Brake Pedal still mushy after brake job

[croweasley]

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.

 

[jim beam]

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.

 

[croweasley]

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.

 

[jim beam]

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.

 

[croweasley]

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?

 

[Woody]

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

 

[croweasley]

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

 

[Burt S.]

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.

 

[jim beam]

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.

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.

 

[jmattis]

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.

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.

 

[TeGGeR®]

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.

You've toasted your Master Cylinder seals.

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

 

[TeGGeR®]

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.

You've toasted your Master Cylinder seals.

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

 

[Burt S.]

You've toasted your Master Cylinder seals.

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.

 

[Burt S.]

Burt S. wrote:

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.

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

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.

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.

 

[Don Lee]

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.

 

[Alex Rodriguez]

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.

You've already gone too far.

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.

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

 

[Alex Rodriguez]

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?

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

 

[TeGGeR®]

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,

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 no damage caused to the
seal by using the full cylinder travel.

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.

after all, 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?

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.

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,

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.

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.

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.

 

[jim beam]

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

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

 

[jim beam]

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.

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

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

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 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.