How serious a problem is air in your brake lines? + brake questions

92 accord 4 door lx. about a month ago my brakes broke and i just fixed them this week. I replaced the left driver hose, and brake pipe(that leads to the proportionality valve under the resovoir). because I stripped the nut connecting the pipe to hose. Then I discovered my caliper was also broken so I replaced both fronts. Btw, I replaced those calipers which were originally akebono(sedan) with Nissan(coupe) calipers. Anyone know if theres any significant difference between the two? besides the different bolts, different sized bleeder valves and different shaped pads? performance wise? I ordered rebuilt akebono calipers from the local autozone, but they gave me nissan.

Now, I seem to have a somewhat minor amount of air in my brake lines. I’ve bled them twice, and frankly can not see anything i’m doing wrong. My car does stop, but i’ve compared it side to side with a 91 accord and my pedal doesn’t seem as firm as hers. Bear in mind, my car is a salvage vehicle however.

My brake pedal does not sink. So I don’t think theres any backflow involving a broken master cylinder. However I notice that sometimes my pedal doesn’t seem quite consistant. Sometimes I think I notice that it depresses further before the brakes engage in force. This is usually after tests where I brake quickly from 70 to 20ish(I love long empty roads) does the air in brake lines heat up and thus require more pressure to compress?

hrm what else… with the car on, I can depress the pedal all the way to the floor. Is that normal?(my friend’ car does it too, but it’s harder. I haven’t discounted the possibility that her brakes could need some repair as well…)

Should my brakes be powerful enough to skid my car? I thought I was able to do that before, but I didn’t seem to notice any skidding action when I was testing it today.

Does anyone know how to check if my brakes are dragging?

How much air is too much?

any advise?

In order:
[li]There is no such thing as a minor amount of air in a brake system. Any at all is two much.[/li][li]Absolutly not. The pedal should not go to the floor. Air in the brake lines would cause this.[/li][li]See #1 above[/li][li]Yes. If brakes are improperly done, people can die. Maybe you, maybe a kid in a crosswalk. From where I am at, it would appear that you do not know what you are doing with the brakes on this car. I would strongly urge you to get a competent mechanic to do the necessary repairs with the proper parts. The life you save might be mine.[/li][/list=1]

What Rick said. And…

Btw, I replaced those calipers which were originally akebono(sedan) with Nissan(coupe) calipers. Anyone know if theres any significant difference between the two? besides the different bolts, different sized bleeder valves and different shaped pads? performance wise?
Besides those features? No, I don’t know if there are still other significant differences. But different shaped pads is significant. I fix cars professionally and I would not use different shaped pads, nor would I install a replacement brake part where I had to wonder if it would perform adequately.

I ordered rebuilt akebono calipers from the local autozone, but they gave me nissan.
Just because they provided the wrong parts doesn’t mean you have to use the wrong parts. And there are other parts sources than the one you used – sometimes getting the right part in good quality is worth more than saving a buck.

Now, I seem to have a somewhat minor amount of air in my brake lines. I’ve bled them twice, and frankly can not see anything i’m doing wrong.
If you’ve gotten air out of the lines when bleeding, then I would guess you either haven’t gotten all of it out yet, or there’s a leak that’s sucking air in. Without watching over your shoulder, I can’t see if or what you might be doing wrong. You’re wise to seek help, but I don’t think we can offer much in cyberspace that can safely and thoroughly address your situation.

However I notice that sometimes my pedal doesn’t seem quite consistant. Sometimes I think I notice that it depresses further before the brakes engage in force.

This symptom is rather scary.

…with the car on, I can depress the pedal all the way to the floor. Is that normal?
No. A brake pedal should never go to the floor. I do mean to the floor, as in part of the pedal physically touches the floor. A pedal going that low indicates air in the system, internal leakage (usually a master cylinder), or incorrect components, like, say, the wrong calipers for the vehicle.

Should my brakes be powerful enough to skid my car?
Generally, yes, but actual skidding depends on the tire-to-road interface.

