Stop here! Let's talk about brakes

prelude884ws

oops eheh yah that might be the problem. i'll get back to you on that one.

bpeebles

Oftentimes, when an old caliper is squeezed back to install new pads, it will start to "stick".... especailly if you have not been replacing brakeFluid every 2-3 years.

This is because when you sqeeze back a caliper, the surfaces which USED to be sitting in old brakeFluid are now expected to be shiny-clean so the piston will slide easilly.

The reason all cars should have brakeFluid replaced every 2-3 years is to purge out any moisture that has accumulated in the system. If not replaced, then raw water droplets will migrate to the lowest part of the brake-system (the calipers!) and cause internal rusting.

dms11

This has happened about 4 times in the last two months. Problems starts less than 10 miles into the drive. Vehicle feels like its pulling a ton of weight, RPM's rev up, brake pedal is hard. Turns out, its the front brakes locking. Very hot, smell of burn. Pull over on the road for about 20 minutes, continue driving and have driven as long as 1 1/2 hours w/o problems. No lights come on to signal any problems. Have taken in for service, they are just guessing. Replaced brake fluid, lines are good, replaced brakes. Still happening. Anyone know the problem/fix? Would like to eliminate the guessing ($$$).

kiawah

I would suspect your front calipers are bad. See previous writeups and posts about how the calipers go bad with moisture and internal binding of the piston.

There is a chance that it's another problem, but most commonly it's the calipers...and the parts are relatively cheap. I usually just replace them on every 2nd brake pad change as a normal maintenance item, just to avoid problems.

There are no return springs in disc brakes, the pistons just 'float' back when hydraulic pressure is released. So it doesn't take much crud or rusting behind the piston to bind the piston, preventing it from releasing completely.

imidazol97

I agree with Kiawah on this one. Replacing the calipers with rebuilt, with the slides free and lubed, may be the answer. Some rebuilt are pretty expensive, but fronts for a 98 leSabre were $30 at Advanced. Shop online at their sites to see local prices.

The odd thing is both sides doing it equally. Possibly the calipers both are doing the same thing, but I would do some asking at a dealership if there's something gone wrong with the ABS unit, e.g. The calipers rely on the seal around the piston flexing when the pistons are pushed out and then pulling back slightly to give a little play when the brakes go off. And the bumping of the wheels moves the parts back in. Aged, heated seals may be bad, especially now that everything has run exra hot from dragging. Even if the calipers weren't bad before, in my opinion they are now, so the best test would be replacement.

bolivar

Are both fronts actually dragging? If so, I would think it is something in the 'fluid management' circuits. The ABS pump, the computer/sensors that drive it (but this should sit a check engine light?), do cars still have a 'proportioning valve' with ABS?

If only one brake drags, the small rubber hose at the caliper could also be collapsing internally.

If you go to the expense of replaceing those front rotors, I sure would add the extra expense of a couple of rubber hoses. If the brakes have dragged much at all, the pads might need replaced again.

You need a brake/front end alignment shop that sees a lot of cars and knows what they are doing. Whereever you took it to should have been able to successfully repair it. I'm not sure I would trust them for further repairs. If only one side was dragging, I might consider a complete rebuild - hose, caliper, pads on both fronts.

I just went to the OReilly's web site - a rebuilt caliper, with pads, is $78 per side. A new caliper, with pads, is $97 per side. So, at least here, a caliper comes with new pads.

jeffyscott

In our 1997 Windstar the brakes pulsate when coming to a normal stop. It happens just at the end as the car is going from maybe 5 mph to 0. Prior to the very end of the stop the pedal feels normal.

It feels sort of like abs kicking in, only a lighter/milder pulsation than I am used to feeling from abs and these are not stops where it is anywhere close to needing abs.

Any ideas?

bpeebles

If BOTH fronts are dragging and the pedal feels "hard" then suspect the vacuum brake-booster. (I would bet the rear brakes are dragging a bit also.)

