Auto brake question (I think)

[Richard]

Here's a poser for you auto types... I'll be looking deeper into this on Saturday.

I've got a 1992/94 Chrysler New Yorker, was my mothers car.

I've had it about 2 1/2 years, about 2 years ago it needed front brakes so I replaced the rotors and pads. I didn't have the rotors machined, I simply put new parts in. As a side comment, the car has about 75,000 miles on it and another side comment, I had a Miata for 10 years and didn't put new brakes on the front of it until I hit about 100,000 miles. I do a majority of highway type driving (mostly "go" and little "stop") every day as I go to work. Point being, I'm pretty easy on brakes.

Ok, back to the Chrysler...

It has new rotors and pads in front, probably 30,000 miles of wear now?

Here's the problem:

When I'm driving the car I get a "squeek". I'd liken it to the kind of screech (subtle) that you might get when you NEED brakes and the little screech tab is beginning to scrape against the rotor.

If I slightly turn my steering wheel left/right the screech will go away. It IS wheel speed dependent, so faster I go, the faster it repeats its sound. If I slightly turn wheel left then right, there does seem to be a spot between them where the screech disappears.

Ok, so at this point I'm thinking it's the screech tab on the brakes however, this is what is confusing me... When I apply the brakes, it TOTALLY disappears and goes away. When the brakes are even gently applied, it still goes away.

I might want to add, my dashboard brake warning light blinked on the other day, suggesting to me I might be low on fluid. I checked and the fluid seemed ok.

If it helps, this car has antilock brakes.


I'm planning on taking things apart between tonight when I get home or more likely Saturday when I'll have some time to delve into it.

Just curious if anyone has any thoughts. Having the squeel go away when the brakes are applied is what is throwing me.

 

[Jimbrown]

It is because who ever installed the pads did not put any or enough anti squeel compound on the back side of the pads. Or in some cases a teflon pad. It is caused by the pads viberating when the brakes are lightly applied. It can also come from using very hard pads if that is the case it is difficult or impossible to stop.

 

[Richard]

It is because who ever installed the pads did not put any or enough anti squeel compound on the back side of the pads. Or in some cases a teflon pad.

If that is the case then I'm going to have to hire someone to go kick his hiney!! oh wait... that would be my hiney, cancel that order!

I was kind of hoping that someone would make that same conclusion as it is my base thought. (I did job myself). I don't recall exactly WHAT I did now but I don't recall any compound for the back side of pads... I'm wondering if there was a keeper of some sort back there.

Guess I'll know more when I take wheel off & see what's up.

 

[tommu56]

Richard

double check wheel bearings my daughters went and sounded the same (of course she didnt say any thing till it wiped out antilock pickup out).

tom

 

[DieselPower]

Three things to check. Anti-squeel on the back of the pads where it comes in contact with the caliper. Rotor out of round, warped. Slightly loose wheel bearing.

A fourth thing could be it is just the nature of the beast. Some pads seem to squeek more than others. If the pad's have picked up any metal or dirt and it is now imbeded in the lining it can cause a squeek.

 

[bg71361]

Richard,

I have a 92 Fifth Ave with 260,000 miles. I always do the same, replace rotors and pads when needed. I don't bother to turn the rotors when new. I agree with the above, you need to put a generous amount of Anti-Squeal on the back of the pads. Also check the low pad warning squealer tab, it may have been bent before you installed the pads.

Good Luck!
Bill

 

[Richard]

Update: I yanked the wheel off tonight & took a peek under it.

I expected rivits holding the pads on and I was therefore expecting them to squeel IF I applied the brakes.

Didn't work that way. It IS the little scraper/warning tab that is scraping against the center hub.

I guess it's going away at this point in time because of perhaps changing the angle of the pads when pressure is applied.

Bottom line, the front pads are probably down to 30% (just a guess) and basically it's front brake time.

I suppose that this being a heavier car than my Miata as well as an automatic means I won't get the milage out of these that I did with the Mazda (I did a lot of engine braking by habit)

Tomorrow... new brakes!!

 

[crbr]

Update: I yanked the wheel off tonight & took a peek under it.

I expected rivits holding the pads on and I was therefore expecting them to squeel IF I applied the brakes.

Didn't work that way. It IS the little scraper/warning tab that is scraping against the center hub.

I guess it's going away at this point in time because of perhaps changing the angle of the pads when pressure is applied.

Bottom line, the front pads are probably down to 30% (just a guess) and basically it's front brake time.

I suppose that this being a heavier car than my Miata as well as an automatic means I won't get the milage out of these that I did with the Mazda (I did a lot of engine braking by habit)

Tomorrow... new brakes!!

New rear brakes as well will assist your fronts to last much longer.

 

[LoneCowboy]

Plus, you didn't machine the rotors, so the pads couldn't break in and match the rotor, they had to try and match the old differences.
Not machining the rotors is penny wise pound foolish.
After you do that, then run the pads thru a few heat cycles to get them matching and they'll last a lot longer and work a LOT better.

 

[Richard]

Lone... I'm not sure what you're speaking of. If it's not to me then pardon my comment:

I bought brand NEW rotors when I last did it. Are you suggesting that I should have taken factory new rotors and had them machined?

If so, I simply can't belive that new rotors would need to be machined prior to use?

I was actually trying to be the opposite of penny wise & pound foolish because I bought new rotors INSTEAD of simply having the old ones machined. This way I knew I was starting fresh. If I recall, they spec'ed the rotors and they (poor memory) were within spec to machine, I simply elected to have a clean slate.

I thought I was actually being rather penny foolish and pound wise

 

[dynasim]

In my experience, there is a huge difference in the life of the brake pads. You may have had better pads on your other vehicles. Also, lubrication of the pad activation mechanism(so they release when you let up on the brakes) is very important.

I had the same problem as you, but it was only on one side. I think they got stuck engaged.

Chris

 

[LoneCowboy]

No
My bad,
i missed that, somehow I got confused. (easily done. )
New rotors should be the same as old rotors machines (albeit thicker)

 

[Jstpssng]

A johnny-come lately comment, but nobody mentioned your calipers. On an older car they may not be working up to par, and your brakes will wear out faster.

 

[OKnewguy]

My parents had a 94ish dodge shadow or plymith sundance (I do not remember which one) not a bad car really, but it had one thing they did have problems was the brakes. It stock in my memory because the brakes were toast by 40k or something. Anyway, this car had a composite piston in the brake calibers. The composite material swelled and kept the brakes on slightly all the time. When they took it in the mechanic, he new exactly what to do, he put normal pistons in and the brakes were fine from then on. That was really the only goofy thing about that car, it ran well until they sold it with 200,000 plus miles.
Good luck, Dave

 

[sandman2234]

Wouldn't it be nice if changing the pads was as easy on todays cars as it is on my 1966 Chevy?Remove wheel, remove one knotter pin, pull out the retaining pin, remove old pads, pry pistons out to allow clearance for thicker pads, drop in new pads, replace pin, install new knotter pin, replace wheel, push brake pedal to reseat pistons (forgot that one time, what a surprise when I backed out of the drive and hit the brakes and pedal went to the floor!), top off fluids. Done!!
They have the technology, why not make it simple?
David from jax