Stop here! Let's talk about brakes

gdo123 · February 2002

What you described is exactly what I used to do.
Now that my car has ABS, I thought it wouldn't be a good
idea to force the brake fluid back into the ABS components.
If this really isn't an issue for ABS, then I'll continue to change
the pads without bleeding, and save the bleeding for a
separate job. Thanks,

fleetwoodsimca · February 2002

gdo123: I have relied on repair manuals for such matters, and I have no recollection at all of any of my ABS systems ever requiring special procedures when moving the pistons back. You just about have to move them, so that the thickness of the new pads can be accommodated. Rear caliper brakes are another story in many cases, and require twisting with a device made for such. Changing the fluid should be something you could defer until later, depending on the condition of the fluid at the pad change time. That seems very reasonable to me.

mjart · February 2002

Hi! I test drove a 1998 Mustang Cobra, and everything seemed ok, EXCEPT that I noticed (with the window rolled down) repeating squeal that seemed to be coming from the brakes - the squeal or chirp increased frequency as I sped up, decreased frequency when I slowed down, and was especially noticeable when driving by a large close object (like another car or building). I want the car, but of course refuse to purchase until the problem is solved. One of their mechanics said there is nothing wrong... that the brake pads are new and sometimes brand new pads will result in this squeal for a little while. This just doesn't seem right to me. Do any of you have any ideas as to what could be causing this squeal? I appreciate any thoughts.

bburton1 · February 2002

Agree with most of the post but I open the relief valve on the back of the caliper assembly and force all the brake fluid out that opening and then just as I get the brake piston to the bottom, close it up so that no air enters. The fluid in your caliper has been really fried and it is not a bad idea to push it out of the system and not back into the system. Watch where the fluid goes-it is hell on paint.

fleetwoodsimca · February 2002

I suspect you will find that the (near) racing quality of the pads in the Mustang Cobra are made of material that really is a great performer in vehicles that get the brakes pushed to the limits in sporting or racing conditions. My understanding is that most such materials are noisy! It seems to be a trade off.

gsleve · February 2002

If in the procedure that was outlined previously on changing pads one can siphon brake fluid out of the master cylinder and fill it appropriately and then proceed to open the bleeder screw attach a clear hose redirect into a basin or canister of some sort depress piston expel fluid lock bleeder and refill master cylinder to appropriate level.

I don't think one would have to bleed the brakes after this procedure, however the rear brakes could use some bleeding to expel remaining fluid within the line.

tboner1965 · February 2002

but brake fluid is hygroscopic. (It absorbs water.) What does that mean? When you are changing the pads, you should flush the fluid. As brake fluid absorbs water, the boiling point drops. You really don't want your brake fluid turning to steam as you apply the brakes in a panic stop.

Water gets in through microscopic pores in your rubber brake lines.

So my vote is for cracking the bleeder valve on the caliper when you push that piston in. Replace the pads, then flush the remainder of the old fluid out in a thorough bleeding of the lines.

FWIW,

TB

fleetwoodsimca · February 2002

It is very much possible to change pads and/or shoes without ever touching the bleeder valve on the caliper or wheel cylinder. Now, if you install new calipers and/or wheel cylinders, you must do a bleeding procedure. Regardless of motivation for fluid exchange, the Mityvac tools provide another approach possibility. The brake fluid bleeding units are designed so that you can do a pressure exchange of fluid. You literally pump fluid from your attachment to the bleeder valve clear up to the master cylinder reservoir. An assistant is very handy at this juncture to watch the level at the reservoir, while removing fluid from there as needed.

alcan · February 2002

It was mentioned here, although I originally wrote the article in response to a question about glycol vs silicone fluids:
http://www.batauto.com/articles/brkfld.html
Take a look at what happens to the boiling point of gylcol brake fluids with only 3% water absorption.

george92 · February 2002

Hi I own a 980lds intrigue 20000ml abs. When ever I drive over a bump/bumps and simultanously step down on the brakes I can hear a springing noise coming from under the front end. It only happens when I hit the brakes and the bumps at the same time I complained to the service 2 years ago. They said they couldnt find anything wrong. otherwise the car rides ok. Can any one give me some insight. thanks

fleetwoodsimca · February 2002

That sounds like you are activating the antilock feature of the front brakes, thus getting the "spring" sound.

george92 · February 2002

Thanks for your reply. I kinda thought that be the answer.But is that normal. Is it common for
all abs to make a springing noise?

