1999 grand caravan brake rotors

have to replace by front rotors. any comments on getting the cheaper
ones from autozone/napa or paying the higher price for the
bendix/raybestos or napa to of the line ones. which are the ones you
most use. also any comments on front pads as far as the ones you like
and have the best stopping power with. thanks

 

I found the Raybestos ceramic pads glazed the rotors, causing a pulsating
stop. The people that turned the rotors indicated that they were not warped.
This happened after 5k miles.

 

Never saw a problem with them at all. But then again I've never had the
brake problems I see so many people complaining about here. Maybe I'm less
abusive but....than again my wife drives one of the vans and I can't say
that for her she's hard on stuff ;-) The biggest thing I've noted is making
sure the hub to rotor surfaces and the hub to wheel surfaces are cleaned of
rust/corrosion and to torque the wheels properly.
Larry

 

interesting. did you change the pads or live with it...what did the
people that turned the rotors say about these pads....good or bad...
thanks for your help....

 

Below is a repeat of part of a recent post of mine (in the "Advice on
1999 Jeep Cherokee vs. 2001 Jeep Cherokee" thread) that may be a general
solution for vehicles with marginal (always warping) brakes, as many of
them are these days:
For extra insurance against warping, especially on a problem vehicle,
you can have a new set of rotors cryogenically treated - will cost $75
plus shipping for treatment of a pair of rotors (based on: $1.50/pound
with min. job charge of $75 - a typical rotor would weigh in the
neighborhood of 15 to 21 pounds - rears are almost certainly not the
problem - only necessary to do the fronts). I recommend
www.300below.com. I had new rotors (fronts only) done on my '99
Concorde (LH cars are also plaqued by rotor warping) several months ago,
and the brakes are as smooth today as when I first put them on - and I
just spent a week vacation in the mountains of West Virginia with
several 3-mile 8 to 10% downhill grades braking suddenly from 55 mph to
15 mph for hairpin turns after periodic stabbing on the straightaways to
control speed - I think I just proved (to myself anyway) that there is
something to this cryo-treating. Side benefits: Rotor wear is decreased
to 1/2 to 1/3 of non-treated rotors, pad wear decreased to 80% of
normal; friction coefficient somewhere between unchanged to slight
increase.

(FWIW, I have Hawk HPS pads - very popular with the 300M and Intrepid
crowd. My cryo-treated rotors are NAPA=Dana=United Brake=Raybestos.
The rotor style is PHP - drop-in replacement for non-PHP but with better
venting/cooling.)

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

NAPA top of the line = Raybestos (reboxed as their in-house United Brake
brand) - recommended. I don't know if they make Hawk HPS pads for
Caravans, but they are popular with LH car owners.

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

Interesting as I saw an article some time ago about some testing done on
cryo treated gun barrels that were supposed to suddenly gain magic
powers also. A well designed set of experiments showed basically no
difference before and after treatment. Do you know of any real studies
on cryo treated rotors beyond your anecdote? No offense, but a sample
size of one is pretty much as insignificant as you can get statistically
speaking...


Matt

 

I certainly understand your snotty attitude - err - I mean, your
skepticism, Matt. 8^)

Seriously - yes - I realize that my experience is purely anecdotal - a
sample of one. There are some downloadable videos on the 300below.com
site on the alleged science and applications of cryotreating, including
that of gun barrels for competition.

I can't remember if they name names or not as far as competition
shooters, but they discuss that application as if it's common knowledge
in the top echelons of competition shooting that cryo-treating works and
improves scores in rapid-fire competition. Their explanation says that
the very uniform grain structure resulting from the treatment and lack
of residual internal stresses means close to zero distortion as the gun
barrel heats up during rapid-fire competition and so a tight pattern is
more closely maintained for a good shooter. If they give names and
references, then that's where your answer lies - otherwise, I agree -
it's suspect information.