A common way for a brake-booster to fail is when the internal valve leaks vacuum. This will tend to 'pull' the brake pedal twards the floor and apply the brakes while you are driving.

Somtimes the internal valve can be cleaned... other times the entire booster has to be replaced.

bolivar

Classic indication of warped rotor/s. You need new rotors, or if the thickness will support it, having the rotors 'turned', which mills down the surface until they are 'correct'.

bolivar

Hummmm.... I didn't know a vacumn booster leak could self-engage the brakes. Nice to know.

I do know, for a leak, let the car idle in park. Push on the brake. In many cases you will be able to hear a 'whoooose' from the leak. Also, the idle speed should significantly slow down, as the leak lets a huge amount of air into the intake, which causes a lean air/fuel mix and drops the idle.

imidazol97

When the brake pedal is depressed, air in allowed into the one side of the diaphragm. That air entering makes a whoosh sound that can be heard in the passenger compartment. That is normal.

There may be a different or continuing whoosh that indicates a leak.

jeffyscott

I would have thought warped rotors would be noticable prior to the very end of the stop, am I wrong about that?

BTW, what do you think about this claim that warpage is a myth and the symptoms of it are actually due to "friction pad material transferred unevenly to the surface of the disc"?

I found our Ford dealer currently has a coupon for a free brake check, so I will see what they say on Monday. They did all four brakes about 1.5 years/15K mi ago.

kiawah

Warpage is not a myth, there are tools to measure it....like a micrometer on an arm that rests up againt the rotor. As you rotate the rotor slowly, you can see how much the rotor is warped. An analogy might be a ceiling fan, with one of the blade mounts bent down. Four of the blades are measured at 8" from the ceiling, one of the blades is 9" from the ceiling.

You feel the warpage the most the slowest the slower you get. Back to the analogy, if the ceiling fan is spinning slowly, you can see the blade that is bent lower. If you turn on the fan real fast, you can't distinguish the blade that is out....it just looks like the whole fan blade pack is wider.

Anytime I've had warped rotors I could feel them when putting on the brakes to slow starting at about 30mph down to 5. Having had (and personally replaced) a number of warped rotors over the years in our vehicles....warped rotors are definitely NOT a myth. The last were a set on our heavily laden Suburban that we had taken thru the mountains and overheated the rotors on some long downgrades.

bpeebles

I have personally seen several types a brake issues which cause vibration.

1) rotor warpage. (can often be felt in the steeringwheel too)
2) pad-material transfer to the rotors.
3) excessive rusting of the rotors.

Also bad wheelbearings can cause a kind of pulsating feeling during braking too.

wtd44

Another assessment worth making is to do an informal cost analysis projection. Forget the paper, pen, calculator, etc., :P and just consider the age of the brake rotors and pads, the number of miles they have been on the vehicle, etc., as you decide whether to consider resurfacing rotors versus replacing them. Short lived rotors are good candidates for upgrading. Better quality pads may last longer, etc. At this point, I am subscribing to the philosophy that if a rotor truly needs machining, it is far better to replace it and the pads at the same time. I also would do the same repairs to both sides of the front together, and both sides of the rear together. That is, I would not run new brake parts on just one side of either the front or rear.

bpeebles

I agree with you... I reciently replaced the rotors/pads on my wifes car. (all 4 wheels) The pads were still good but the rotors were badly rusted. (Vermont winters!)

With over 90,000 miles on the originals, the cost of $300 for the new parts was worth it.... knowing I will get another 90,000 miles on it before I need to do it again.