Does anyone know how to check if my brakes are dragging?
Raise the wheel off the ground and spin it (parking brake off, tranny in neutral). Drum brake should have virtually no resistance, disc brake should have light drag. There will also be some resistance turning the drive axle. You should be able to grab a front tire and give it a hearty enough spin that it will continue to rotate some (maybe not even a full revolution, but some) after you let it go.

Midas offers “free” brake inspections.
Have them (or like competitor) go through the system and give it a good safety check. Ask them to bleed the system as long as they have it in the shop. Shouldn`t cost too much. Sounds like you did most of the costly work already.


You bled it twice. The master cylider is probably letting air in. Take everybody’s advice. You are scaring me. Brakes, as it turns out, can be vitally important to your safety, as well as others. Whoda thunk it!

I’ve been working on brakes on my personal vehicles for over 20 years now. In fact, I just replaced 12 feet of brake line in my truck over the weekend. (Fun job.) So here are a few words of wisdom:

My opinion only – Don’t go to Midas. Or any of those other chains. They’re rip off artists. Again, my opinion only. Instead, find a reputable, independent, and ASE-certified mechanic to look at you brakes if you feel you’re unqualified to work on them yourself.

Air in the brake line is Bad[sup]TM[/sup]. This is because air easily compresses. (Brake fluid is designed to compress a only a very slight amount.)

Are you bleeding the brakes correctly? Here’s the procedure I use, which is based on articles from Click & Clack, etc.:

  1. Slip a 12-pt. closed end wrench over the bleeder valve/screw/nipple (or whatever you want to call it).
  2. Connect a hose to the bleeder valve. The hose should be long enough to reach a plastic cup or jar. The hose should also be transparent so you can see air bubbles in it.
  3. Fill the reservoir in the master cylinder with brake fluid.
  4. Set the cover back on the master cylinder. There is no need to clamp it secure. But make sure it’s on there, else fluid could squirt out of the reservoir and make a mess.
  5. Have someone get in the driver’s seat and pump the brakes 7 or 8 times. On the last “in” stroke they should apply static pressure to the brake pedal. (In, out, in, out, in, out, in, out, in, out, in… hold and maintain steady pressure.)
  6. Tell the person in the driver’s seat (who is maintaining pressure on the brake pedal) that the pedal will soon start going to the floor. Tell this person to maintain pressure and not let up on the pedal until you say so.
  7. While this person is maintaining pressure on the brake pedal, start opening the bleeder valve by turning it CCW.
  8. Stop turning the bleeder valve as soon as you see fluid and/or air coming out.
  9. Yell to the person in the driver’s seat, “Let me know when the pedal won’t go any further.”
  10. When this person says, “the pedal won’t go in any further,” or “the pedal has gone to the floor,” close the bleeder valve by tightening it CW.
  11. Repeat steps 5 through 10 one or two more times.
  12. Add brake fluid to the reservoir in the master cylinder. Never let the reservoir run dry, else you’ll introduce a big air bubble and you’ll have lost all the progress you’ve made.

Keep bleeding the brakes until you no longer see air bubbles. But keep in mind that, if you do not see air bubbles in the transparent hose, it doesn’t necessarily mean there are no bubbles somewhere in the brake line. So you should continuing bleeding them over and over until you believe you have purged all of the old fluid out of the line.

You Dirty Liar! Thats MY opinion, too! Don’t try to go “Hogging” it! :smiley:

Ever wonder how they can offer “free Lifetime Warranty”? Easy! They charge you 4 times what the job is worth the first time and hope you only come back 2 more times!

She told me she loved me like a brother. She was from Arkansas, hence the Joy!

In general I would agree with you and gatopescado on the quality of, and cost of Midas repairs, but compared to the circus of horrors described in the OP, Midas is God’s gift to auto repair.

[Minor nitpick] Brake fluid does not compress to any measurable degree [/MNP]

There is simply no way of committing overkill with this point, even though three posters have said it before. Dont. Go. To. Midas.

Altho others have suggested avoiding Midas and similar shops, any one of them would be infinitely better than doing nothing. If you decide to do nothing, can you at least tell us where you live in California, so other Californians can try to avoid you?

"“free Lifetime Warranty”?

I think that only covers the pads, not the labor.

