Brake Pedal Soft/Spongy Feeling

[Polish Thug]

So I changed my brake pads today with some Hawk HPS pads, also while bleeding the brakes I tried to flush out as much fluid as I could and replaced it with new DOT 3 fluid from honda. So me and a friend installed the pads and bled the brakes did about 5 to 10 pumps on each caliper, refilled the fluid.. and so forth. So I get into the car start it up and the pedal has somewhat of a mushy feeling. It is really easy to push down for the first inch or two then it gets somewhat stiffer, but I can still push the brake the floor with only minimal force.

I went ahead and drove around and seated the pads but still my pedal has this mushy/soft feeling for about the first 2 inches. It felt somewhat better and more stiffer before changing the pads but it still had the soft feeling. So my question is by bleeding the brakes could we have somehow messed up the master brake cylinder? Or could it be that my 04 has close to 132k and just the brake master cylinder is wore out? The car stops way better then it did before with whatever the previous pads were on it but it still bothers me that the pedal has the soft feeling. I checked all the bleeder nipples and the brake fluid reservoir and I did not see any signs of any leaks. So if anyone could please help me out I would appreciate it.

Thanks,
Luke

[Polish Thug]

I read a thread where someone said it was necessary to bleed the abs system. Is this something I should attempt?

[chiwhitesi]

i experienced something similar to this earlier in the year and then i read on here that you need to bleed the ABS then the normal routine. Just take the car out on a gravel road and let the abs kick in a few times, bleed your breaks again starting with the closest to the MC and you should be good to go. At least that is what i did and it worked for me.

[56chevydan]

I don't know how you bled your brakes, but this is the way I do it and it has worked for me. Start on the left front (LF). I put a box end wrench on the wheel cylander brake bleeder nipple and then attach a rubber hose to that nipple that fits the brake bleeder nipple tight. The other end of the hose is submerged in clean brake fluid in a glass bottle. I have someone sit in the car and press/ depress the brake fluid on my command. I have the helper press down on the brake pedal as I slightly open the brake bleeder and allow the air bubbles and a small amount of brake fluid out into the bottle. I have the helper keep the pedal down to the floor so I can close the brake bleeder before the pedal comes up. I repeat this procedure on each wheel cylander until no more air bubbles come out when the brake bleeder is opened/closed. After each wheel cylander bleeding, tighten the brake bleeder and check your master cylander and make sure the fluid level is full. Repeat this process on each wheel cylander going LF, RF, RR, LR.

Just a word of warning, if you replaced your rear brake pads while doing this brake bleed procedure, make sure you back off your emergency brake adjustment on the rear pads so the pads aren't dragging on the rear rotors with the new thicker pads.

After all 4 wheel cylanders are bled, make sure you top off the master cylander again. Never re-introduce your used brake fluid back into your master cylander. For more info. refer to the EP3 service manual section 19-8.

[Drew1d]

56ChevyDan's process seems right to me. If it's spongier after you bled the brakes, you let air in. I'd also suggest, if you wish to change the fluid, use a turkey baster and take as much of the old fluid that you can out of the reservoir. Fill it up with new stuff, then bleed the brakes. (And throw away that turkey baster.)

[Twisted-X]

Has anybody tried one of those reverse bleeder tools? Here's a link: Reverse Bleeder Tool (http://www.brakebleeder.com/index.php?main_page=product_info&cPath=2&products_id=16)

Supposedly it works well on ABS systems because it pushes the air back out of the valves instead of trying to force it through. :shrug:

[BeaterEP]

I've got one of those cheapo vacuum pump kits from an Auto Zone that I picked up the last time I did my brakes, and it seemed to work OK. The biggest problem I had was getting a tight seal between the tubing and the bleeder screw, but it didn't seem to allow any air in to the system, just sucked extra air in to the tank.

LINK:Auto Zone Vacuum Pump Kit (http://www.autozone.com/autozone/catalog/accessories/accProductDetails.jsp?itemIdentifier=70116_0_0_&skuDescription=OEM+/+Liquidsiphoningvacuumpumpkit&brandName=OEM&displayName=Liquidsiphoningvacuumpumpkit&skuDisplayName=OEM&categoryNValue=10099999&navValue=100478&categoryDisplayName=Liquidsiphoningvacuumpumpkit&parentId=00-10&itemId=478-10&productId=70116)

[Twisted-X]

I've got one of those cheapo vacuum pump kits from an Auto Zone that I picked up the last time I did my brakes, and it seemed to work OK. The biggest problem I had was getting a tight seal between the tubing and the bleeder screw, but it didn't seem to allow any air in to the system, just sucked extra air in to the tank.

