Braking probs on 70 Chall

[miss_mopar]

I am having ongoing problems with my
70 Challenger When I stop the brakes
are grabbing, pulling and most of all
vibrating very badly. I have disc in
front and new rotors were put in
about a year ago. Since June I have
had the rotors turned 4 times...why
do they keep warping?? Mechanics
cant figure it out..they just keep
turning the rotors. Been to 4
different shops. They say everything
else looks fine. I put new Cragar S/S
on around the same time this all
started to happen. Dont know if that
has anything to do with it or not.
They vibrate braking at any speed. If
anyone has experienced something like
this with their mopar or anyone has
any ideas..please reply..thanks.

Wanted to add: This is a conversion
from drums, done about 4 years ago.
The calipers were used when i did the
conversion but one has been replaced
new about a year ago.

Also, that is why I mentioned the
Cragars...because since they were
installed is when I started having
these probs. They did use an air tool
and my mechanic said they tightened
too much and that is why the rotors
warped. Needless to say I got my
money back from that other shop. But
I had the rotors turned and the
Cragars put back on, but like Pro said
it doesnt last long and they start
messing up again and have to return to
shop to get them turned again.

So do i need new rotors? Rotors and
calipers? These rotors were only a
year old...and yes, they cost me a
fortune. I still believe the install
of the Cragars is what did it..fought
with the shop for weeks. Well, better
go now...getting mad again. Any other
info...please respond. Thanks again.

[This message has been edited by miss_mopar (edited December 29, 1999).]

[Thunderstruck]

Swap in some other tires and rims to check it out. If the calipers are loose in thier mounts, or binding that could cause the issues you mention. Loose wheel bearings too. Just because a "mechanic" checked it out don't mean squat. I'd venture to say your E body is older than most of the mechanics.

Steve

[PRO]

Several things come to mind,1st though rotors will warp when too much heat is generated,if this is a 10 sec 1/4 mi car and thats how you drive it that would be normal,I imagine its not and your not,Excessive heat can also come from sticking calipers,they are the lowest point in the fluid system and all the garbage in the fluid tends to reside there.when you apply the brake the caliper piston travels outward and makes the pad contact the rotor,when you let off the pedal the piston should retract,it may not if its got alot of debris in the piston bore,it also may not if the caliper slides are rusty and lacking lubrication.This is like driving around with your brakes on and that will generate some serious heat.In any event it sounds like you should have the calipers rebuilt and be sure to lube the slide with Slyp-glide(napa).Flushing the brake fluid every 2 years will prevent this in the future.Also over torquing the wheels could cause the rotors to warp but not ususally on this design,make sure theyre using a torque wrench(set to 60ft lbs)not an air wrench.Once a rotor is warped you cannot get it trued by remachining,it will feel better for a short time but then it returns,the reason being that once the metal gets too hot it loses its temper(no it doesnt get mad)that is its ability to withstand heat.If your brakes are pulling to one side(espcially b4 they were warped)thats a sure sign that you have a frozen caliper.Hope that helps......PRO...

[Elwenil]

In addition to what PRO has said (which is right on) I can also say that when you get your calipers rebuilt, make sure they replace the caliper pins and rubber bushings. I had the same problem on my 72 Charger and even after fixing the calipers I still had problems, and with the price of these rotors, I couldn't afford to do this every month. After doing a bit of nosing around I found that there are little spring clips that go on the caliper bolts that I was missing. These help hold tension against the caliper to help pull it back from the rotor. I tried to rob these off of junkyard cars, but they all crumbled as soon as they went on my car.I bought a caliper parts kit from the local parts store that was made by Raybestos that had everything I needed and solved the problem no sweat. No more caliper rubbing and rotor warping. Not to mention the increase in top speed from not having the extra drag. Would you believe my calipers were holding me at 125 and now she goes 140?
~Elwenil~ ~.\|/.~

the rotrors are too thin and will keep warping

[68Brent]

Don't know if this info is of any use, it happened a LONG time ago, but I had the same problem with a 73 Charger. The rotors kept warping and getting hard spots, I turned them 3 or 4 times, but the problem kept returning, even though the rotor thickness was still above the minimum. I eventually replace the rotors with aftermarket ones, and never had the problem again. That was in 1975, and as I recall it wasn't an unusual problem. I always assumed Dodge got a bad batch of rotors.

[johnjdodge]

Somewhere in the 70's mopar redesigned rotors front the earlier two piece assembly to the newer one piece casting. It was found that the two pc assembly was warping on the c bodies, and the single casting was changed to all bodies in times. Unless one is using NOS rotors, I don't believe what's out there today is anything but the single casting.
Check those rear brakes!! If they aren't up to snuff, then the fronts are being asked to do extra duty, a sure sign of warppage & excessive wear.
THose spring clips under the head of the caliper bolts were "anti-chatter" clips. They weren't intended to "push" the caliper away from rotor.

[Elwenil]

As far as "anti-chatter" clips go, I beg to differ. They are listed in the 1972 Chrysler Parts Catalog as Part Code 5-05-46 POSITIONER, Disc Brakes. Part number 3461770-1. I also quote from the 72 Dodge Service Manual, page 5-44: "Four machined abutments on the adaptor, position and align the caliper, fore and aft. Two positioners installed over the guide pins, control the movement of the caliper along with the piston seal, and assists in maintaining proper shoe clearance and are also required to hold the inner bushing in place." The anti-rattle spring was a long wire-like object that went over the back side of the caliper and hooked on the ends of the caliper pin. Part number 3461894.

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~Elwenil~ ~.\|/.~

[This message has been edited by Elwenil (edited December 30, 1999).]

[miss_mopar]

Just wanted to thank all of you for your help and ideas on my brakes. It ended up being the calipers sticking and half the shops I had taken it too couldn't even figure it out. So I have new rotors and calipers (rotors were beyond turning since they had been turned way too many times already) and all is well now. Thanks!

P.S. It pays to take your car to a reputable shop...all I can say.

[bruce]

Miss Mopar, nice to find out that people of the opposite sex are interested in Mopar Chat.com This site has resolved a lot of problems for me cause I am talking to the entire Mopar clan. Bruce

[ehostler]

miss-mopar, I know this is off subject, but are you the same miss mopar that lived in Rancho Cordova in '89, with a '70 Challenger ragtop?

Ed

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'96 Dodge Ram 1500 SLT CC 360 4X4
'68 Charger 383-4

[miss_mopar]

Originally posted by ehostler:
miss-mopar, I know this is off subject, but are you the same miss mopar that lived in Rancho Cordova in '89, with a '70 Challenger ragtop?

Ed

Hi Ed...well I do work in Rancho Cordova..and have since 1989...but I dont have a ragtop (I wish)...you mean there was another Miss Mopar back then? lol

[ehostler]

I didn't know her, just wanted her car. The plates were either mzmopar or msmopar.

She lived near Mather AFB, just off of Bradshaw(cati-corner to Albertsons).

Ed

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'96 Dodge Ram 1500 SLT CC 360 4X4
'68 Charger 383-4