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1967 Eldorado rotor

Started by 60eldo, November 26, 2016, 04:32:38 PM

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60eldo

     can anyone tell me how the front rotors come off? I got the caliper off, now I removed cotter pin on center nut, but bolt wont budge. If I get the bolt off will the rotor slide off. By the way counter clockwise on bolt,,,right?
Jon. Klu

Glen

When you say the “bolt won’t budge” I assume you are talking about the axle nut.  That can be very tight as the factory torque is 105 ft lbs.  I believe the later cars had higher torque specs and it is possible someone over torqued the nut. 
Once you get the axle nut off the only thing that will come off is the nut.  You then need to disconnect both ball joints, and the tie rod.   Then remove the knuckle.  Now the problem is removing the rotor and hub (they are one unit) from the knuckle.  To do that you need to press the rotor out of the wheel bearing to remove it from the knuckle.  And that is as far as it can be taken apart. 
Why do you want to remove the rotor?     
Glen Houlton CLC #727 
CLCMRC benefactor #104

TJ Hopland

#2
Yours has the original optional 4 piston fixed calipers?    Or has it been converted to the later style with the single piston held on with the two long bolts?   

If its original that is what Glen described,  quite the process for a rotor that is hard to find.  If its been converted to the later style its much easier, once the caliper is off the rotor should just slide off the studs.

Not that it matters but that pressed together design that bolts to the knuckle is pretty much exactly how GM did the 88+ 3/4 ton 4x4 trucks.   The whole front end is pretty much identical.     The 1/2 ton had the bolt on hub but the rotor could just slide off.     I really have no idea why they did that pressed on thing.  It doesn't look like it would be that much stronger but it must have been.    Sure makes it a giant pain to work on the rotors.    Maybe those are why they designed those brake lathes that attach and turn them on the car?
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

60eldo

  I will post a pic soon,,,thanks
Jon. Klu

bcroe

In the past scrapping a 70-78 Toro/Eldo, I have always saved the whole front suspension to
be used by the owner of an earlier car as a brake upgrade.  Bruce Roe

cadillacmike68

It would have been SO much better if Cadillac just spent the extra 20 cents and put disc front brakes on All 1967 & up ElDorados. It couldn't have been that expensive and they went all disc in 69 anyway. I mean they had to engineer that front end from scratch for 1967 anyway.....

The result would have been plentiful parts all the way up through theb present. Same goes for 1978 RWDs

There was no excuse for the penny pinching done back then.
Regards,
"Cadillac" Mike

60eldo

 The rotors look good so I wanted to take them off maybe sell them,,,but this looks like too much work,,its crazy, I thought I would just have to take the center nut off,,anyone know the mic specs for the rotor, maybe if they are good I will try
Jon. Klu

bcroe

Quote from: cadillacmike68It would have been SO much better if Cadillac just spent the extra 20 cents and put disc front brakes on All 1967 & up ElDorados. It couldn't have been that expensive and they went all disc in 69 anyway. I mean they had to engineer that front end from scratch for 1967 anyway.....

The result would have been plentiful parts all the way up through theb present. Same goes for 1978 RWDs

Those were transition years.  The front end design was from the 66 Toronado, which with drums
had a terrible reputation of marginal brakes.  Those heavy and powerful cars needed discs more
than ever before.  The 67 disc was a bit experimental, very soon replaced with a simplified design
that was used on those FWD cars through 78.  Bruce Roe

Glen

If you are just going to sell the rotor why don’t you sell the whole thing, knuckle, hub and rotor?   
Glen Houlton CLC #727 
CLCMRC benefactor #104

60eldo

  Well so much for that. I inspected rotor today took pics and I see the rotor has separated, all finns rotten,,,thanks guys
Jon. Klu

TJ Hopland

May still be some value there to someone that really wants original disc brakes for their 67-68.     I think the CV's were also different 66-67.    Pop the ball joints and the 6 bolts in the inner CV flange and sell it as an assembly.   Or if there is time post it and see if there is any interest.    IF not you tried and can feel better about letting it go for scrap if that is where its headed. 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

bill06447

Quote from: Glen on November 27, 2016, 04:24:22 AM
When you say the “bolt won’t budge” I assume you are talking about the axle nut.  That can be very tight as the factory torque is 105 ft lbs.  I believe the later cars had higher torque specs and it is possible someone over torqued the nut. 
Wheel "lug" nut torque is 105 lb/ft. Axle nut is 150 lb/ft. The axle nut does not need to come off to remove the rotor, unless the rotor has frozen to the hub, then you may have to take the whole shebang off and press the hub off the rotor..

