Master cylinder float question

Hi:

My 2003 Accord brake dash light came on and stayed on yesterday morning.
The main and hand brakes work fine. All tail and rear window bulbs OK.
Fluid level is topped off nicely. I pulled the low fluid level connector
off of the master cylinder and the light went out. My next thing to do is
try and get the strainer out of the master cylinder and stick my finder down
there and see if I can feel and move the float. Any suggestions would be
appreciated.

Wayne

 

what is the question?

 

Hi,
ABS is little different. Unless you know what you are doing, at least
look up the shop manual or ask a pro.

 

Isn't the float attached to the cap?

 

http://www.tegger.com/hondafaq/tsb/accord/x03-078e.pdf

I think this will help

 

In addition to what everyone else has said, I'd recommend NOT sticking
your finger in the reservoir - your brake fluid is the one thing you
want to be REALLY careful not to contaminate. (In reality, it probably
won't do any harm, but better safe than sorry...)

 

Yeah, good point, too - check the PDF link JRL provided, the float
should be attached to the cap. If it's not there, well, there's your
problem... also, it's a FLOAT - if it did come loose, it should still
float to the top when you pull the cap off. You shouldn't need to go
digging after it.

 

They stopped doing that in 2002. The 2003 Accords have the float down
inside somwhere, from what I can gather. The only thing visible is the
strainer basket subassembly, and I don't know yet if it is pressed in or
not. The connector is down low on the left side, towards the back of the
mater cylinder, when viewing it standing in front of the car.

My question is, has anyone else run into this problem. Is there a wat to
get the whitesemi-translucent resevour off without damaging it, or, if it is
the float or float switch, so I need to replce the whole master cylinder?

 

My question is, has anyone else run into this problem. Is there a way to
get the white semi-translucent reservoir off without damaging it, or, if it
is
the float or float switch, so I need to replace the whole master cylinder?

 

You remove the strainer (by hand) and replace it with a new one, just like
the TSB says. The TSB was not written just for fun, you know.

 

You da man, da Honda Einstein, Tegger. It's just that the bulletin was for
up to 02 Accords and my 03 looks different, so I wasn't sure. Besides, it's
been raining for 3 days and I was working and wasn't going to fiddle with
the problem until Saturday. Your master cylinder article was very
informative and interesting. I haven't had one of them apart since the
single circuit days, for a rebuild. Can one still buy rebuild kits? I used
to do my 70 Vega and 80 Chrysler wheel cylinder rebuilds every time I put on
new pads, because if I didn't, 75% of the time they would stick and
overheat. So far, the 03 Honda has not.
BTW, what do the porportioning valves do? Seems like the the laws of
physics say the pressure would be equal at both brake cylinders without any
valves. Also, the left front / right rear split seems really squirrelly.
Both back on one circuit and both front on the other seems normal, safer,
and not needing proportioning valves.
Also, since I've never bled my brakes in the 03, or any other car I've ever
owned, except when I lose a lot of fluid from removing a wheel cylinder to
rebuild it...........how should I flush them.......a little at a time with a
hand vacuum pump and reservior, which I can do myself........or by pushing
the pedal all the way down, which "cleans" the master cylinder better but
requires two people. Will I know I got everything when the fluid coming out
of the wheel cylinders looker cleaner, or is replacing a little now and then
good enough.
I noticed a couple of weeks ago, when I added an ounce or two of brake fluid
for the first time ever to the 2003 Accord, that the new (unused, but
probably 10 years old or more) brake fluid looked a little cloudy, making me
think I should dump it and get a new bottle. Hope that didn't cause the
float switch problem but I don't see how it could have. I guess that
container of old brake fluid absorded water just sitting in the basement for
years, even with the cap on.

Wayne

 

It might not be applicable, but it's a logical, cheap (and simple) first
attempt.

Not from the dealer for my car, but maybe for others.

I could have bought a rebuild kit from the aftermarket, but there was
only ten bucks difference between the kit and a finished assembly, so I
bought the finished assembly.

The proportioning valve splits the the brake fluid lines into front and
rear zones. This is independent of the master cylinder's dual-diagonal
split.

The proportioning valve consists of two chambers. One chamber serves the
front wheels, and one chamber the rears. Each chamber has an inlet for
the feed from the master cylinder, and one outlet for each of the two
wheels served by that chamber.

The outlets for the front wheel lines are of a certain diameter. The
outlets for the rears are choked down by an insert that makes the
diameter smaller than the outlets for the fronts. A lower fluid volume
thus flows to the rear brakes. In this manner the front brakes are
permitted to bite harder than the rears, preventing rear wheel lockup
prior to front lockup.




Also, the left front / right rear split

Toyota does a front/rear split, but still uses a proportioning valve to
ensure the rears don't lock up before the fronts.

If your pistons are all moving freely in their bores, and the fluid is
fresh, you'll never be able to tell what system of split is used.

If you have uneven braking, you have a problem at the wheels (sticky
piston). It has nothing to do with the diagonal split.

A Mity-Vac is fine. It helps to wrap some Teflon tape around the bleed
screw threads so you don't suck air into the vinyl tubing. That air will
mislead you into thinking you've got air in the brake lines.

SpeedBleeders are better. www.speedbleeder.com

This is my method. Luckily I have my wife to help me with that task.

You should replace ALL the fluid every two years. That's how you keep
your wheel cylinders in good shape nearly forever.

You can tell you've flushed it sufficiently because the fluid will be
clean and clear, a very pale straw color

Yes it did. Always use freshly bought fluid.

 

Or glaze, or pads seized, or caliper not sliding freely on pins...

 

Wayne wrote:

Is there a way to

 

The same problem presented itself with my Prelude around 60k miles. It was
the float. But I should imagine the system in the Accord may be a little
different.