centara

I typically had my Accord 2006 SE serviced by a local Honda dealer and my second brake fluid replacement was no exception.

However, from the invoice, I quickly realized that the technician used a Valvoline Professional Series (VPS) DOT 4 which was obviously against my Accord 06 owner manual.

"Always use Honda Heavy Duty Brake Fluid DOT 3. If it is not available, you should use only DOT 3 or DOT 4 fluid, from a sealed container, as a temporary replacement.

Using any non-Honda brake fluid can cause corrosion and decrease the life of the system. Have the brake system flushed and refilled with Honda Heavy Duty Brake Fluid DOT 3 as soon as possible. "

When I showed this paragraph to the service advisor, he first tried to convince me that the VPS DOT 4 is better than Honda HD DOT 3 and all Honda deals are using VPS DOT 4 as recommended by Honda. I asked for an official proof from Honda which he cannot provide. His service manager tried to call someone (presumable a Honda employee?) but did not succeed.

Eventually the service advisor let me make a decision whether I would like to replace the VPS DOT 4 with Honda DOT 3 free of charge. It was too late and I told him that I would let him know a few days later.

Now, my humble question is whether I should ask for a replacement from a safety point of view? BTW, The new fluid gives me a softer brake feeling than Honda Dot 3 just replaced.

Any suggestions are more than welcome

FishyMan

i've had dot 4 in dot 3 system b4. don't know about softer feel though.

lovelove

What ever your car is recommended for, use that only because who knows it best; the mechanic or the engineer? Specifically the engineer because they designed that car to run whatever and however. To answer your question, I know for a sure fact that the boiling point of the DOT 4 is a whole lot than DOT 3 brake fluid. So go back and get it flush and use the approve brake fluid for your vehicle.

Another useful source of information is to check out this website; scroll towards the middle where they talk about the DOT Ratings.

http://www.stoptech.com/tech_info/wp...fluid_1a.shtml

MSchu

as long as your system is not running silicone, you are fine.

DCFIVER

Honda coolant, ATF, MTF, and differential fluids are all proprietary fluids. They were specifically designed for specific engine, trans,etc.... Brake fluid and power steering fluid on the other hand are generic. Dot 4 has a higher boiling point but is also more hygroscopic. Both DOT 3 and 4 are interchangeable. There are ill effects to both fluids, but nothing dangerous or life threatening. I'd save myself a trip and keep the fluid you have now.

As for the softer pedal, my guess is some air was allowed into the system during the flush.

centara

Many thanks to all of you.

The following is what I just learnt from stoptech.com

"As a trailing note on the DOT ratings, if your car was designed for a particular type of fluid (especially prior to the development of DOT 4 fluids), you should make every attempt to stick with that fluid! For example, if your car was delivered with DOT 3 fluid, the internal components of the system (seals, brake hoses, and fittings for example) were specifically designed and tested for compatibility with DOT 3. Because DOT 4 fluids contain a different chemical composition, the system may not necessarily react in a positive fashion to the borate esters floating around in the mix.

In other cases, just the difference in viscosity of the two different fluids may cause the seals to wear at different rates. What starts as an annoying squeak might eventually become a torn seal or worse. The examples could go on and on, but the message here is this: it’s fine to upgrade from DOT 3 fluid A to DOT 3 fluid B, but you should think twice (maybe even three times) before switching from DOT 3 fluid A to DOT 4 fluid of any sort.

That said, when dealing with modern hydraulic braking systems a numerically higher DOT rating is typically considered to be compatible with a lower DOT rating (except for DOT 5, of course). Unfortunately, this same generality just isn’t true for most older hydraulic system materials."

It appears that I may have to ask for a replacement of my brake fluid.

lovelove

Good Job!

centara

Finally the VPS DOT 4 was replaced with HG DOT 3 and the softer pedal has gone. I got my sensitive yet linear pedal back

DCFIVER

Its funny how people see, hear, or read selectively only what they need in order to prove a point or solidify decisions that have already made. The last paragraph that you used to enforce your notation that the dealership some how screwed you over was only in refrence to OLDER braking sytems. You convinently glossed over the last part of the article, so I will single it out here so that others will not be misinformed by your bias:


"...that said, when dealing with modern hydraulic braking systems a numerically higher DOT rating is typically considered to be compatible with a lower DOT rating (except for DOT 5, of course). Unfortunately, this same generality just isn’t true for most older hydraulic system materials."


DOT 3 and 4 are compatable in TODAYS automobiles. The down sides to mixing the two would vary between the fluids themselves, but would not adversely affect the brake systems seals or lines.