I orderd REAL German-made parts for my wifes VW.... no cheepo China or Mexico parts for my cars. Experience has shown me that el-cheepo rotors will rust/warp very quickly.

wtd44

Here in Colorado, warpage is a problem, due often to mountain driving. We destroyed a pair of original front rotors on a 2004 Jeep GC in less than 24 K miles, and solved the problem with high quality NAPA replacements. I traded off the car at 60K, but only because that's my modus operandi.

srs_49

Have you seen this paper (about rotor "warping")?

http://www.stoptech.com/tech_info/wp_warped_brakedisk.shtml

jeffyscott

With regard to my pulsating brakes, which I only feel pulsating at the very end of stops (from 5 or 10 mph to 0), the dealer said I should replace rotors and when doing rotors should also do pads even though there is plenty of pad left. But did not seem that this was related to the pulsating that I feel as they also said that was probably a malfunctioning abs sensor, though they also thought it odd that the abs light was not on. Verifying this was not part of the free brake check, they wanted about $80 diagnostic and said if it were one sensor it would be about another $170. I'd probably have gone for that if they hadn't also come up with the new rotors idea.

I am going to get a second opionion next month when I get an oil change. I don't think I need to do the rotors as the brakes seem fine other than the pulsating at the end. I did a couple hard stops and they stop the vehicle smoothly without any apparent problems no "warped" rotor feel just the pulsating issue below 10 mph. I think the rotors probably looked bad just from lack of use...the vehicle has been idle a lot of the time the last few years and has only 20,000 miles on in the 2.5 years since the brakes were done. The first two sets of front brakes had each gone about 50,000 miles.

wtd44

I suspect we refer to brake pulsing as warpage simply because our "mind's eye" conjures up the image of what the condition makes us think might be the cause. That is, our imaginations tell us that a rotor with bulges in it would make the pulsing brake feeling when the assumed bulges attempt to spread the clamping pads apart. One might more correctly say, "My brakes pulse as though the rotor has thicker and thinner places rotating into contact alternately with the evenly held pad spacing, and sometimes I can feel it in my foot." At this point in time, we all seem to understand what others mean when they tell us they have warped rotors, even though it is likely an inaccurate use of terminology.
What we need now is technology that abolishes the problem altogether! :shades:

wlbrown9

The Jeep GC had (IMHO) defective rotors and calipers. '99 & 00' Jeep GC rotors 'warped'. D/C refused to fix after 17K miles on the 00'. I paid less than $100 for generic rotors from AutoZone that did not warp from there until we got rid of it at 70K miles. The only time they warpped was when the defective rotors did not release and the brakes heated way up, burned finger just testing to see if there was heat buildup. When they cooled down, the warpage went away. There was actually a TSB from Jeep about the rotors and calipers after I had fixed the problem. The problem with the calipers was the slide pins would get dirty and not release. You could clean and grease every 5-10K miles to avoid that or replace them with a different model that could cure the problem.

And yes, I got rid of the Jeep before the extended warranty expired so someone else could pay when it's self distruction continued.

wtd44

We kept our 2004 Jeep GC in the family for 4 years, got some 23K miles out of the original front rotors, changed just the front to NAPA rotors and pads, then traded it off at 60K for a new 2009 Pontiac Vibe AWD. My only "bad luck" at the end was that I had to replace the original rear pads at the last moment to make the trade. We also have a 2007 Jeep GC in the family. We bought it new, and now it has close to 15K on it. No brake problems so far. In 2005 the JGC was a new, updated model, so we hope the old brake problems are over for Jeep. After reading your post and several before it, I am now wondering if the problem might have been the composition of the original pads more than the quality of the original rotors.

wlbrown9

On the 99'-04' Jeep GC it seemed to be quality of the rotors as well as issues with the calipers not releasing. The calipers on our '00 did not release one day. I went and traded vehicles with my wife and drove that one home. The rotors got extremely hot and got a lot of shaking from them warping. Once they cooled down they were fine...these were replacement rotors from Autozone, not the original rotors. The original rotors warped without getting nearly that hot.

