anibis

Ok, so I have a friend who drives a '2000 Civic. He bought this car at an auction already rigged (modded) up. The brakes are slightly dragging. I can turn the wheel by hand, but there is more resistance than there should be. There is NO PLAY in the brake pedal, when you push the pedal its hard from the get go. The same kinda feeling you get when there's air in the system, only there's not. Brakes work fine otherwise. I've already checked the brake light switch and it's where it should be.

I know the MC pushrod should never need adjusted. I'm just wondering if the fool who owned this car before decided to adjust it himself. The rear brakes are totally gone, and the car only has 112k on it. I've never known a Civic to go through rear shoes that quick....makes me think the brakes have been dragging for some time.

Do I need a special tool to loosen the locknut? I couldn't find any info adjusting the pushrod for this generation.

ezone

Is the rubber seal on the brake fluid cap all squishy and distorted?
Dip a finger in the brake fluid. Does it feel oily?

anibis

I had a chance to work on the car today.

Rubber seal looks fine, brake fluid feels oily, looks good.

When I got in the car and tried to apply the brakes the pedal went to the floor. I was looking around the front tires and saw a puddle of fluid under the LF. I pulled the tire off to find the caliper was leaking fluid badly. Apparently the owner had driven the car with the brakes grinding for quite awhile, and ruined the caliper by doing so. He said the pedal had been going to the floor for several days. There was absolutely NO inner pad, I mean it was grinding on the piston. There was a sliver of outer pad left. The right side still had a little inner & outer pad left, and the caliper looked good.

I replaced pads+rotors and 1 caliper. Bled the front brakes till I saw no air, then a little more. There are brakes now, but the pedal travel is all over the place. Sometimes it's normalish. Other times it goes to the floor. If I pump it a bunch of times the pedal comes back.

So now I'm thinking, by taking the brake pedal to the floor so many times, the brake MC is ruined too? What does everyone think?

I looked at the lock nut for the MC pushrod, it's all chewed up, like someone took vice grips to it. Looks like the "rigger" who owned the car before messed with it. If I replace the MC, will I still need to re-adjust the pushrod? How do I go about that without using a trial and error method?

Oh yeah and while it was leaking, there was fluid visible in the reservoir. The brake light was not on when I started the car. I don't believe the level got low enough to for air to get in the MC.

GolNat

iTrader: (7)

I wonder since it was an auction car if the odometer is correct.

Is it losing brake fluid?

anibis

No it's not losing any fluid, no leaks that i could find either.

You could be right about the odometer, a 14 year old car with 112k is pretty rare. The car is pretty beat up too.

ezone

Brake fluid should never feel oily.


Get some fresh clean brake fluid, dip your finger in it, pull your finger out.
See what it feels like.
Feels dry? Warms your finger?

Now compare the feel to the fluid in your reservoir.






Next check:
Extract some "brake" fluid from your reservoir.
Pour it into a clear vial of water. (Roughly 50/50 is fine.)
Brake fluid will dissolve in water. Oil will not.
What happens?

anibis

It didn't feel like motor oil oily. I just dipped my fingers in the bottle of prestone dot3 I bought today and it feels the same - not like motor oil, but makes my fingers slick just from having fluid on them. That's what I meant by feeling oily. Once I wiped my hands with a cloth it's gone, unlike oil which leaves a slick residue.

My buddy got this car a few months ago. When I was checking it out I noticed the brakes were dragging. I bled all 4 corners using a brand new 1qt bottle. As for the fluid that was in the car before, who knows, it's long gone now. I don't remember it looking bad or being oily though. Bleeding the brakes didn't effect the dragging issue. I didn't want to spend hours trying to figure out what would cause all 4 corners to drag, so I just told him to take it to a shop and have them check it out. Of course he didn't.

When I examined the pushrod lock nut today I can tell it's been messed with. The car is (cheaply) modded to hell. That makes me think the previous owner liked to tinker with things. Maybe he was trying to get the brakes to be more responsive, I don't know. There is no reason for that lock nut to be busted loose, so it should look brand new, which it does not.

Before the caliper exploded the pedal was fine, just firm and had no play. Now it's all over, sometimes going to the floor, sometimes about half way down. If I push on the pedal hard it slowly goes to the floor, and I have to pump the brakes to get it back. Just trying to figure out what else has gone wrong. A pedal going to the floor usually means a leak, air in the system, or a bad master cylinder, right? I guess you could add not using brake fluid to that list, but I don't believe that is the issue.

ezone

NOW you're getting somewhere.
Damn, nobody ever messes with that, I wonder why someone would?