Absolutely correct. It’s like the lifetime warranty on a muffler. Sure, they won’t charge you for the muffler itself, but they’ll charge you for all the other pieces (pipes, resonators, hangers, you name it), and about 3 hours of labor. For a brake job, the pads are the cheap part, so the warranty ain’t worth much!

My pedal goes to the floor, but after a significant amount of pressure on my part(not driving, just sitting there pumping it with the engine on). i.e it gets harder the farther I press… I just tested my friends 91 and another friend’s 89 accord. They both do the same thing. – on a side note, could I ask people to test their cars? When I turn my car on I can push my brake pedal all the way to the floor, albeit with significant resistance. With it off it moves no more then 1 cm.

As far as I can tell Honda simply sourced 2 different companies for the calipers, but i come here for a more definitive answer. Everything fits perfectly fine. the pads are different shapes, but I got new ones for the nissan calipers. My haynes manual even mentions the nissan caliper type, and says they only have different bolt-length types and torque specs.

I was thinking just this actually. let me run a few ideas past you. as far as I can tell before my car broke down, there was no problem with air leakage into my car. So i’m guessing if there is a leak, it’s either at the bleeder valve, banjo bolt, brake hose to brake pipe and brake pipe to proportionality valve connections – all the places i’ve had unscrewed. (I had a shop install my brake pipe and brake hose.) Is there any way of testing for a leak at those positions? or should I just torque them down some more?

also… is there any sort of “grime gaurd” such as with engine oil? My old brake fluid was NASTY, and i’ve since completely flushed it out with valvoline synthetic.

How much would a shop charge me to bleed/check for leaks?

I agree, but i haven’t noticed it since, nor has anyone else who has helped me test-drive my car. I think it was in my head.

My car has ecasta 712 kumho tires. Generally held in high regard, as they’re performance tires. I was however driving on a pretty crappy backwater road. I didn’t skid, but I didn’t really slam my brakes either.

the better the tires grip, the harder to skid right?

AHHHH, tranny in neutral! thanks! i’ll try this later today.

I so completely agree. I had my car towed to big O tires. they wanted over 600 dollars for my repair. Having bought the parts myself, it appears 450 of that was labor.

I don’t have the symptoms of a broken master cylinder(sinking pedal).Unless you’re driving around at 3 am in davis california on the backwater farm roads, You probably have nothing to worry about.

I am using your described method of bleeding brakes.

“The pedal should not go to the floor. Air in the brake lines would cause this.”

Antilock brakes go pretty low & thats normal.

“Will I notice anything when the ABS is working?
In many vehicles, drivers may experience a rapid pulsation of the brake pedal–almost as if the brakes are pushing back at you. Sometimes the pedal could suddenly drop. Also, the valves in the ABS controller may make a noise that sounds like grinding or buzzing. In some cars you may feel a slight vibration–this means the ABS is working. It is important NOT to take your foot off the brake pedal when you hear noise or feel pulsations, but instead continue to apply firm pressure.”

The fact that the pedal does not move much with the engine off is pretty meaningless. It is normal for the brake pedal to be high and hard with the engine off. The pedal going to the floor with the engine on is NOT normal. As far as the pedal getting harder the harder you press, again this is normal even if there is air in the system.

Except for the fact that this is not how Japanese carmakers source parts. Usually (and by this I mean every Japanese part I ever looked up when I was selling auto parts) the Japanese car makers only change part suppliers with a production date break (all the cars built until June have one part, the other is for cars built in July and later) or When there is a specification difference between the models in your case there is somewhere around a 200 lb difference listed between the coupe and the sedan. This could result in smaller brakes on the coupe. Bottom line is you installed the wrong part on the car. No matter how you want to try and weasel around it, you installed a part that the Honda engineers determined was not to be used on a sedan. Now there can be two reasons for this. 1) You know more about the car than the guys that designed it. Or 2) You did not know enough to understand that you made a mistake. Just because a part can be bolted to a car does not mean it should be bolted to the car.