Jeep brake pads did suck (along with Nissan and Ford). These pads shed brake dust on your wheels so even a few miles after a cleanup, the wheels would be dirty again. My Isuzu and GMC do not have that problem.

wtd44

I suspect that there's a movement in the automotive industry toward better and better braking systems. And if so, it's about time! :sick:

ny540i6

Looking for opinions from the board....

I have had the following happen to me twice in the last few months with older vehicles, so I'm wondering whether the common denominator (me) is the problem.

One of my practices when I have to drive an unfamiliar car, especially in the wet or snow, is to get a sense of what the vehicle would do if I had to brake suddenly. I do this by getting up to about 40 mph and applying the brakes firmly - not putting it into a slide or anything, but enough to be aware of whether it pulls to one side, locks up etc. My feeling is that the knowledge might be helpful in an emergency.

In recent months I've experienced brake failures after doing this in two vehicles: a 16 year old Dodge van, sporadically maintained, with 75,000 miles on the clock, and a 13 year old Ford Explorer, also poorly maintained, with 134,000 miles on it.

When the mechanic got both on the lift the lines were corroded, rubber rotted etc, and the failure was diagnosed as "could happen at any time, parts worn out".

Both vehicles are driven by the stereotypical "little old lady." I know that the Dodge is still on the original brakes, I surely doubt that there has ever been an adventure past 60 mph in either.

So my question: Given those conditions, is it possible that my "stressing" the system could have been enough to blow things up?

paisan

Yup. Brake fluid in any car should be FLUSHED (totally replaced) every 2 years because it is hydroscopic, which means it absorbs moisture. This moisture in the lines can lead to air pockets when overheating the fluid and then brake failure. The moisture in the lines can also corrode the lines from the inside out.

-mike

ruking1

Yes and the wider implications are pretty scary. If one can look at the braking system as a "chain," the chain is only as strong as the weaker to weakest link/s.

So I guess the real first line of defense is to keep things maintained (aka CLEAN). In the process of doing that, you are actually LQQKING at the sub system/s being cleaned and have the opportunity to catch things before they become major, or in this example TRAGIC.

Off topic but demonstrates the concept; I recently discovered two worn/frayed aux belts (runs A/C compressor and starter- so nothing unsafe) on a Toyota Landcruiser with 95,000 miles, in the process of washing and inspecting the engine.

ny540i6

OK, so here's the thing (to both you and paisan) - neither of these vehicles belongs to me, no is maintained by me - and there are a ton of these rolling around out there.

I don't feel that I owe the owners any money - the evidence indicates that the systems had been falling apart for quite some time. In fact, I kinda feel that they almost owe me a thank you - trust me, it was better that I be the one driving when the brake light came on and the pedal fell!

paisan

Why were you driving them if you didn't own them? Are you a mechanic? Are they friend's cars? I think if they are friends they owe you, if they aren't I'm not sure why you would be driving their cars!

-mike

ny540i6

Part time repo man

No, in both cases these were friends that asked me to do them a favor - the Dodge's owner and her husband were on vacation, and asked me to use it to pick them up at the airport because of their ton of luggage, and the Exploder's owner needed an "extra long, extra plush" mattress dropped of on college move in day for a kid.

Mr_Shiftright

There is no way a person can damage a healthy brake system by slamming the pedal down at 40 mph. You should be able to do that every day 365 days a year. I mean, that's what taxi cabs do and we don't see them piled up in stacks on the sidewalk. (well, usually not... :P )

paisan

Agreed. I bought a used 94 Legacy about 3 years ago with 100k miles. First day I had it I took it to the track and pushed it to triple digits and braked down to 30 or less for the turns w/o issue. It was completely stock and street driven til I picked it up.

So yup if the car is in good shape hard stops should be fine no matter the age or milage.

-mike

oldfarmer50

I had a number of issues with my brakes including squeaking, squealing noise under moderate brake pressure. Had the pads and rotors replaced but I still have the noise. What should I look for next?