LINK:Auto Zone Vacuum Pump Kit (http://www.autozone.com/autozone/catalog/accessories/accProductDetails.jsp?itemIdentifier=70116_0_0_&skuDescription=OEM+/+Liquidsiphoningvacuumpumpkit&brandName=OEM&displayName=Liquidsiphoningvacuumpumpkit&skuDisplayName=OEM&categoryNValue=10099999&navValue=100478&categoryDisplayName=Liquidsiphoningvacuumpumpkit&parentId=00-10&itemId=478-10&productId=70116)

Stacey David (of "Gearz") suggested putting some bearing grease on the bleeder screw down by where it meets the caliper/drum and on the nipple when vacuum bleeding, might be worth a shot. I had the same problem with my mityvac bleeder, gave up and went back to 2 person way.

[Mechanic]

Luke, the soft, spongy feeling you described is a consequence of air someplace in the brake system -- in the master cylinder, a wheel cylinder/caliper, or someplace in the brake lines. Air, of course, can't be compressed in a brake system, so the pedal will continue to feel spongy until you get it out. And as you've probably discovered, there is no shortage of opinions WRT the best method to bleed a brake system.

I sold an EP3 recently, and before doing so I wanted to ensure the fluid in the MC looked clear and clean. Equally important, I wanted the brake pedal to feel as firm as possible on initial application.

What follows is how I do it. (Other methods work fine; this is mine.) First, you need to ensure you're following the correct brake-bleeding sequence for the EP3. It's LF, RF, RR and then LR.

When it comes to actually bleeding the system, many people opt for the two-man (or one man, one very bored wife) system. One person works the brake pedal and the other person bleeds the system. In the days before anti-lock braking systems (ABS) became common, that wasn't a problem. One person pumped away, then s/he pushed the pedal to the floor and held it there while the other person opened the bleeder valve on the caliper. The problem with doing that on an EP3 is that integral to the master cylinder (MC) is what I'll call the "secondary" MC "chamber" for the ABS. Pushing the pedal to the floor -- something you rarely, if ever, doing in normal brake applications -- risks pushing crud in the primary MC chamber or on the MC piston (which is common) -- into the ABS system or abrading the seal between the two chambers in the MC. If that happens, not only will the system continue to feel spongy, the MC will continue to lose pressure over time. In other words, the pedal feel will continue to deteriorate over time, and you'll end up replacing the MC. (There a whole thread describing this issue on s2ki.com, an S2000 board.)

The alternative is for the second person/bored-wife not to push the pedal all the way to the floor. This, of course, requires a delicate touch and a sophisticated brake pusher. (Some people put a block of wood under the pedal to prevent it being pushed too far.) That works, but what I prefer is gravity bleeding. It's just what it sounds like -- gravity does the bleeding while you work the levers, so to speak.

Gravity bleeding is admittedly a slow procedure. But, assuming your brake system is in otherwise good working order (i.e., the MC hasn't been compromised as discussed above), the result is a rock-hard pedal. The other benefit is that gravity bleeding is a one-man job.

The How To is simple: Open the MC and extract the fluid in the cylinder with a turkey baster. Replenish the fluid with fresh fluid. Then attach a clear plastic hose to the LF brake caliper, put the other end in some collection container (sode bottles work well), and open the bleeder valve. Fluid will s-l-o-w-l-y run out, pushed out by gravity. You'll see the fluid coming out and, typically, you'll also see bubbles of air in the fluid if there's any in that brake line or the brake caliper. (You'll also see air in the clear hose. Don't worry about that. What you're trying to remove is the air captured in the fluid.)

The important thing is not to let the MC empty completely. Just keep topping it up. You'll see it go down gradually, and you'll have plenty of time to replenish the fluid in the MC. In ten minutes or so, the brake fluid will run clear at the LF caliper. When it does, close the bleeder valve and top up the MC so you don't forget to do that before moving on to the next caliper. Some people choose a replacement brake fluid that's a different color and watch for the color change at the caliper. (E.g., Honda fluid is sort of carmel colored; ATE brake fluid is blue or red.) When you have fresh fluid in the line and the fluid is bubble-free, move to the next caliper. The rear calipers take longer to run clear -- typically 15 minutes or more. Just be sure to keep an eye on the level of the brake fluid in the MC.

Again, this is a slow brake-bleeding process, but it works great and it's incredibly simple to get right.

One footnote: You cannot tell whether the brake system is working correctly or free of air with the engine off. Pumping the brakes with the engine off bleeds pressure from the brake booster, and the pedal will feel rock hard. Again, this tells you nothing about the brake system, or whether there's air in the system. The only way to know whether the system is free of air after you've bleed it is to start the engine and apply the brakes.

In summary, done correctly, nothing (IMHO) works better than gravity bleeding, and you'll end up with a brake system completely filled with fresh fluid. I recommend it.

