#1  
Old 05-08-2023, 09:31 PM
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4dblnkldude 4dblnkldude is offline
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Default ‘79 brakes the same as a ‘70

I recently picked up a 70 firebird Esprit and it needs some brakes. Five months ago I acquired a 79 Formula. I bought brakes for the 79. Are the rotors, calipers, hoses, pads, drums, shoes, and wheel cylinders the same? It looks to me that the rear is the same. They are both 10 bolt drum brake rears. The 70 has manual front discs and cant seem to find info on the fronts. I cant find dimensions of the rotors but everything looks the same. What gives? Am I missing something? Is this easier than I think?

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Old 05-08-2023, 10:58 PM
'ol Pinion head 'ol Pinion head is offline
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Early 2nd Gen spindles take early rotors. Wheel bearing size changed before '79
Calipers changed slightly with casting numbers changing over the years,
Hollander interchange calls for early calipers on early spindles.

If you were to swap the entire knuckle assembly's (loaded spindles) off the '79, the swap would be possible.

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Old 05-09-2023, 12:45 AM
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1979 to 81 hoses have Metric banjo ends (10mm) vs. earlier 7/16", so the calipers will have different fittings also.

79-81 rotors use bigger outer bearings. And different tie rods too IIRC.

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Old 05-09-2023, 11:32 AM
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Thank you!

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Old 05-09-2023, 11:38 AM
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So I'm correct regarding the rear drum stuff?

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Old 05-09-2023, 01:24 PM
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i do believe the rear stuff is all the same.
for a while I ran aluminum drums off a 1980's Monte Carlo on my Firebird...

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1970 Formula 400
Carousel Red paint on Black standard interior
A no-engine, no-transmission, no-wheel option car.
Quite likely one of few '70 Muncie three speed Formula 400's left.


1991 Grand Am: 14.4 @ 93.7mph (DA corrected) (retired DD, stock appearing)
2009 Cobalt SS: 13.9 @ 103mph (current DD; makes something north of 300hp & 350ft/lbs)
  #7  
Old 05-09-2023, 04:03 PM
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Wasn't there a switch to finned drums in 74? I think all 2nd gen are compatible, but I remember my 74 having finned drums, but my 72 did not.
Yeah those Aluminum drums from the 80s g bodies were the hot ticket. I had some before converting to disc brakes in the rear. "felt" faster with those on there.

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Old 05-09-2023, 04:27 PM
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i think it was maybe 1975, but yes.

I actually intentionally found OE style unfinned drums a while back.

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1970 Formula 400
Carousel Red paint on Black standard interior
A no-engine, no-transmission, no-wheel option car.
Quite likely one of few '70 Muncie three speed Formula 400's left.


1991 Grand Am: 14.4 @ 93.7mph (DA corrected) (retired DD, stock appearing)
2009 Cobalt SS: 13.9 @ 103mph (current DD; makes something north of 300hp & 350ft/lbs)
  #9  
Old 05-09-2023, 10:41 PM
'ol Pinion head 'ol Pinion head is offline
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'74's had smoothie style drums, also last model year for:
-spotwelded flange style backing plates
-long style 2nd Gen emergency brake cables
-1310 u-joint pinion yoke
-rear axle line junction on off the top of the rear cover

One of the spoils of pulling & dragging in an obscene amt of 8.5 rear cores, stacks of nice thick rear drums

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Old 05-10-2023, 10:37 PM
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Vast knowledge,,, unreal. Thank you gentleman!

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