They also claim that it is used to greatly increase strength and fatigue
resistance of hi-stress automotive racing parts (connecting rods,
blocks, pistons, drivetrain components, etc.), and, again, you're given
the distinct impression that it is a known real advantage in some racing
circles (quotes from a customer that they get something like 4 or 5
races out of a single engine before rebuild or self-destruction rather
than the usual one or two races. Again, I don't recall if they name
names or give verifiable references. I will say that the local speed
shop thru which I ordered their service told me that, while they did not
have racing customers who used treated rotors, they definitely have
customers who swear by it for treating engine parts.

I do remember that they link a magazine article (some trade magazine,
IIRC - hopefully not an internal "publication") about a company that is
saving a bunch of money on replacing a certain type of welding tip in a
production environment by having the tips cyro-treated - something like
ten times the life of the untreated tip - I believe they do give the
name of that customer.

To be honest, I do know of one other person on a 300M forum that had his
rotors done, and his warped - **but** he had the rotors cross-drilled
and slotted before the treatment (mine were treated right out of the
box, no other mods), and a different company did the treatment, so I
don't think it is an apples-to-apples comparison; plus his experience is
no more nor no less anecdotal than my experience.

What magazine was the article you read in?

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

I can't remember and it has been some years ago that I read this,
shortly after the cryo rage hit the shooting world. I suspect it was
either Shooting Times or American Rifleman as they are the only two that
I have received over a long period of time. I'm not able to find a
reference though.

This article may give the best reason of all ... psychology. If you
think something helps, then that helps in and of itself.

http://www.rifleshootermag.com/gunsmithing/RSgunsmith1/

Like people who claim that synthetic oil gives them a 20% increase in
gas mileage (typically based on checking one tank of gas!), or that
Splitfire spark plugs give them 10% more horsepower, etc. The mind is a
powerful device...

Matt

 

Yes, but the point is that many things can change the way a barrel
shoots or the way that rotors warp or not. Simply removing and
replacing the barrel for the cryo treatment could change the headspace,
which could change the accuracy. Also, the seating of the action and
barrel in the stock could change, etc. I'm not saying anyone is lying,
just possibly making incorrect cause and effect attributions.

For example, let's say the wheel lug nuts were grossly overtorqued and
the rotors warped. The owner takes them off, has them cryo treated and
then turned on a lathe. They are now reinstalled and this time the lug
nuts are hand torqued to the proper value. The rotors don't warp again.
It was the cryo, right? Maybe, maybe not, but I'll bet you a
steak dinner that the owner credits the cryo in any event.

I'm not saying it isn't helpful, I'm just saying I've not seen credible
evidence. The above sounds like an Amsoil advertisement. After
using Amsoil in my motorcycle and one car many years ago, I don't
believe all of their claims either.

Some things above just don't make logical sense. I can see treating the
rotors potentially making the rotors last longer, but I don't see it
making the pads last longer. Unless the short pad life was from rusted
and pitted rotors and the cryo somehow prevents rust, which I doubt.
Even if cryo serves an annealing function, which is what most claim from
what I've read, that wouldn't increase pad life.

If Amsoil as a good as it claimed back in the 70s, everyone would be
using it now. Same for cryo. I use synthetic oil and have for 25
years, but my cars don't get magically quieter, I've never seen a
measurable fuel mileage improvement (and I keep a log book and calculate
every tankful), etc. I use it for one reason only, it is less viscous
at low temperatures and my cars crank better in the winter. This is a
very noticeable effect. I believe it also gives better high-temp
protection, but that isn't a major consideration in PA.



Matt

 

Correct. They do have micrographs on their site showing 'before' and
'after' grain structure. And you are also correct in that they are not
exactly a disinterested independent third party presenting the "proof".

Agreed - you would have to know the integrity (honesty, method of
"proving", and objectivity so that, as has been pointed out, they don't
fool themselves into believing their own false hopes - that pesky
placebo effect) of the person (company) being quoted and that of the
person (company) doing the quoting.

Fair enough - I wasn't expecting it to prove anything - just some of the
stuff seems convincing combined with my own experience (not that I would
expect that to convince anyone else). I may dig a little deeper into
some of the magazine articles though with the hopes of stumbling across
something a little scientific and independent like what you point out
would be needed.

I sure am enjoying driving my car while I fool myself into thinking that
the brakes don't pulsate any more - ignorance is bliss! (I know - still
no proof - I'm just being an a**-hole) 8^)

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

Actually, this is a very old wives tale and science says no such thing.
I'm surprised someone who claims to be an engineer would propogate
this old saw...

That's good. I'll keep my eye on it. As I said before, I'm not saying
it doesn't have merit. I've just not yet personally seen convincing
evidence that it does (3rd party data, etc.) and the one reasonably
controlled experiment I read with regard to gun barrels suggested that
it did not have any measurable affect.

If it is shown to work, I'll use it!


Matt

 

I suspect that that was a true saying some years ago, and that over
time, with computer analysis and simulation, eventually science did
crack that nut (don't know for sure - just speculating). Even though it
may be a little outdated, it illustrates a valid point, and I will keep
using it. Certainly science is explaining the unkowns one by one, but
there will always be plenty of things that it can't explain but that
work in spite of man's ignorance.

No problem. I just think it's peculiar that you see people complaiing
about constant brake problems on Chysler and other forums, and so far, I
know of only two poeple (including myself) within that sizeable but
limited population that have tried cryo as a last resort. I'll bet
neither you nor I put 1% of the products we use in our home or car to
the scrutiny to which you are putting this when there is a real need for
a solution when there appears to be none due to marginal design.

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

I have a 96 Town and Country. A few months ago I went on the Tire Rack site
and found that they sell those Brembo Rotors for about what you would pay at
NAPA for their part. I combined these with ceramic pads and have no
complaints.

Richard.

 

But "science" never said this. Some scientist or engineer "may" have
said it, but even that I doubt, but science never said it.

Actually, I do for things that cost more than about $1.98. I have
a 1996 Grand Voyager and the brake rotors on it were warped when I
bought the van used with about 34K on it. I had them replaced at around
60K when the pads wore out. The van now has 136K and the rotors are
fine with no signficant warping. I can feel a very slight pulsing in
the pedal when braking very lightly, but nothing even close to
objectionable. So, for me getting my rotors cryo treated would be
fixing a problem that doesn't, for me, exist. I don't consider nearly
80K to be bad life for a brake rotor, and I fully expect these rotors to
last the remaining life of the vehicle (I expect to put 200K on it).

Personally, I believe the biggest cause by far of warped rotors is
improperly torqued lug nuts. I rotate my own tires and torque my own
lug nuts. I've never, ever had a set of rotors warp in the nearly 30
years I've owned cars and trucks. The only warped rotors I've had have
been on used cars I bought. And every one had the lug nuts on so tight
I had to use a pipe on my 1/2" breaker bar to loosen them.

I prefer to address what I consider to be the fundamental problem. But
I certainly don't object to people cryo treating their parts. If it
keeps a few more Americans employed, it is alright by me!

And in PA, the rotors typically succumb to rust long before they warp! :-(



Matt

 

300 Below charges $1.50/lb. with a minimum per 'job' of $75. My front
rotors weighted about 18 pounds each, so I was a good bit under the 50
pounds that would have maxed out the $75 minimum. It would have been
more economical per pound or per rotor to have gotten rear rotors too to
throw in with the same order - that would have put my total for the
treatment around $90 to $100, but rears are not a problem (from wear or
warpage) on most vehicles, certainly on my car (IOW the extra cost of
the new rear rotors would have been a waste of money).

The rotors themselves for my car from NAPA were $47 each.

