brakes on all four tires now the brake paddle is soft?

check for clearance of rear brakes,hand brake movement range can help you.too much swing going up means you need to adjust the rear slave cylinders.it does not adjust automatically unlike your front brakes. I would suspect there is air in the lines. These guides can help you fix it.

https://youtu.be/w7gUsj2us0U

and

https://youtu.be/WDxvEQrMkBg

and

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

Please run down these guides and report back.

I was driving just as normal one day then all the sudden my brakes had went out on me. My foot hit the floor and I was unable to stop the car. The brake pressure isn't good at all. It normally takes me going halfway down to actually begin to stop the car. I had the brakes bleed twice so far (all four) and the pressure was okay for three days. When I get inside the car they are firm but after I start my car the pressure is lost. It basically takes me braking to the floor then letting off the brakes and braking again to fully stop the car. The brakes are getting worse every time I drive but my fluids full every time I look at it so I don't think I have a leak in them.

This is a typical symptom of internal leakage inside the master cylinder. The brake fluid is bypassing the leaking lip seals rather than getting pushed out to the wheels. The fix is a rebuilt master cylinder. If you want to replace this yourself, I have a tip that will let you avoid having to bleed at the wheels.

I have a 94 Honda Civic LX with about 114,000 miles, 4 cylinder and on hot days my while stopped at a light my brake pedal will lose it's pressure and sink to the floor, does not do it all the time. Then when braking it feels like it pulls to the side. Are these two things related and could they be caused by air in the brake system. Any advice would help, thanks.

Which way is the vehicle pulling when you brake? The opposite side is most likely the side where your brake fluid leak is.

Check for leaking calipers, flex hoses, rotted lines, wheel cylinders, even a faulty master cylinder.

1994 Honda Civic ABS, Lx. I have all disc brakes. I just installed new brake pads on all four. I bled all four brake systems the proper way, starting from rear right, front left, rear left, then front right. The brake pedal still has little to no pressure. When I apply pressure on the pedal when the engine is off, it starts with no pressure (goes all the way to the floor) then after a pump or two it has some pressure but never maintains the pressure, pedal goes to the ground slowly. I turn the car on and there is never pressure, it goes to the floor all the time basically. What suggestions do you have to solving this pressure problem? Would flushing the brake system help at all?

Sounds like internal leakage inside the master cylinder. That is commonly caused by running the pedal all the way to the floor during bleeding. Crud and corrosion build up in the bottom halves of the bores where the pistons don't normally travel. When the pedal goes all the way down, the lip seals get ripped on the corrosion. It's okay to go all the way down with a new or rebuilt master cylinder, but with an old one, pretend there is a block of wood under it and never go more than half way to the floor.

These guides will help us fix it

https://www.2carpros.com/articles/brake-pedal-goes-to-the-floor

and

https://www.2carpros.com/articles/how-to-replace-a-brake-master-cylinder


The clue to determining if this is what happened is to pump the pedal rapidly to see if it will build pressure, then hold it but if necessary, ease up on the pressure a little then push harder again. If the pedal suddenly falls away and there's no external leaks or loss of fluid in the reservoir, suspect the master cylinder needs to be replaced.

I suspect it is the master cylinder also. I'll look into getting it replaced and update afterward. Thank you so much for the quick and thorough answer!!

I forgot to mention the motor revs up slightly when I apply the brakes right now. Any clue what is going on?

I wouldn't worry about that just yet. If the brake pedal is moving with little pressure, there might be a lot of vacuum being lost in the power booster with each stroke. The engine will respond just like if it had a vacuum leak but the engine speed should come back down in a few seconds if you hold the pedal down.

Do you think I would need a new brake booster also? or only the master cylinder?

Just the master cylinder. I never heard of a bad booster in all my years of mechanicing and teaching, . . . until a few years ago. GM owners have their own set of problems, but for the rest of us, about the only thing that can happen is the diaphragm develops a leak. You will hear the hiss when you press the brake pedal. That opens a valve to let atmospheric pressure in so the engine vacuum can pull on it.

When replacing/repairing the master cylinder, before reinstallation, ensure the seal between the master cylinder and booster is in good condition. The seal tends to fail resulting in vacuum leakages.

Thank you cardadiodoc and KHlow2008 for the helpful advice. I'm now going to work on the car. I'll update when I can. Thanks again. This forum has been very helpful in troubleshooting this frustrating problem!

So I changed the master cylinder today and the problem is still the same. I bled all four brakes and the brake pedal still goes to the floor when the car is turned on. Any ideas?

If you have the parking brake built into the rear calipers, it's possible they aren't adjusted up yet. I'm not real familiar with Honda's rear disc design, but for some other brands, the rear pistons will not self-adjust out from just pumping the brake pedal like in front calipers. The rear pistons will move out like normal when you press the pedal, but they will go back in when you release the pedal. What you may have to do is work the parking brake multiple times to walk the rear pistons out until the pads contact the rotors. If the cables are rusted tight or you don't trust them, you can use a pliers to work the levers on the calipers back and forth until the pistons come out.