BTW, I have drums on the rear which were not touched. Noise sounds like it's coming from the front.

wtd44

You might try some of that brake quietening stuff. I've seen it in tubes at auto parts places. Apparently, you squeeze the product from the tube, much like squeezing a toothpaste tube. It is applied between the caliper piston and the backing pad on the disk brake pad. I don't recall the brand name! :confuse:

bpeebles

You did not specificaly say what the "failure mode" was but I am assuming by your description that the hydrolic fluid started to leak becasue a brake-line broke open under the pressure.

I assume you realize that the vehicle DOES NOT have to even be moving to check the brake system for this kind of weakness. Here in Vermont, we have an annual "Vermont Safety Inspection" which includes testing such things. A thorough inspector will sit in a STATIONARY vehicle and push the brake-pedal as hard as he can. If the vehicle does not pass this simple test (A brake line gives way), It was not safe to be on the roads in the first place.

Another "test" they do is to use a HUGE pair of pliers to squeeze every inch of the exhaust pipes. If any section of the exhaust is weak, it will crush.... again, you fail the inspection.

Bottom line - You may have been driving when the failure occored... at least you were cognizant of what you were doing.
Imagine if somone was in an "emergancy stop" situation and the brakes failed in this way? You may have saved somones life.

59er

Hi,
I had my mechanic remove my Passat ABS module for rebuild. Module Master seems to be the company most people use but BBA Reman charges less. Anyone had experience with BBA Reman or another company?
Thanks

jipster

Went to the dealership today for an oil change. They say my front brake pads are at 20-50% and recommend replacing. New front pads and rotor turning is $244 from dealership. Brakes are suppose to be simple jobs. Pads aren't that expensive. So, the cost seems a bit high. Any thoughts?

ruking1

You might want to inquire as to the hours and more importantly the rate you are being charged for labor. This will most likely be more than the materials. If you also want to do the research, how much they are charging you for the pads. So now you can shop the cheapest labor rate and/or/both supply the brake pads.

bolivar

50% left and you are thinking about replacing? Doesn't make sense.

The front pads usually wear quicker. What you might have is 50% on rear, 20% on front. You might consider replacing the front pads.

bolivar

I just read your message again. The numbers you gave pertain to the front pads.

The more important thing to be asking is why is one side at 50%, the other is at 20%.

I think there is something wrong when the pads have such uneven wear, something that should be found before just replacing pads.

jipster

The more important thing to be asking is why is one side at 50%, the other is at 20%.

I should have specified that the service advisor says I have between 20% and 50 % (20-50%) of my front pads left. Both left and right side front brakes are worn the same.

I have a Mazda MPV. At each oil change, or service, the dealership does a "full circle inspection". They check brakes, tires, battery, fluid levels etc. If whatever they check is in good condition it's given a green check mark , if it requires service soon then yellow, if requires immediate attention then red.

My last oil change 4 months ago my brakes were given a green check. Which means there was 50% or more left on the brake pads. The other day, during my oil change, the service advisor came on told me the pads were at 20%. Suggested I replace now as damage to rotors can occur if I let if go too long.

Now here's the thing. The service advisor first tells me front pads are at 20% and also wants to replace the back. Upon further questioning he says the back brakes are okay, but the front needs replacing. When I take a good look at my recommendation checklist, it says brakes checked in the yellow category means they have between 20 and 50% of pad left. I don't think pads go from 50% to 20% in 4 months, (my last oil change). So, I'm thinking my brakes are a bit worn. They fall in yellow at 20 to 50% of pad left.... probably around 40%. So, the service advisor tries the hardball approach to upselling by saying I have 20% left, instead of 20-50% left.