Well guessing that any air leak into the system is from something that was disassembled is in fact an excellent idea. However bleeding the brakes may have caused a master cylinder that was almost bad to fail (clear all the crud out from in front of the seals, and they start to leak) Also if you had a shop install the hose and pipe, why didn’t you have them bleed the brakes?
As far as the torque on the fitting goes, they need to be tight. Honda probably has some torque specifications for most if not all of these fittings. If the fitting are torqued to specification, more torque won’t help and may in fact due damage by either breaking things, or distorting fluid couplings so that they start to leak. In general inexperienced mechanics (and you are square in the middle of this group) either leave things way too loose or get them so tight they scream.


OG please tell me you used synthetic brake fluid not synthetic motor oil :smiley: I’m not sure just what you are asking here. Is there something you can flush the system with? Not unless you disassemble the entire system. You can pump brake fluid through the entire system until the fluid runs clear. If you are asking if there is an additive you can add to brake fluid to reduce / prevent sludge the answer is NO. DO NOT PUT ANYTHING EXCEPT BRAKE FLUID IN THE MASTER CYLINDER. Memorize this. Inscribe in on your forehead if necessary.


Prices vary from shop to shop, probably ½ to 1½ hour at the going labor rate

:confused: :confused: Good tires would make skidding harder, rough / crappy roads would make skidding easier. Where I am totally lost is the statement that you really did not slam on the brakes. If you were trying to see if the car could / would skid I would think that you would slam the brakes on as hard as your leg could push. :confused: This still has me confused

A very scary comment

There are a couple of other significant differences between the $150 you have invested so far and the $600 a pro wanted. For $600 you get the correct parts for the car, and the car is repaired correctly and probably has a warranty. So far you are out $150, incorrect parts are installed on the car and the car is still broken. I fail to see the bargain here.

WTF??? From the very first line of your post **

This goes along with the comments about my brakes won’t skid, and I wasn’t really trying to skid the car. These comments sound to me like you are getting defensive and trying to cover your ass. Look I don’t care if the pedal goes to the floor or not, but if you want advice pick a goddamn symptom and stick to it. OK? Don’t tell me that the pedal sinks and twenty lines later tell me it doesn’t.


Swell I’m safe but my daughter’s boyfriend is in mortal danger, wonderful, just wonderful. Also in case you have not noticed Davis has more bicycles per capita than any other city in the US. Bicycles loose when hit by cars.

Dude, speaking as someone who has worked in the automotive business for probably longer than you have been alive, let me give you some advice.
Put down the wrench and step away from the car. Brakes are not the system that you want to learn about auto mechanics on.

In a word, no. When the ABS system is not active the pedal travels no further than a non ABS system. When the ABS activates to prevent a skid the pedal may drop or pulsate. After the danger of skiding is past the pedal returns to normal height and feel.

Also for your general fund of information not all 92 Accords had ABS (per intellichoice)

Maybe just me, but did anyone else get the impression that the original poster mentioned somewhere along the line changing to synthetic brake fluid?

I seem to vaguely remember that you have to have a pristine brake system to use synthetic ---------tends to leak (in and out) much more easily than DOT3.

Rick has, as usual, done a nice job of answering several questions. I just want to clear up one point.

Do the brake pedals in the three cars described actually go TO THE FLOOR? Not to a “stop,” where it feels like the pedal has hit something solid, but to the FLOOR, where if you put a single sheet of paper under the pedal, it would be tightly pinned between the pedal arm and the carpet. If those pedals are actually TOUCHING THE FLOOR, then something is wrong. Brake pedals don’t normally hit the floor on my 92 Accord, a customer’s 95 Accord I had today, nor any car I can recall in 30 years of fixing cars.

Since the pedal only goes down 1 cm without the vacuum assist, and the pedal doesn’t sink, I rather doubt the pedal is hitting the floor with the engine running. However, it’s significant if the pedal does indeed go that low.

I thought the same thing. I wondered about it enough to drive down to the local Pep boys and pulled a bottle of the fluid he said he used. The contents on the bottle say that it is the same contents that the cheap stuff. It is not silcone. (Great marketing ploy by Valvoline BTW)

If you’re in Davis, you’re WAY too close to me for comfort. Hire a pro to do this work!