[BeaterEP]

Stacey David (of "Gearz") suggested putting some bearing grease on the bleeder screw down by where it meets the caliper/drum and on the nipple when vacuum bleeding, might be worth a shot. I had the same problem with my mityvac bleeder, gave up and went back to 2 person way.

Nice! Definitely worth a shot next time out. Especially since my install/maintenance buddy has moved about an hour away for work, LOL. The wife won't even touch the car when it's on stands LOL, so I've got nobody to pump my brakes!

Yeah, mechanic, I've heard good things about gravity bleeding. If the el Cheapo vacuum pump doesn't work out next time, I'll probably give that a shot. Look for PMs in the next couple of months LOL. :mbiggrin:

[rspjean]

Luke, the soft, spongy feeling you described is a consequence of air someplace in the brake system -- in the master cylinder, a wheel cylinder/caliper, or someplace in the brake lines. Air, of course, can't be compressed in a brake system, so the pedal will continue to feel spongy until you get it out. And as you've probably discovered, there is no shortage of opinions WRT the best method to bleed a brake system.

I sold an EP3 recently, and before doing so I wanted to ensure the fluid in the MC looked clear and clean. Equally important, I wanted the brake pedal to feel as firm as possible on initial application.

What follows is how I do it. (Other methods work fine; this is mine.) First, you need to ensure you're following the correct brake-bleeding sequence for the EP3. It's LF, RF, RR and then LR.

When it comes to actually bleeding the system, many people opt for the two-man (or one man, one very bored wife) system. One person works the brake pedal and the other person bleeds the system. In the days before anti-lock braking systems (ABS) became common, that wasn't a problem. One person pumped away, then s/he pushed the pedal to the floor and held it there while the other person opened the bleeder valve on the caliper. The problem with doing that on an EP3 is that integral to the master cylinder (MC) is what I'll call the "secondary" MC "chamber" for the ABS. Pushing the pedal to the floor -- something you rarely, if ever, doing in normal brake applications -- risks pushing crud in the primary MC chamber or on the MC piston (which is common) -- into the ABS system or abrading the seal between the two chambers in the MC. If that happens, not only will the system continue to feel spongy, the MC will continue to lose pressure over time. In other words, the pedal feel will continue to deteriorate over time, and you'll end up replacing the MC. (There a whole thread describing this issue on s2ki.com, an S2000 board.)

The alternative is for the second person/bored-wife not to push the pedal all the way to the floor. This, of course, requires a delicate touch and a sophisticated brake pusher. (Some people put a block of wood under the pedal to prevent it being pushed too far.) That works, but what I prefer is gravity bleeding. It's just what it sounds like -- gravity does the bleeding while you work the levers, so to speak.

Gravity bleeding is admittedly a slow procedure. But, assuming your brake system is in otherwise good working order (i.e., the MC hasn't been compromised as discussed above), the result is a rock-hard pedal. The other benefit is that gravity bleeding is a one-man job.

The How To is simple: Open the MC and extract the fluid in the cylinder with a turkey baster. Replenish the fluid with fresh fluid. Then attach a clear plastic hose to the LF brake caliper, put the other end in some collection container (sode bottles work well), and open the bleeder valve. Fluid will s-l-o-w-l-y run out, pushed out by gravity. You'll see the fluid coming out and, typically, you'll also see bubbles of air in the fluid if there's any in that brake line or the brake caliper. (You'll also see air in the clear hose. Don't worry about that. What you're trying to remove is the air captured in the fluid.)

The important thing is not to let the MC empty completely. Just keep topping it up. You'll see it go down gradually, and you'll have plenty of time to replenish the fluid in the MC. In ten minutes or so, the brake fluid will run clear at the LF caliper. When it does, close the bleeder valve and top up the MC so you don't forget to do that before moving on to the next caliper. Some people choose a replacement brake fluid that's a different color and watch for the color change at the caliper. (E.g., Honda fluid is sort of carmel colored; ATE brake fluid is blue or red.) When you have fresh fluid in the line and the fluid is bubble-free, move to the next caliper. The rear calipers take longer to run clear -- typically 15 minutes or more. Just be sure to keep an eye on the level of the brake fluid in the MC.

Again, this is a slow brake-bleeding process, but it works great and it's incredibly simple to get right.

One footnote: You cannot tell whether the brake system is working correctly or free of air with the engine off. Pumping the brakes with the engine off bleeds pressure from the brake booster, and the pedal will feel rock hard. Again, this tells you nothing about the brake system, or whether there's air in the system. The only way to know whether the system is free of air after you've bleed it is to start the engine and apply the brakes.

In summary, done correctly, nothing (IMHO) works better than gravity bleeding, and you'll end up with a brake system completely filled with fresh fluid. I recommend it.

i know this is an old post but i just wanna say for anyone who has this problem this worked perfectly for me. thank you.