When I told the advisor I wanted to think about it, he offered to let me have a 10% off coupon which would save me around $24. I then said I wanted to hold off on any repairs at this time. This dealership just moved to a new location, the service department is never that busy. So, I'm thinking management is really pushing hard for the upsell. Probably going to get a second opinion as to whether the brakes need replacing. Thus far they have braked very good.... no problems.

richardson

I'd go back to that dealership and ask to see how they measure brakes. A friend of mine did that with a Lincoln dealer because they told his wife the car needed brakes. The service manager took out what looked like a stick to stir paint with that had a different color on each end. He then walked over to a car that was on the rack and shoved this stick up behind the wheel. My friend told him that you can't measure brakes that way and he said that's what we do. My friend then said what you are doing is selling people brake jobs they don't need and the answer was the same. Watch out at dealerships.

jrg38

I have a 1999 gmc savanna conversion van that 90 % of the stopping power is on the front "poor braking" all of the pads & linings are in new condition.
Could the problem be in the propotioning valve? if so can you replace with an adjustable? It does have antilock.

yooper53

opinions needed...
just priced oem rotors for my '06 honda accord. i don't mind the extra expense if it makes a difference.
what would you say? oem or aftermarket?
many thanks in advance.
dennis

bpeebles

Your question "oem or aftermarket?" is really too vague.

Obviously real HONDA brake-rotors should be quality and long-lasting.

HOWEVER: Aftermarket quality is all over the map (literally) When it comes to brake-rotors, If you ask at the parts-counter, you will be given a range of prices (and quality)

Some of the el-cheepo rotors (made in mexico) parts may rust out within 2 years. It is not worth your time to install the el-cheepo rotors unless you are planning on selling the car soon.

On the other hand, brand-name rotors such as "Bendix", "Zimmermann" or "Brembo" could be as good as OEM. ("Zimmermann" is hi-quality German steel used on Porsche!)

I realize you did not ask about pads... but this is where braking-performance will be different. (Various rotors do not alter braking-performance much at all)

DO NOT install so-called "high performace" brakepads, you may be sorry. These type of pads need to be warmed up before they start to work well. This means that a "panic stop" will NOT have full breaking power. When it comes to pads, If you want to change, it is usually better to go with a mild upgrade from stock.

Also make certain that you"season" new rotors before bedding the pads. Taking the time to do this will reward you with long-lasting brakes. (most-likely as long as you own your car)

0patience

DO NOT install so-called "high performace" brakepads, you may be sorry. These type of pads need to be warmed up before they start to work well. This means that a "panic stop" will NOT have full breaking power. When it comes to pads, If you want to change, it is usually better to go with a mild upgrade from stock.

Agree whole-heartedly.
To add...................
If your vehicle came with metallic, semi-metallic or what ever, replace with like kind.
Sometimes, replacing organic with metallic (upgrading) can result in early rotor failure. I always recommend OEM brake pads, for the simple reason that the brake pads are designed for the rotors that are on your vehicle.

dtownfb

My two cents from a lay person: If you are going to do after market brake parts, go with the brand that your mechanic uses and trust. My old mechanic loved Wagner pads and rotors. He also was able to warranty the pads for me since he used them exclusively. My current mechanic does the same thing. The amount of information on brake parts is mind boggling and difficult for someone who does not deal with it on a regular basis.

Talk to your mechanic. he can recommend a good brand.

ayc

Hi Folks- I'm new to CarSpace Forum. Appreciate your feedback. I have a ’05 Volvo, S/60 2.5T AWD. Has 45k mi. Bought it w/ 16k mi. I haven’t done any repair to the brakes yet and doubt the previous owner did. While braking I get pulsation feedback from the brake pedal and a little from the steering wheel. Much more pronounced when hard hiway braking vs.city. Replaced original tires w/ Bridgestone Potenza G019's Tires @ 35k mi. Am I looking @ rotors & pads, front & rear Replacement…or just rear? Is this usual for an S/60 with 45k mi? My driving style is average, not spirited. Estimate on what this will cost? I live in MA,

kiawah

Pulsation when braking is warped rotors. Fronts do the majority of the stopping.

bolivar

Fronts, especially when the steering wheel also pulses.