Bill

TJ Hopland

67 and 68 is different than 69+.   The rotor doesn't just slide off the hub studs like later cars.   It was apparently originally sold as a rotor and hub assembly and that assembly bolts to the knuckle.   To remove the assembly the axle nut does need to come off.   Its been too long since I have seen one to remember if you could actually separate the hub from the rotor,  I was thinking you could but only in a press and it took some custom spacers to get it done. 

Were the front drums the same way?   I was thinking those did slide over the studs but again its been a long time since I worked on one.    If the drums were that way it really makes you wonder why they made the disc so much different. 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Glen

Quote from: bill06447 on November 29, 2016, 07:58:33 PM
Wheel "lug" nut torque is 105 lb/ft. Axle nut is 150 lb/ft. The axle nut does not need to come off to remove the rotor, unless the rotor has frozen to the hub, then you may have to take the whole shebang off and press the hub off the rotor..

Bill

The clip below shows the torque specs for the 1967 Eldo.  It clearly shows the axle nut torque as 105.  The 1968 shop manual has the same specs. 
If you want I can go out to the garage and take a picture of the rotor/hub.  It is one piece the only way you can separate the two is with a cutting torch. 
Maybe by 1976 they made the hub separate from the rotor.
Glen Houlton CLC #727 
CLCMRC benefactor #104

TJ Hopland

Maybe the press operation I am remembering on those was to change the bearing?   I remember taking them off the car then standing watching someone do something to them then putting them back.... just way too long ago to remember details. 

69 was when they changed to what you would normally think of for a FWD car where the rotor is just a 'hat' that slides over the wheel studs.   Also was when they went to what became the typical GM single piston caliper that mounted on the 2 slide bolts. 

I think Kelsey-Hayes was the only one making disc brakes in the USA in the early days.  Everything with a disc option in the 60's pretty much looked the same.   I often wondered if there was only one caliper and it was just the wheel bolt pattern that changed between makes and models.  I wonder if in this case the whole assembly was designed and manufactured by them so that was why it was so different than the drums and later design?   Seems like at one time they made gearboxes so a bearing hub rotor combo would not have been a problem for them. 

Was the early disc hub bearing design more reliable than the later one?   Seems like on the later design the bearings were not especially reliable.    That would seem like the kind of thing the 'bean counters' at GM would have got involved in.   Gee we are buying that overbuilt disc assembly from K-H for $$$,  can't y'all go in the back and whip up something for say $ ?    What it won't last as long?   Will it make warranty?
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

bcroe

CASPRO made a heavy duty version of the bearing for use in GMC
motorhomes; has an extra bearing.  Bruce Roe

Glen

Below is a clip from the 70 shop manual.  The 69 also says the disc is separate from the hub.   I did not notice that when I stripped out my 69 and 70. 
The on the 68 the hub/disc must be pressed out of the bearing.  Then the retainer is un bolted and the bearing pressed out of the knuckle.   
   
Glen Houlton CLC #727 
CLCMRC benefactor #104

bill06447

Quote from: Glen on November 30, 2016, 12:43:15 AM
The clip below shows the torque specs for the 1967 Eldo.  It clearly shows the axle nut torque as 105.  The 1968 shop manual has the same specs. 
If you want I can go out to the garage and take a picture of the rotor/hub.  It is one piece the only way you can separate the two is with a cutting torch. 
Maybe by 1976 they made the hub separate from the rotor.
well someone's book has a misprint...

The Tassie Devil(le)

#18
I have seen misprints in Shop Manuals before, and one that nearly caused me a real problem.

The '72 Shop Manual, in the instructions for head replacement says the Torque for the Head Bolts was 155 Lbs. Ft. but in the Specifications at the end of the chapter shows 115 Lbs. Ft.

And yes, the head bolt did torque down to 155 Lbs. Ft. but I soon backed it off when I realised something was wrong.

Bruce. >:D

PS.   The '72 Shop Manual shows 150 Lbs. Ft. for the Axle Nut on the Eldorado.
'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

Glen

#19
Quote from: bill06447 on December 01, 2016, 07:36:47 PM
well someone's book has a misprint...

What manual was that clip from?  As I mentioned earlier the later cars had a higher torque spec for the axle nut.  I would not use that torque on the earlier cars.   
The 1967, 1968 and 1969 shop manuals all list the torque as 105.  The 1970 shop manual list the torque as 110.   
Glen Houlton CLC #727 
CLCMRC benefactor #104