If you have this design, you wouldn't have been able to just push the pistons back into the calipers to fit the new thicker pads in. You would have had to use a special tool to screw the pistons in.

Ensure you have sufficient free play for the handbrake lever. Without sufficient cable free travel, the rear calipers would not self.

1. Was the master cylinder bench bled before installing?
2. Is the master cylinder of the correct size?
3. Is there sufficient/excessive brake pedal to booster free travel?
4. While bleeding the system, was there a lot of air in system?
5. Is the ABS system working correctly?
6. Did you perform bleeding of the ABS master pump? System is under high pressure so be careful when working on it.
7. Does pumping the pedal brings it up and does it sink when pedal is held?
8. Did you check all the caliper slider bolts for smooth movements?
9. Was any caliper pistons difficult to retract while replacing the pads?

1.Yes.
2.Yes.
3.I don't know what this means?
4.No.
5.I haven't taken the car off jack stands yet. I've been turning the car on and pressing the brake pedal in. Should I put the car down and test the brakes? Will this make a difference?
6. I did not bleed the ABS master pump. Will I have to do this?

Cardio - I did have to use a tool to push the rear caliper pistons in. I'm not clear about working the parking brake. However I did pull it up at first and it felt like nothing was happening and I kept pulling it and then it went to normal. I think this is what you mean by working the parking brake.

I'm going to do another rebleeding. Hopefully I'm just bleeding it incorrectly.

Here goes...

Yup. You got what I meant by "working the lever". When you started to feel resistance is when the pistons came out far enough to contact the pads and rotors.

You might consider KHLow2008's suggestion about bleeding the ABS unit. Some vehicles require a scanner to activate some of the valves so the air can escape. This is particularly important if the master cylinder ran dry, or in your case, you replaced it. Here are a couple of tricks you might find useful in the future:

When the hydraulic system is opened, as in when replacing a caliper or brake line, fluid will drain out of the reservoir. If allowed to occur, you will have to bleed the system to the wheel you were working on and you may have to bleed other wheels too. To stop the fluid from draining out, use a stick from the seat to the brake pedal to hold the pedal down a couple of inches. The lip seals in the master cylinder will block the fluid from flowing while you do the work. When you're ready to bleed what you worked on, remove the stick, keep the reservoir at least half full, and gravity-bleed as necessary. Don't fill the reservoir to the top unless you have all new disc brake pads installed. If there are worn pads, you're going to have to push the pistons back in when you install new pads in the future and the fluid behind the pistons will go up to the reservoir and overflow creating a mess.

The second trick applies to replacing the master cylinder but only those that have two steel lines coming out, not four. Crack the soft metal nuts loose so you don't have to struggle with them after the master cylinder is unbolted from the booster. When it is off, use it as a lever to bend the steel lines upward just enough so the fluid doesn't run out. Do your normal bench-bleeding on the new one, then screw the two lines onto it. Finger tight is sufficient. Use the master cylinder to bend the lines back down, then install it to the booster. Loosen the nuts just a little, then have a helper press the brake pedal very slowly so it takes about 10 seconds to go half way to the floor. You'll see air bubbles come out by the line nuts. Snug them up before your helper releases the brake pedal. The pedal should be allowed to pop back quickly. By pressing it slowly, any air bubbles in the lines will tend to stay where they are or they will float back up. By releasing the pedal quickly, the fluid rushing back up will wash the air bubbles up into the reservoir. This will prevent you from having to bleed at the wheels.

For the ABS pump, remove the pump relay and use a fused wire to jump the terminals and make the pump work momentarily. You would know when the pressure has built up sufficiently when the pump noise slows down. Give that a try and see if the pedal increses in height.

For item #3, if the booster push rod had been adjusted out of specs, it can result in the brake pedal being too low.

Success!! I had to buy a one man bleeder kit from the store. I bled the brake system 5 times then turned the car on and bled the system one more time. I drove it around the neighborhood and the brake systems work perfectly!! I started the job thinking I just needed to get pads all around, but then found out the master cylinder needed to be replaced from this wonderful forum. Thank you for your help cardio and KHLow! The entire job ran about $150. I saved so much money doing it myself. Now I have thick pads all around and a strong braking system. Peace of mind!

All right. One in a row! Happy to hear you can safely buzz off into the sunset. I mean "sail off", not buzz off!

My muffler was broken from the previous owner, so I removed it while doing this job. So it does sound more like a buzz when i'm driving without a muffler! Thanks for the help!

ok im in serious need of some help cause i dont want to just go and start replacing parts.

what it is, is that when i push the brakes the pedal goes to the floor, but itll still stop the car, but when i do a really hard pull and go to stop afterwards the brakes are tight on it like it should be ive done bleed the brakes, and read a couple different fourm and they are saying it could be the brake master cylinder or the brake booster, i need help.

