Honda Break Fluid

My Honda Civic 2002 owner's manual states that the break fluid MUST be
replaced every 3 years. Furthermore, it states that ONLY Dot 3 Heavy
Duty Honda break fluid must be used. The manual states that the use of
other break fluids apart from Honda's will result in system corrosion.
My mechanic tells me that I should not bother about only using Honda
break fluid, and that he is using Dot 4 in his shop. He says that what
the owner's manual says about only using Honda break fluid is nonsense.
Should I believe him and use his Dot 4 fluid?

 

DOT 4 has a higher boiling point and is superior to DOT 3.

DOT specs are universal across brands...

JT

 

Right! But, is the manual right if you use other fulids it results in
system corrosion?

 

Hondas don't have break fluid. American cars do--they break every
couple of weeks.

 

Stick with Honda brake fluid. I don't know for sure about Honda brakes, but
the risks of not using Honda fluid when the owner's manual calls for it are
unacceptable.

When I had a Lotus in the early 70s I bought a parts man's story that any
DOT 3 brake fluid would work, and it did... for a while. One morning I went
out to drive and when I stepped on the brakes the pedal went straight to the
floor. The DOT 3 had destroyed the secondary seal in the master cylinder
(which had the bad fluid on both sides) so the warning light never came on,
then destroyed the primary seal (which had bad fluid on only one side.)
When I tried to rebuild the master cylinder I found it had pitted inside and
was scrap. Sound like fun to you? Anyway, if I had used Girling fluid as I
should have I would have been spared.

The DOT spec is a minimum performance spec and has nothing to do with
special properties that may be required. You will be money ahead to pay for
the Honda fluid if the manual calls for that.

Mike

 

All conventional (DOT 3/4) brake fluids are hydroscopic. All will absorb
moisture and eventually corrode brake systems. Flushing (by bleeding)
the system every two to four years will take care of this issue.

DOT 5 brake fluids are silicon based and do not absorb moisture.
However, other issues must be addressed when using these fluids.

HINT: Dealership service is a big profit operation, much more so than
the sale of the original vehicle. Sorta like the ink jet printers where
the real profit is made on replacement cartridges when the original
printer was sold for little or no profit...

JT

(Dealers are generally NOT your friend..)

 

Thank you Mike for sharing your insight! Knowing what you went
through, I am going to stick to Honda break fluid for sure now!
Cheers

 

"Dealers are generally NOT your friend" I agree!

Not knowing about break systems in cars, I can only trust the owner's
manual or people with intimate knowledge of what is going on that might
corrode break system. Your answer defiantly helped me to understand a
bit more. Thank you!

However, I think I am going to pay a bit more and take my car to the
dealer for this particular service.

 

I change my BRAKE fluid every YEAR. This way I prevent my BRAKES from
breaking.

And I'll bet he uses ATF in Honda power steering systems too.

Honda is quite specific with some of their fluids. The BRAKE fluid in your
car is one of them. Excerpt from your car's factory shop manual:
"Always use Honda DOT 3 brake fluid. Non-Honda brake fluid can cause
corrosion and shorten the life of the system."

You can listen to your mechanic if you like, but is he going to pay you for
any BRAKE system damage that may occur?

Don't be a cheapskate, do the job right. Have you prices ABS parts lately?

 

It's spelt BRAKE, not "break".

The primary reason Honda specifies their own branded brake fluid is that
this way they can avoid the variability in quality of aftermarket fluids.

All brake fluids contain anti-corrosion additives, some more and better,
and some less and worse, than others. The use of low-quality fluids will
result in accelerated corrosion on account of poor quality corrosion
inhibitors.

Such parts as ABS modulators will suffer extremely expensive damage over
time from the use of fluids with poor corrosion protection.

Excellent idea. An extra fifty bucks here will save you thousands later.