fleetwoodsimca · February 2002

Would buzzing also describe your sound? I had a 1993 Explorer that did that a lot, due to momentary front wheel braking on bumps. I always figured that the wheel was "over braking" while it was rebounding upward and the traction on the tread was low enough for the system to detect the front wheels were turning at different rates. For that vintage Explorer, that was normal. No harm ever came of it.

sivi1 · February 2002

if new brakes are so good why don't i get 25k mi on pads on 3 s-class m-b's that i have owned. i guess they are soft pads since the rotors don't warp. maxima i also own has 40k mi pads are good, but rotors are warped ? trade off?

gdo123 · February 2002

I have 32,000 miles on my Chevy Monte Carlo. The shop just told me I have
about 3,000 miles left on the pads. I started pricing out the pads, and it
looks like the ceramic pads are standard OEM and run about $90 for front
and $60 for back pads. Carquest offers lifetime replacement on their
ceramic pads front $108 and rear $83. Anybody have opinions on brake
pads?

brucer2 · February 2002

Assuming similar driving conditions, how long a pad lasts depends on several things. One is how thick the friction material is (duh). The other thing is pad composition. At one end of the specturm are soft pads with a high coeficent of friction. These are good for performance, but wear faster and produce more brake dust. At the other end are the "lifetime" pads. They are "hard", don't dust much and tend to wear the rotors faster than the pads (the lifetime warranty is on the pads not the rotors). There is also the operating temp factor: do the brakes work well cold and fade at high temps, or the other way round.
I think that unless someone is willing to put up with fast wearing pads and lots of brake dust for better performance, The best all around performance is with OEM pads, rotors, and shims, etc.

svier1 · February 2002

I bought my wife a 1994 Lexus ES 300 recently and need some advice about the brakes. The car only has 34,000 miles on it and according to all shop records the rear pads were repleced recently but that the front pads are still original. The brake system was just flushed by the Lexus dealer (in another town)less than 4,000 miles ago.

The problem is that the pedal feels VERY soft and seems to have a lot of "play" in it. My wife claims that the reaction time for the breaks seems slow at best. No leaks or low fluid levels detected.

Any suggestions???? Does it seem that it needs new pads or could there be air in the lines?????

fleetwoodsimca · February 2002

Take a look at this:

http://www.raybestos.com/

brucer2 · February 2002

If the brakes began to feel soft right after they were flushed, then they let air into the lines and they need to be bleed. If bleeding doesn't help, then there might be a problem with the master cylinder (but I doubt it).

opera_house_wk · February 2002

This was an unusual problem I had. If I would be going slow, 20 mph or less, and I gently applied the brake, one of my rear wheels would lock. Often this would happen when I was being courteous to let another driver out of a parking space. Startled by the rubber squealing, the other driver would give me annoying looks or the finger. Never had a problem at highway speeds or when braking hard.

When I got around to pulling the rear drums, I found that the stainless steel cable for the brake adjuster had broken and the end connector was jammed at the edge of the brake shoe. Funny thing was that it never made any grinding or rubbing sounds. This is the only time I have ever replaced one of these cables.

mandarino · February 2002

How do you tighten the emergency brake cable on this grand voyager? looked everywhere. Bled the back brakes. took off the drums and adjusted the pads. I think they're self adjusting anyway. Don't see anywhere to adjust the cable. I followed it from the foot pedal (EB) to the rear drums. Am I missing something?

fleetwoodsimca · February 2002

Find the two ends of the external cable (sheath) and look for a screw adjuster and lock nut-- or reasonable alternatives for these. If there is such, do the adjustment there. Effectively lengthening the sheath gives the effect of shortening the cable inside it. Another way some cables are effectively shortened is by forcing a spacer between the end-of-cable keeper and the active arm that the keeper rests inside of. This effectively shortens the cable. The best approach is to go to a manual for that vehicle. Public libraries often have them (e.g., Mitchell Manual). "Cable clamps" were used years ago, but seldom on today's vehicles is there a place to attach one. Unfortunately, many newer vehicles really require a cable replacement in lieu of an adjustment.

protegextwo · February 2002

I own a 2000 Mazda Protege with 35,000 miles. I asked my Mazda Service Advisor how often do I need to change the fluid? He said, "never". He said, "that is one of the fluids we top off during normal maintenance". He said, that "replenishment is enough"?
I have been told every 2 years is about right, by some fairly savvy friends.

Questions:
1.) How much should this cost?
2.) Where should I have this done?
3.) Would it be more cost effective to have the fluid changed, when the brake pads need replacement?

BTW, the owners manual only suggests checking the brake fluid every 7,500.