300 below will allow you to ship them your new rotors (they
understandably will not treat used rotors because they already could
have warpage and/or microcracks), or you tell them what rotors you want
and they'll supply them and add that to the bill, which would save you
the shipping cost one way (IIRC around $12 each way from/to the east
coast).

So my total out of pocket for two new treated front rotors was $47 x 2
(rotors) + $75 = $169 (not including sales tax on the rotors). Shipping
added $24 ($12 if I had let them procure the rotors). So about twice
what the rotors alone cost.

*IF* it solves the annoying warping problem and *IF* you get
significantly longer pad and rotor wear life out of it, then it's well
worth it. These days, people replace rotors almost like it was changing
oil. 8^)

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

The "science has proved that bees can't fly" urban myth originated in a 1934
book by entomologist Antoine Magnan, who discussed a mathematical equation
by Andre Sainte-Lague, an engineer. The equation proved that the maximum
lift for an aircraft's wings could not be achieved at equivalent speeds of a
bee. I.e., an airplane the size of a bee, moving as slowly as a bee, could
not fly. Although this did not mean a bee can't fly (which after all does
not have stationary wings like the posited teency aircraft), nevertheless
the idea that Magnan's book said bees oughtn't be able to fly began to
spread.

It spread at first as a joke in European universities, at Sainte-Lague's &
Magnan's expense. But later it became a "fact" among the gullible or the
uneducated not smart enough to get the joke.

Ted

 

Bill,

Thanks. The total price seems to make this process uneconomical. As I
indicated previously, I generally have experienced warpage/pulsing around
20K miles. I usually live with this till about 25-30K miles which is about
3-4 years old. When doing the discs, I replace the rotors with Raybestos or
Napa US made and don't get any noticeable warpage till I do the brakes again
at about 60K miles. I can usually resurface these at that time and get
another 30 or more miles from them. In my case, even if this treatment
worked very well, it just wouldn't make sense financial since the rotors are
easy to replace when you have the calipers off to do the discs anyway.

Bob

 

This "test" has flaws I could drive a truck through. First, as I
mentioned earlier, unless they are treating the action and barrel as an
assembled unit, the barrel has to be unscrewed from the action and
re-installed. It is fairly well known that this operation can have a
significant affect on accuracy. Second, most barrels tend to shoot
worse when brand new, better as they "wear in" and then worse again as
they wear out. Wouldn't be unusual at all for the second 500 rounds
through a barrel to shoot better than the first 500 as the first 100 to
200 are the break-in rounds and in all likelihood dramatically skew the
group sizes of the first 500 rounds.

Since there is not just one variable here, the cryo treatment, it is
laughable to make the statement "there had been a
tremendous increase in the accuracy of the barrel brought about by the
deep freeze alone."

Which raises an interesting question: why are only the barrels treated?
I've never heard of an entire rifle being treated (barrel, action,
trigger, etc.), but it seems to me that if the benefits of stress relief
and better wear resistance are true, all of these items would benefit.
Yet I've only read about barrels being treated. Any idea why? Or have
you read about complete rifles being treated?

I'm not a metallurgist, but it sounds logical.

Sorry, but I can't place much credence in a link from the company
peddling a product or service.


Matt

 

You're welcome. Since you can figure on $30-$40 for resurfaceing a pair
of rotors and then buy another set a little later, I'm not sure I agree
that it is not economical in the long run - but that's just my opinion.
I guess I'm looking for extra margin of safety against a single event or
trip (like thru the mountains of West Virginia like I just took cutting
short the life of a regular rotor - maybe right after getting the new
pair). For me it just totally relieves pressure about using the brakes
heavily if warranted for a long downhill or whatever (whether having
just replaced them or 2 or 3 years down the road (literally). 8^)

NAPA (non-off-shore version) = Raybestos reboxed as NAPA's in-house
United Brake brand (and made in Canada - cast prominently into the
rotor). 8^)

I wouldn't call that a bad decision - it's a plan based on some logic.

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")