Brake Pedal still mushy after brake job

Myself and a friend of mine just put new brakes on my 1991 Honda Prelude
Si. We did the rear brakes, replaced the calapers, rotors, pads and then
bled them all, front and back. We bled them all 3 times and refilled the
brake fluid in both the booster and the ALB system. After all this the
brakes are still very soft. I have to press the pedal almost all the way
down to get any stoping power.

 

did you service the master cylinder? replace seals or replace the whole
thing? if not, that may be your problem.

 

no, all we did was the rear brakes, i was hoping i wouldnt have to spend
the almost 150.00 dollars for the master cylinder. You see, i am short on
money and that would take damn near my entire check. Any other ideas would
be nice, cheaper ones are prefered, i will check the seals though, thanks.

 

you may be able to get a seal kit, but they're usually still not that
cheap. and replacement is much safer if you don't have much experience.
also, make the investment in a flare nut wrench or you could round off
the pipe connectors.

 

thanks for the assist. I will try to do that, i need to get all new tools
anyways, my are all standard, i dont have but one thing that is metric.
Anything else i should know?

 

Try bleeding the brakes again, all four, not just the back.It is possible
you still have air in the system....

 

will do, now i have another question. the other guy that was nice enough to
reply said to check my seals and brake cylinder. if it is the seals, or for
that matter the cylinder, how long can i go without worry. i know that i
need to do it ASAP because it is my brakes that i am talking about here.
but i simply dont have the money to shell out and my girl has to use the
car to get across town everyday. so will my brakes go out on me soon or at
all or how long do i have? the cylinder is 150.00 bucks that i cant afford
considering i skipped out on rent to shell out 120.00 into the rear
cylinders this week. thanks again. Crow

 

I don't believe normal bleeding would damage the master cylinder, unless
you push the pedal all the way to the floor. Put a block of wood under the
brake pedal to keep it from going too deep.

Bleed them in the correct order with the correct procedures. Tips:

Tap on the piston or what not to release the air bubbles. Until the person
pressing the brake feels some overall firmness then you know it's time
to abort the bleeding. Have another to make sure that the reservoir is
always full. Try not to leave the fluid expose to air for too long. Use clear
tubes, if not already. Bleed sequence:

FL Driver side, RR rear passenger, FR front passenger, RL rear passenger.

 

that's an old wives tale. unless the bore of the cylinder is /severely/
corroded, something that doesn't happen very much in the aluminum
cylinders used in hondas, there is no damage caused to the seal by using
the full cylinder travel. afterall, emergency braking uses a lot more
travel than standard braking - surely no one is going to start saying
that you shouldn't emergency brake as well?

truth is, most brake systems don't get their fluid changed regularly
enough. contaminated fluid swells seals. when old seals get new fluid,
i.e. when the system is bled, the new fluid shrinks the seals slightly,
and if they're old enough, they shrink enough to leak. the fact that
leakage happens a couple of weeks after a fluid change leads to a
mistaken assumption that the system was "bled wrong". no. the seals
were just old and were going to fail soon anyway.

 

truth is, most brake systems don't get their fluid changed regularly

A good reason not to bleed them at all, and I wish Honda would get off
of this.

Ford did a study several years ago, showing that after 10 years never
being flushed, their brake systems had 1.4% water. They also found
that nothing short of 3.0% water was going to hurt anything.

Nissan for instance does not recommend brake flushes. Had my I30t
nearly 10 years and it never had one, thank you very much. No problems
after 111,000 miles.

I had the stealer bleed my '90 Integra twice, at 3 year intervals as
recommended. Result was having to replace two master cylinders, both
at my expense. You can bet it was never bled again after that. And,
no further brake problems.

If Hondas really need bleeding, to protect the ABS some will argue,
then what they really need is a better design.

 

You've toasted your Master Cylinder seals.

http://www.tegger.com/hondafaq/mastercylinderreplace/index.html

 

You've toasted your Master Cylinder seals.

http://www.tegger.com/hondafaq/mastercylinderreplace/index.html

 

He mentioned mushy and almost all the way down, not all the way to
the floor. This could be the symptoms of air in the system probably from
sucking air thru the piston seal at the wheels.

 

I'd neglected to mention that this doesn't happen to all the vehicle
but only to the seriously neglected.

I worked on a couple cars with the OP's symptoms and all was
needed was a proper bleed. Yes, possible that the seal could shrink
but the cost of a new seal is too high (based on his request) to forget
a basic simple step.

 

I had a similar experience once. It turned out to be air in the system.
Finally fixed it by a careful and thorough bleed. The trick seemed to be
pushing the peddle forcefully to get rid of the trapped air.

 

You've already gone too far.

$150 is cheaper than having to fix the damage from an accident.

 

The EB system is mechanical, completely different from a hydraulic system.

 

First off, I messed up, being distracted by another debate. The OP's
problem was a SPONGY pedal, which as others have already pointed out, means
air in the lines. An amazing number of people run the MC too low while
bleeding, suck air in, then hope beyond hope that they didn't really do
that.

Since the OP has ABS (ALB), that introduces an ugly variable to the
problem: You have to bleed at /least/ three times to do a proper job: Once
for the primary system, once for the ALB, then once more for the primary
system to catch what came out of the ALB. and that's for EACH CIRCUIT.

Secondly, corrosion DOES happen to ALL MCs if you don't flush that water
out of there. Aluminum corrodes in the presence of water. Period. All it
takes is a few little black spots in the bottom of the bore to scrape up
the seals. Won't happen overnight, but it *will* happen.

There is. If there is corrosion, that is. Which there usually is with most
cars after about 6-7 years or so.

Well, in your neck of the woods, maybe not. SoCal is an almost unique
driving environment. I've been there twice, and I can tell you that most
people do not have it quite so easy as you do.

Most owners never change their brake fluid. EVER. By the time you get the
chance to service their neglect, the stuff is black and slimy, and under
that are those evil little black dots of aluminum corrosion.

George Macdonald used to recommend sucking out the old MC fluid with a
turkey baster before bleeding. With a few more years under my belt, I can
see why he said that.

Define "emergency brake". If you mean the parking brake lever, then that
has nothing to do with the Master Cylinder. If you mean pressing the pedal
to the floor because you had to to stop the car, then you have some pretty
serious issues there.

Jim, that's an old wive's tale if I ever heard one. Those seals are a
variant of neoprene. They do not swell or shrink, they just wear out. They
get flat on the outer lip.

Don't need that. Every eight full pedal pumps, refill the reservoir.




No problems there. It will be exposed to the air for the next few years in
your master cylinder anyway. The MC's vented, you know.





Not for Hondas. For our cars you bleed longest to shortest. Since Honda
uses a diagonal split, it's RR, LF; LR, RF.

 

ok, terminology. i'm referring to panic stopping, not using the hand
lever. panic stopping uses /much/ more pedal travel than normal.

 

and ford are the biggest cheapskates in the industry - bar /none/.

http://www.findarticles.com/p/articles/mi_m3102/is_9_123/ai_n6221217

you won't find a single automotive textbook that agrees with you on that
one. brake fluids lubricate, suppress corrosion, transmit compression
and condition seals. /all/ those properties degrade with time and
moisture content. /i/ flush my fluid every year. and i have no
problems. your 3-year schedule is about the worst possible - it allows
the fluid to become thoroughly contaminated, then replaces it and the
seals re-size from a contaminated state. and so they leak. so, should
you /never/ change the fluid or do it regularly? if there's any chance
you'll ever need the vehicle worked on, [rhetorical] you need to have
the fluid flushed like it says in the book so you /don't/ have exactly
the problems you describe.