Respectfully,
Larry

shipo · February 2002

Brake fluid, left to its own devices, will absorb water (bad), which can boil when the fluid gets hot from stop and go driving or mountain driving, said boiling will cause a bubble in the line and limit the braking performance of the wheel that said line is attached to (very bad).

You might want to take a page from many higher performance car manuals, use the best quality brake fluid AND do a complete system flush/fluid replacement every two years. It might just save your life.

Best Regards,
Shipo

fleetwoodsimca · February 2002

On my own vehicles, I just wouldn't consider a routine type brake fluid change in less than say, 75K miles. I would CONSIDER a fluid change at the same time as a brake pad/shoe replacement, depending on my opinion of the fluid's condition. When I have a commercial outfit do my brake jobs, they will likely insist on changing the fluid as part of their desire to lower their liability for work performed. I would go along with that. Always remember that "ought to" is a much better position than "should have."(:oÞ

alcan · February 2002

Inexpensive and simple to use test strips are available to determine the water content of brake fluid. Any glycol fluid over 3 years old will have minimum 4-5% water.

fleetwoodsimca · February 2002

Where do you get the strips, and what do you ask for? Talk about a motivater to get you to change the fluid, this must be it!(:oÞ

brucer2 · February 2002

Good info on ABS brake system maintenance here:

It's time to start expecting ABS problems

http://www.autotruck.net/library/brakes/breaks6.asp

alcan · February 2002

I've quoted from the link brucer2 posted:

The trouble is they're not opening the bleeder when they push the piston back, so all the sediment in the caliper is getting forced up into the ABS unit. Think about what happens to a guy who does brake jobs, but has no scan tool. The car came in with the warning light out, and now he's got a light he can't turn off. To fix this, you go back with a scan tool and cause the system to go into the self-utilization cycle and pump itself clean." A hotline authority with a quality brake parts outfit corroborates the importance of this, saying, "Never, ever push in a caliper piston without opening the bleeder."

and:
In the past, some brake authorities said that flushing and refilling the system with fresh fluid wasn't worth the effort because you can't get all the old stuff out unless you disassemble the calipers and cylinders. True, you won't be able to eliminate every drop of the contaminated liquid, but you can get most of it, and that will effectively reduce the amount of moisture in the circuits. Besides water, there's that nasty sediment, which is a combination of rust and the ashy residue of burned glycol.

anf for fleetwoodsimca:
Those neat new test strips you dip in the fluid are another alternative, and they cost less than a dollar a shot.

Thanks brucer2 for posting a link to corroborate what I've been advising all along.

mandarino · February 2002

Has anyone actually tightened up an emergency brake cable on a voyager(or caravan, I suspect the procedure would be the same)?. Is the only alternative a new cable? Please refer to #123, I tried everything suggested. Unless I'm missing the obvious, I don't see anything to tighten up the slack on the cable from under the vehicle, inside by the EM pedal or by the rear drums.

mjbwrtr · February 2002

i changed the pads on the front of my saturn today. the left rotor was smooth and clean but the right had two tiny grooves worn in it. i simply put the brakes together and put the tires back on. those tiny grooves arent going to compromise my stopping power, right? it stops fine now and i have no "warpage" symptoms. should i do anything extra, like replace the grooved rotor with a new rotor? and if i do so, should i just replace the other one "while i am doing it"?
we want to run this car 200k if we can...its got 56k on it now, so i am sure i will be doing brakes again in a couple years.

alcan · February 2002

If the grooves are less than .060" and there's no pull or pulsation, you're home free.

fleetwoodsimca · February 2002

Alcan is the expert here, and I hope he will agree that anything you do on one side should be done on the other, such as replacing brake disks, wheel cylinders, etc. There are a few things suited to "single-sided" changes, such as minor hardware replacements. My point is that observing symmetry from port to starboard will help to prevent pulling or other symptoms of uneven braking.

alcan · February 2002

Well, not so much an expert as having paid my share of dues in skinned knuckles over the years. LOL It still amazes me how many people want just a single leaking wheel cylinder or seized caliper replaced. Pointing out that the other one's the same age and in about the same condition usually gets an accusation of overselling.

rayfbaird · February 2002

I do it at the 30,000 mile checkup, or in the case were brakes were replaced, 30k from that time. We drive in mountains regularly. Won't take any chances. Plus if done regularly bleeding is a much easier process for the mechanic.

coria63 · February 2002

What steps do I need to take to change brake
pads on abs system

alcan · February 2002

No different than without ABS. Just take care not to damage the wheel speed sensor wiring while working around the caliper supports.