Thanks

A faulty booster will give you a very heavy and hard brake pedal, to test booster, with engine off, pump pedal until it becomes hard, hold foot on pedal and start engine, pedal should suck down a little, i would be thinking that you have air in the system, so start with a bleed and see how that works, if you cant see any signs of a leak, pull the master and check the rear seal, often you get a leak there.

Well I bleed the brakes and got all the air out but it didn't help the brakes when the car is running, I pulled the master cylinder and its not leaking either, and I tested the booster by pumping the brake with the car not running and then holding the brake down while I crank the car and it started once and the pedal fell to the floor, so I repeated the process and the car wouldn't start if I had the brake pedal down but once I let off the pedal and turned it over it would start automatically on the first turn of the key

This does not make any sense, i can't see here there would be any connection, so to isolate the two items that may be connected, disconnect booster vacuum and plug line, try starting with brake depressed, and disconnect brake light switch and try a start and see if there is any change.

Ok well I went and got a brand new master cylinder and replace it and bleed all the brakes again and figured out that I also had a bad rear wheel brake cylinder so I replaced that as well and then re bleed the brakes again, well that worked perfect now the pedal is hard as a rock and it takes a couple minutes to stop the car, but I hear a loud clicking when I'm hitting the brake.

Hey im having a brake problem on my 1994 honda civic cx. I just bought it, it had a bad cv axle and caliper. Replaced them both and now i have very little brake pressure when i start the car. Before i start the car the pedal feels good and firm from bleeding it and once u start it, it looses alot of pressure. I can still stop but it comes close to hitting the floor by the time it starts to stop. I dont remember if i said abs cv axle or not does that make a difference? Any info would be great

try rebleeding your system or have a pro do it. make sure master is full when you do this.

I do all my own work i know how to bleed brakes. Ill do it again and see thanks for the reply.

Check rear brakes and adjust if required. Too much clearance between the drum and shoes would result in the symptoms you mentioned.

If the pedal is dropping under light pedal pressure, you may have a bypassing brake master cylinder, if you hold firm pressure and it stays up look into this as well.

The brake pedal goes right to the floor. I have bleed the brakes several times. there are no leaks. What could be the problem?

there is no visible leaks, the lines have been bled and the pedal still goes to the floor, Does the pedal go to the floor with the engine not running and can you pump them up? Has the master cylinder every gone completly dry? Lets try bleeding the master cylinder itself first. With the engine not running you should be able to get some brakes when you pump them up.

You need to look in the dust boots of the calipers to check for fluid that hasn't made it all the way out!
Try this first tho. Get 4 brake hose clamps and clamp the hoses at each wheel. Now step on the brake pedal if it still goes to the floor you either have more bleeding to do, or the master cylinder is NG, If you have a good pedal, take the clamps off one at a time and check the pedal each time, you will find the bad spot this way! When you make it to the leaky caliper removing the hose clamp will cause the pedal to sink to the floor.

[quote:0a1696ff09="M_J_RITZEL"]there is no visible leaks, the lines have been bled and the pedal still goes to the floor, Does the pedal go to the floor with the engine not running and can you pump them up? Has the master cylinder every gone completly dry? Lets try bleeding the master cylinder itself first. With the engine not running you should be able to get some brakes when you pump them up.[/quote:0a1696ff09]

The pedal goes all the way to the foor when the engine is running and when it is off. When it is off it is harded to push down but when its turned obn it just goes down with ease. I am pretty sure the master cylinder has gone dry.

When you bled the brakes was all the air removed from the lines? I agree with merlin, I could be wrong but something is telling me that there is still air in the lines. Try bleeding each wheel again,

[quote:665f2cfa16="M_J_RITZEL"]When you bled the brakes was all the air removed from the lines? I agree with merlin, I could be wrong but something is telling me that there is still air in the lines. Try bleeding each wheel again,[/quote:665f2cfa16]

I have tried bleeding them again. No luck so far. What is the proper way of bleeding the brakes, so i know im doing it right?

bleeding the lines. do one wheel at a time. there are a couple of diferent ways people do them. get a small piece of hose. the size that fits over the cap of the bleeder valve and put it on the end. with the other end in a bottle or can with brake fluid covering the end of the tube. have someone pump up the brakes a few times until the pedal gets harder. when the pedal gets hard the person in the car keeps a steady pressure on the brake pedal. the one under the car bleediing the brakes opens the bleeder valve a little {the person in the car will feel the pedal go down, they would keep pressure on the pedal until the one bleeding the lines lets them know the valve is closed and they can release the pedal. meaning that you have closed the line. if one lets the pressure off the brake pedal before the valve is closed, it could suck air back in when the pedal is released before the bleeder valve is closed. With the end of the hose in a can with brake fluid it is less likely that air will go back in the line. bleed the lines until you don't see air bubbles comming from the covered hose in the can. When the bleeder valve is closet the person in the car pumps up the brakes again. Then they hold the brake pedal like before. continue bleeding the brake until all the air is out, after the brake is bled proceed to the next brake. Keep checking the brake fluid resevior so it does not run dry. Keep filling it each time you bleed each wheel.