 5 can't be mixed. Unless you running race pads and race tires, you don't need ATE.

 

Yeah it is just a street car, but I was just going to use ATE because I have some already that I use in my sportbike because I track that. I was just wondering about this warning, what is different about the honda DOT 3 that the manual suggests not using any other brand of DOT3 or 4 as it will cause corrosion and brake system damage?

 

I suppose Honda has tested and spec'd the Honda Fluid. But any good type 3, type 4, or type 5.1 fluid will work. Maybe a really cheap fluid would not, I don't know.

For a street car I'd just use the Honda stuff -- it's cheap. For a track car you need at least DOT4 -- I use ATE SuperBlue alternated with Motul 600. But that's just a waste of money for the street.

Also, most track cars get their fluid changed at least once a year. The longer you keep the fluid in the car, the more it will absorb water, and so the more it will be corrosive.

 

Pay attention to the bottle, 'regular' Synpower fluid does not have the numbers that the 'high performance' Synpower fluid has so it is not suited for track use. You must read!

All that stuff about Honda fluid is standard boiler plate.. a quality 5.1 will work well for you.