There must be free play in that pedal pushrod, and there must be free play in the rod between the booster and master.
Nope. That's the most common causes, but not the only possible causes.

ezone

If the master piston can't return to the fully released position, the compensation port(s) aren't uncovered to release fluid pressure into the reservoir as the fluid expands and contracts. This creates a (semi-)sealed circuit, and the heat in the calipers and wheel cylinders causes fluid to expand, causing the brakes to be applied, causing more heat, causing even harder brake application, causing even more heat, etc. Fluid boils, pedal goes to the floor. Brakes get eaten up, rotors and drums warp and turn red, gas mileage goes to hell.
Some people can't figure out something is wrong and keep pushing the gas pedal.

Same thing can happen when petroleum products are introduced into the brake system and cause the rubber seals to swell up. Swollen seals block off the compensation ports and the above scenario happens.


While the compensation ports are blocked and the fluid cools, the caliper pistons can be literally pulled inward under a vacuum and cause excess pedal travel the next time you push it.

Rapidly pumping the pedal might cause the ports to get uncovered briefly so the system can equalize and work again temporarily.



Now that I think about it, even a simple misadjusted brake light switch could cause the same thing to happen.

anibis

I've already checked this, as stated in my initial post. It was one of the first things I suspected.

I thought it was odd that you didn't react when I said I could tell the locknut had been messed with in my first post today. That's why I brought it up again. I never thought of checking it before because I've never known/read about anyone messing with it. You can tell he didn't have the "special" locknut tool, it looks like he used vice grips or something. The notches of the star nut look okay, its just scraped all to hell.

It would make sense if the pedal travel changed with heat, but it doesn't. It was all over the place from the get go with the brakes dead cold. If I leave my foot on the brake with moderate pressure, it sinks to the floor. If I push hard, it goes right to the floor. Also, before, the dragging never got worse, it was always the same. Both with hot & cold brakes. I thought about heat and did a hot/cold test when trying to determine what was causing the problem a few months ago.

I think the guy who owned the car knew enough to mess things up. I doubt he was a total idiot who would use oil instead of brake fluid. Just a guess though, who really knows.

ezone

I skimmed right past that part the first time, I guess. I can't read.
EDIT: Wow, I really didn't read parts of your posts.

Maybe you have multiple issues for all I know. You have described a pretty weird combination of observations.

Stick a master on it, but do the measurements/adjustments for the booster pushrod AND set up the pedal pushrod correctly?
JizzyLube can do that part. Oil must go in everything.

anibis

There is no doubt in my mind that multiple issues are going on here, just what they are is up in the air.

This is what I'm thinking:

The brakes are dragging because the pushrod was messed with, this was an issue from the day my buddy bought the car. Back then, the pedal felt too firm, had no play, but the brakes worked fine. Never had a problem with the pedal going to the floor until AFTER he ruined the caliper. I fix the caliper, brakes kinda come back, but pedal travel is all over.

By taking the pedal to the floor (and there is no doubt he was SLAMMING it into the floor because the car wouldn't stop), he ruins the MC as well.

I read this somewhere. Since the MC piston never goes past a certain point, over time buildup will occur at the stopping point. Then, the pedal goes to the floor and the piston seals get pushed through the buildup and ruins them. I'm sure the pedal went past that point over and over again. I have only read this, never experienced it.

It's either that, or pushing the pedal with all his might did something else to the MC.

Is this plausible? Any thoughts?

ezone

I wrote that the other day.It happens far more often than most realize or care to admit.

It's the entire reason one dealer I used to work at changed their brake fluid service procedures. Too many were getting ruined by the standard "pump the pedal" method.


No. Seriously. Think how many panic stop failures there would be if this happened regularly. Lawsuit City



What I can't figure out is WHY anyone would ever think they need to touch the pedal pushrod adjustment in the first place. Someone had to go to a LOT of work to get under there to do it.
Aftermarket MC already?
Attempt at some adjustment for some other (yet undiscovered) problem?
Booster got replaced?
What????

anibis

I had read about the buildup issue a year or two ago on another site when I was in my car phase. I wasn't sure if it actually happened all that often, I had never read a post about it on here.

Slamming on the brakes is no issue on a healthy system where the pedal doesn't go past half way. I was thinking since the pedal was on the floor, and he was pushing with all his might, maybe the piston was being forced into the end of the MC. It was probably due to the buildup though.

I still use the pump method (don't have the tools to do it any other way), I just put a piece of wood under the brake pedal so it won't go very far. It takes a bit longer to bleed, but it prevents the piston from moving past that stop point.

I have no clue why he decided to adjust the pushrod. The MC appears to be original, not sure about the booster. It's obvious from looking at the car he liked to tinker. So, whatever the reason, he thought it was a good idea.

I'm gonna swap out the MC and go from there. From what I read, I have to break the locknut loose, then turn the pushrod clockwise to allow more play. Not sure how to go about measuring everything though. I may just tell him to take it to Honda and have them adjust it.