minimum rotor thickness 1970?

[eldubb440]

disc brake rotor....... I know you know......... thanks

 

[440 Charger]

It is cast on the side.

 

[MoparLeo]

There are actually 2 specs for rotors and drums. The minimum spec. And the machine to spec. The friction materials act like sand paper and wear down the surface of the rotor/drum. This is normal and predictable with factory type lining. The machine to spec is the minimum the rotors or maximum the drums should measure when the linings are changed. That way the rotors/drums will theoretically be worn to minimum specs at the same time the linings wear out.
Otherwise they are below specs while the linings are still good.
Also replace drums/rotors always in pairs.

 

[MoparLeo]

It is different for each type of vehicle. You didn't say what model of 1970. Look in your Factory Service Manual. The specs should be there.
Remember that there are 3 different rotor specs. The nominal or new thickness. The machine to spec, which is the minimum rotor thickness at pad replacement, and the discard spec, which is the measurement at which you toss the rotor.
The reason for these specs is the the brake rotor/drum converts momentum into heat and the drum/rotor must be able to absorb and dissipate this heat.
If the rotor/drum overheats, the fluid can boil, the friction material can be heat damaged both causing the vehicle to not stop as designed. This could result in a collision.
Rotors and drums should always be replaced in pairs so the braking will be equal on both side of the vehicle. This is an industry/factory recommendation .

 

[eldubb440]

It is cast on the side.

couldn't make it out........8??

they measure about .835

 

[MIKESPOLARA]

Should be .94" discard thickness

 

[Fran Blacker]

Out of 70 SM are these the right ones?.810

 

[MIKESPOLARA]

KH 4 piston calipers, is that what you have? I only see the single piston, 10.95" rotor which has a discard thickness of .94" in 1970 B bodies

 

[Fran Blacker]

Or this type floating caliper?

 

[eldubb440]

single piston, floating caliper type; 70 coronet, I assume the 1.000 -1.010 thick ones; I don't see a minimum listed there ........ they are smooth, just a bit on the thin side...... pulled from a driving car to swap in alterKtion setup a few years back....it would be nice to use them as opposed to chinesium

 

[MIKESPOLARA]

What diameter are rotors?

 

[eldubb440]

What diameter are rotors?

lol..... was unaware of so many possibilities, I'll have to check

 

[MIKESPOLARA]

If it's 11" (10.95") then .94 discard
If 11.75" then 1.18" discard

Might be cast on back but usually stamped on edge of rotor

 

[MoparGuy68]

The single piston 11” rotors on my 71 say minimum thickness 0.940”. Mine measured 0.980” and 0.972” before I had them refaced.

 

[MoparLeo]

What is important is what they measured After they were machined...Remember that unlike a drum. material is being removed from both sides at once and can get thin quickly, especially if they have hard spots or runout.
If you drive the car regularly or live in a hilly/mountainous area, you should consider replacement when they get close. Also be sure to flush the brake system, clean and repack the bearings. New seals and adjust wheel bearings to proper torque. Use the service manual for the recommended procedure for your car.

And not all rotors are made in China. Canadian, European, etc... also available.
Just shop for quality and you can find it.
Rotor Diameter: 279mm (10.98")
Rotor Height: 122.9mm (4.84")
Nominal Thickness: 25.4mm (1")
Minimum Thickness: 23.88mm (0.94" more details on - https://www.carid.com/1970-dodge-co...n-brake-rotors-2814427224.html#specifications

 

[mobileparts]

As you see, people have let you know that the discard / throw away measurements are .940 " for the
1970 - 1972 " B " and " E " body Front Hub & Rotor Assemblies.....

The internet world are strictly strictly Chineseum with warpage issues.....

I have *** N.O.S. *** U.S.A. made *** Front Hub & Rotor Assemblies as well as *** N.O.S. *** Asbestos ***
Front Disc Brake Pads for this application, such that you have the nicest, softest, smoooooothest braking system known to mankind..... and they will not rip up Rotors to smithereens....

P.M. me, as per forum rules, if you want them....
Yours, Craig....

 

[eldubb440]

holy crap, I will add to the confusion

I bought these for my 68 GTX about 15 years ago...... they measure about 11 1/8 across..... min thickness .866 ...........

are these the right ones for my 4 piston calipers?

 

[eldubb440]

and it appears they are the same as the ones that came off the 70 coronet with the single piston calipers

 

[eldubb440]

KH 4 piston calipers, is that what you have? I only see the single piston, 10.95" rotor which has a discard thickness of .94" in 1970 B bodies

my 4 piston calipers for my GTX are Bendix.... I don't see them in the above chart.... and will they work with the unused rotors I posted?

 

[eldubb440]

the rusty ones i was hoping to clean up and use on a 70 with single pistons....... they were in use, but appear to be too thin anyway.... now I'm not even sure if they are proper for the application