fleetwoodsimca · February 2002

Have you got opinions on the various current grades of Raybestos pads? What brand and grade do you recommend for all around service?

alcan · February 2002

Quiet Stop are great for pedal feel, no squeal, and low dusting. I haven't had any negative feedback from anyone whose car I've installed them on. Super Stop are a better choice for more spirited driving with less fade and faster recovery, but expect more noise and dusting. I've also had comments about brake grind on initial application after the car's sat overnight cause by slight surface corrosion on the rotors from iron dust from the pads. A couple of pedal applications cleans it off and they're good to go. I've tried Brute Stop on my own car but found they needed to be heated up before performing well, noisy, rough pedal feel, and chewed the **** out of the rotors. The upside is they'll stop you faster than anything except a tree.

stonewall8 · February 2002

I just put new rotors on my truck. The old rotors were so bad that they were glazed, pitted, and corroded after 151k mi. and were never turned. They had cracked apart the pads, which were 50% worn in thickness. One backing plate was warped from heat. I put the lowest price brake pads on and brakes now are smooth and quiet. I was told that more expensive metallic pads wear out disk rotors. Is this true? Can cheaper pads ruin rotors?

alcan · February 2002

Low end pads won't usually cause rotor damage, but they may have a shorter service life, be more prone to squeal, fade faster under heavy use, and take longer to recover.

fleetwoodsimca · February 2002

I suspect Quiet Stop would meet my needs best. Thanks for the advice. Now! If I can just remember that name when the time comes... (:oÞ

alcan · February 2002

Just think Shhhhhhh..... LOL

fleetwoodsimca · February 2002

That'll work! (:oÞ

chamre · February 2002

It is most certainly ABS activation. The force from the road on the wheel becomes very heavy than very light as you go over a bump. When the force becomes light, the brake force quickly decelerates the wheel. The ABS system kicks in to prevent wheel lock-up. (The system can't tell if the impending lock-up is caused by a slick road surface, or by the fact that the force on the wheel is very small).

The springy sound you are hearing is most likely the Delphi version of ABS. (I'm not sure, but I believe Delphi supplies the ABS for the Intrigue). Most ABS mfgs. use soleniod valves to regulate pressure. The remove pressure from a wheel by opening one valve, and replenish the wheel pressure when needed by open a valve to the master cylinder pressure. Delphi, on the other hand, uses a system that adjusted the volume between the ABS unit and the brake to control pressure. Think of it as a mini-master cylder moving forward to increase pressure and backward to reduce pressure. The springing sound you hear is the mechanics moving the piston. Most other ABS systems have more of a buzzing (motor running) and clicking (solenoid valves opening/closing) sound.

rhetor · March 2002

I have the typical Jeep Gr. Ch. brake disaster -- rotors warping within 5K miles, multiple resurfacing and new pads. Now I'm out of warranty and it's time to make a real fix. To that end, I have some questions:

1. I'm hearing Raybestos QuietStop pads are the way to go. Do I need these front and rear, or front only (I'm only at 22K mi.), or is this something to check with a mechanic?

2. The rotors are a piece of junk, are warped, and must be replaced. Are Raybestos rotors good? Better or worse than Power Slot rotors? Stillen rotors are more expensive; are they worth it?

3. Do I just buy the parts and go to my usual mechanic, or get him to order them? Or would you recommend finding someone who mostly handles high-performance parts?

fleetwoodsimca · March 2002

I suggest you ask the mechanic concerning your choice of brands. If you ask him if he can get such-and-such brand for you, 99.999% chance he says yes. There is extra profit in the deal when the shop gets the goodies. If you bring parts in without them explicitly wanting you to, you are committing a faux pas that makes for bad relations.

yantai · March 2002

We've just got a new 4DR CIVIC EX. One thing we are curious is the brake and steering. We have to press the brake harder than normal (compare with accord lx - maybe twice strength needed). Dealer techician said it is normal, because it has ABS. The steering is also a little bit heavy. Anyone has knowledge to share? Thanks.(BTW, I have almost no knowledge about cars, ABS, etc.)

jjstokes0430 · March 2002

I need some help. I am woring on a car that someone put someting in the master cylinder besides brake fluid. It looks like it might be power steering fluid but no way to be sure. What can I do?

heng · March 2002

You can flush the system by bleeding fluid from each wheel. You will go through several cans of brake fluid but that approach is the only way to get the wrong fluid out.

This will be a messy and time consuming job and probably require a helper to work the brake pedal while you work the bleed valve at each wheel.

Stop here! Let's talk about brakes

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