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Old June 18th, 2019, 02:37 PM
Chuck78 Chuck78 is offline
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Default Re: Dana 44 rear disc conversion 5 lug, drum type parking e-brake vs Eldorado/Seville combo calipers?

Well now... on the rear discs, it turns out that the ,79-85 Cadillac/Buick Riviera/Olds Tornonado & 79-81 WS6 Trans Am rear disc/e-brake calipers are getting a bit scarce, and the core charges are pretty spendy...
The only manufacturer that has both left rear & right rear both stocked is Centric. Fortunately all rebuild parts seem to be available, but if you need just a caliper piston, you're looking at $60 each, and they are side-specific due to the emergency brake corkscrew/worm gear mechanism.
Also, I learned something new that the Trans Am calipers have different part numbers than if you look up a Cadillac Seville. This I did not know. slightly different rebuild kit part numbers as well. BUT the cross reference also shows a Cadillac Eldorado 1979-1985 on the Trans Am part numbers, AND the Eldorado shows up on the Seville caliper cross references as well, but no Trans Am.... The T/A listing also says 79-81 Trans Am AND 78-81 Camaro, but I NEVER knew this to be an option on the Camaro, and I was a huge 70-81 Camaro fanatic in my teenage years through my 20's... The Trans Am calipers are not available as a set anymore, they seem to be quite scarce. I had better grab what is left for my dad's 1980 Trans Am and my old 71 RS/SS 396 that I sold him (upgraded to '79 WS6 T/A 3.23 positraction with rear discs, Tremec 5 speed, and a built 406cid)... for future repairs...



Here are the brakes, the Caddy/Riviera/Toronado listings. The brake lines are also metric, M10x1.5 thread, so you'll need an adapter coupler/bushing/reducer fitting on one end or the other going to the axle line from the hard line on the frame.


*CENTRIC 14162512 Reman.; Includes: Hardware, Rear Left $97.79 ($50 core)
*CENTRIC 14162511 Reman.; Includes: Hardware, Rear Right $102.79 ($50 core)

Centric semi-loaded calipers are remanufactured to meet exacting standards ensuring worry free performance for the life of the caliper. Each Centric caliper is 100% pressure tested and inspected to guarantee proper operation and fitment. Centric semi-loaded calipers include hardware and brackets where applicable.
CENTRIC Warranty Information:
90 days/3,000 miles
BUICK RIVIERA 1979-1985
CADILLAC ELDORADO 1979-1985
CADILLAC SEVILLE 1980-1985
OLDSMOBILE TORONADO 1979-1985












Caliper Rebuild Kits:
*RAYBESTOS WK1415 {#301415} SEAL KIT; Professional Grade; Disc Brake Caliper Info
Rear $10.54 each caliper, not side-specific



Caliper Pistons:
*RAYBESTOS DPS85068 Professional Grade; Steel Phenolic Steel Info
Rear Left $60.79

*RAYBESTOS DPS85067 Professional Grade; Steel Phenolic Steel Info
Rear Right $60.79


(you can see the worm gear or whatever it is technically called, on the internal side of the piston, center hole)



Also, it looks as if a 79-82 Corvette master cylinder may work well for this application at a 1.125" bore:
*RAYBESTOS MC39052 {#2539052} Element3 $37.79


I originally went with a 67 1-ton truck master, and planned to remove the residual valve on the front circuit when I converted to front disc. this master left the rear drums with far too much power over the fronts, and a proportioning valve was necessary, as it should be on any conversion really. I did power booster conversion as well at same time, so my brakes became much more powerful and I could lock up the rear drums first, which would lead to dangerous handling and caused me to slide sideways through a highway exit sign when some moron went from start & stop traffic at 0-15mph and floored it across the solid white lines triangular area right before the grass at the exit, at which I was barreling down the exit lane at 45mph on wet road conditions...


It looks like on my order for all new front end polyurethane a-arm bushings, premium ball joints & tie rods, etc for my 1973-1987/1991(88-91 Suburban is same as 73-87 pickup/suburban) front end swap, I ordered a more commonly available and thus more affordable front disc/rear drum 1980 CHEVROLET C10 SUBURBAN 5.7L 350cid V8 ACDELCO 18M66 Master Cylinder, for $ 34.79. This was also a 1.125" bore master cylinder same as the Corvette 4 wheel disc master, and will work for rear discs whenever I do the swap, simply by pulling the internals out and removing the residual valve that is on the rear circuit.
On the single circuit 60-66 brake master cylinder that I use as a clutch master cylinder, the residual valve is at the end of the spring at the very front where the sole outlet is. I'm not sure how a dual circuit dual drum master works as far as residual valve location, or a disc front/drum rear, but if I recall (foggy memory from decades ago), the front reservoir/piston-plunger is for the rear brakes? so perhaps it would have the same setup? I have seen some that have residual valves on the outlets where the brake lines attach as well, but I don't believe these are like that.




****Soooo.... due to the impending scarcity of these 1979-1985 rear calipers with integral parking brake, the newer disc with integral drum parking brake in the rotor hat doesn't seem like that bad of an idea other than bolt patterns on the axle and the axle housing possibly needing altered, and the rotor hole or axle register needing turned down
__________________
Chuck in Ohio
*'62 GMC 1000 Panel Truck - 305D/Saginaw 4sp soon: 351C V6 + AX15 5sp OD trans, & 73-87/91 disc brake front end, rear Cadillac calipers/ AWD Astro rotors, Dana 44 redrilled to 5 lug
*'88 Suzuki Samurai 4x4 project, VW 1.9L mTDI turbodiesel, Toyota V6 LandCruiser drivetrain, full floater axles, future LWB bed stretch
*'77-'79 Suzuki GS motorcycles, '76 Rickman CR900 roadracer.
*Dirtbikes: 2 Kawasaki KDX220R's, '77 Suzuki PE250, '83 PE175

Last edited by Chuck78; June 18th, 2019 at 03:18 PM.
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