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1969 CADILLAC LIMO FRONT BRAKE ROTORS / DISCS

Started by 1969cadillac, January 31, 2014, 04:27:34 PM

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1969cadillac

HELLO!

does anyone out there have any experience with drilled and slotted discs fitted to 69 model RWD cars ??

CQUENCE MOTORSPAORTS has these for sale @ $173.00 each :


http://www.ebay.com/itm/150988043469?item=150988043469&viewitem=&sspagename=ADME:X:RTQ:MOTORS:1123&vxp=mtr


my question is - do they really offer better stooping power ? ( this is a 2.6 tonne limo ? )

and are they noisy - someone suggested that they would be ?

also !!!

I can buy standard rotors in :

Raybestos  5800R

or WAGNER BD60241

is one brand better than the other ??

there is a bit of a difference in price  - but I cant remember at the moment which one is cheaper ??

Murray Mules

The Tassie Devil(le)

G'day Murray,

Not sure what the main differences between the Limo and DeVille front rotors are, but when I had to replace the front rotors on a '69 DeVille I upgraded to 1972 DeVille rotors.

These are a one-piece hub and rotor, and were a lot cheaper than the separate parts.

There was a slight alteration to the dust cover, and it used a different inner seal, but once done, it was possible to get replacement parts easier, as there is a greater supply of '70's parts than for the '69.

Over on the Modified Cadillac website there is a description on what to do, but for some reason, I cannot find it, even though I wrote it myself.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe

cadillacmike68

I've never seen any mention in the shop manuals WRT Series 75 brake rotors being different. That idea on using 1972 rotors is a good idea. I was going to get a spare set of rotors, I might get those instead.
Regards,
"Cadillac" Mike

Gene Beaird

With all other dimensions being the same drilled and/or slotted rotors will actually provide less performance than solid rotors.  It's a simple matter of both mass (for heat absorption) and surface area (for the pads to transfer heat to).  They can help prevent gas buildup under the pad with extended use, which can help performance and reduce noise some, but I find that brake noise is mostly an issue with the choice of brake pad material. 

We have slotted rotors on our 96 Impala SS, and they squeal whenever the brakes get warm.  I believe the PO put whatever pads were cheap when he installed the rotors, though, and I haven't been annoyed enough to change them. 

Personally, I'd use drilled and/or slotted rotors ONLY if they were either all that was available (which is a problem these days with older cars), or we're using larger diameter rotors in a racing setup (where you're usually replacing the rotors after each race anyway).  Rotors that are not slotted or drilled will have more mass and surface area, important things trying to emergency stop a heavy car from highway speeds.  Slots and drill holes can provide stress concentrators that can lead to cracking of the rotor, which you really don't want.

If the disc brakes squeal, you can try to chamfer the eedges of the brake pad where it contacts the rotor and/or cut a shallow slot radially across the pad surface with a hack saw.  I used to do this with the old compound metallic brakes when they'd start squealing.  Otherwise, you're probably better off changing to a better pad or trying different compounds.

Gene Beaird,
1968 Calais
1979 Seville
Pearland, Texas
CLC Member No. 29873

JVA

What Gene said. Drilled and/or slotted rotors help reduce brake fade, but do provide less absolute stopping power and are more prone to cracking (well, drilled ones are - not slotted ones). Unless you plan on tracking your car, solid is where you want to go. Hmmm... I will revise that statement. Slotted rotors are also useful for helping to keep brake pads clean. Aggressive driving with an otherwise under-braked vehicle can result in glazing on the pad surface. Slotted rotors can help reduce or eliminate that effect. I could see how a slotted rotor might be beneficial on a heavy car with an old brake (ie almost universally undersized for modern traffic) system. I would still stay away from cross-drilled. That's an almost indefensible technology for the street. :)

cadillacmike68

#5
Quote from: The Tassie Devil(le) on January 31, 2014, 05:37:25 PM
G'day Murray,

Not sure what the main differences between the Limo and DeVille front rotors are, but when I had to replace the front rotors on a '69 DeVille I upgraded to 1972 DeVille rotors.

These are a one-piece hub and rotor, and were a lot cheaper than the separate parts.

There was a slight alteration to the dust cover, and it used a different inner seal, but once done, it was possible to get replacement parts easier, as there is a greater supply of '70's parts than for the '69.

Over on the Modified Cadillac website there is a description on what to do, but for some reason, I cannot find it, even though I wrote it myself.

Bruce. >:D

Bruce,

Just those two items, grinding down the dust cover (the inner part where it meets the rotor) and the inner dust shield? That's it? they take the same bearings?

I know they take the same pads. These full size RWDs took the same pads from 1968 all the way up to the last Fleetwood in 1996.


I'm asking because 1968-71 rotors seem to have vanished from the parts inventory.

Bruce, is this the link you are looking for?

http://www.modifiedcadillac.org/articles/onepiecediscswap/onepiecediscswap.html
Regards,
"Cadillac" Mike

The Tassie Devil(le)

'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe