Chevy disc conversion question

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Chevy disc conversion question

Postby akaFrankCastle » Thu Apr 14, 2011 7:50 pm

For those of you guys running the Chevy spindles and calipers.
Did you experience what felt like excessive drag in the wheels and rotors after the install? I used all new parts in this install and now the rotors feel a bit like there is too much friction without load. The wheel will spin by hand when on jack stands, but I have about 1-2" of peddle now before things start to slow down. Took it out for about a half mile test drive and the rotors were hot to the touch. Not so much that I could feel it radiating, but hot enough I couldn't keep my finger on them longer than 2 seconds or so.

Thoughts?

Maybe I'm just freaking out because I've been running drums, and bad ones at that, for so long. shrug
Stroppe'd
1972 Sport, 302, 3 speed with old school Duff floor shifter, T shift Dana 20 with JB Fab twin stick, 4.11 gears with Trac-loc, Lincoln hydroboost, Chevy disc conversion, WH gas lift gate shock kit, 33" Duratrac tires on slots and about 2.5" of lift, Stroppe installed: bumper braces, dual shocks on all four corners, GM power steering, trans cooler mount, auto shift column, rollbar.

The Terrible One
1972 Sport uncut, 302, C4 with 1974 column , T shift Dana 20, 3.50 gears w/ limited slip, 1966 U13 Roadster kick panel, and factory power steering.

1973 Stroppe Baja project
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Re: Chevy disc conversion question

Postby crawlercreations » Thu Apr 14, 2011 8:00 pm

What did you do with your master cylinder when you converted? If you re-used your old drum MC it will need the check valve removed so the brakes don't drag. Drums require a bleed-back valve so they don't just return right away. It is what allows you to pump up the brakes when they are drums.
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Re: Chevy disc conversion question

Postby sbolt19 » Thu Apr 14, 2011 8:29 pm

Didn't you say that you were doing HB with this too? If you aren't driving it daily, slap that HB on there then come over and drive mine so you can see if there is a difference.
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Re: Chevy disc conversion question

Postby akaFrankCastle » Thu Apr 14, 2011 9:00 pm

Same master cylinder. No mods to it. Where might said check valve be located?

HB is on hold at the moment. Postponed due to life. Probably try to get it installed next week, after the BWB. Bronco parked on the side of the street and not being driven has been driving me crazy so I was trying to get it back on the road.
Stroppe'd
1972 Sport, 302, 3 speed with old school Duff floor shifter, T shift Dana 20 with JB Fab twin stick, 4.11 gears with Trac-loc, Lincoln hydroboost, Chevy disc conversion, WH gas lift gate shock kit, 33" Duratrac tires on slots and about 2.5" of lift, Stroppe installed: bumper braces, dual shocks on all four corners, GM power steering, trans cooler mount, auto shift column, rollbar.

The Terrible One
1972 Sport uncut, 302, C4 with 1974 column , T shift Dana 20, 3.50 gears w/ limited slip, 1966 U13 Roadster kick panel, and factory power steering.

1973 Stroppe Baja project
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Re: Chevy disc conversion question

Postby akaFrankCastle » Thu Apr 14, 2011 9:21 pm

Image

Look about right?
Stroppe'd
1972 Sport, 302, 3 speed with old school Duff floor shifter, T shift Dana 20 with JB Fab twin stick, 4.11 gears with Trac-loc, Lincoln hydroboost, Chevy disc conversion, WH gas lift gate shock kit, 33" Duratrac tires on slots and about 2.5" of lift, Stroppe installed: bumper braces, dual shocks on all four corners, GM power steering, trans cooler mount, auto shift column, rollbar.

The Terrible One
1972 Sport uncut, 302, C4 with 1974 column , T shift Dana 20, 3.50 gears w/ limited slip, 1966 U13 Roadster kick panel, and factory power steering.

1973 Stroppe Baja project
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Re: Chevy disc conversion question

Postby BNC04 » Fri Apr 15, 2011 4:06 am

I believe that is the one,,
Here is a thread on it from classic that explains it well.

http://classicbroncos.com/forums/showth ... r+cylinder

Some seem to need to have this done, Some don't. Sounds like you in the "does" camp.

Brett
75 D44/ARB/Disc PS. 86 5.0 Carbed- NP-435 yukon rear. 4.11 3.5 Susp lift Rampage top
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Re: Chevy disc conversion question

Postby crawlercreations » Fri Apr 15, 2011 7:56 am

Yep, my money is on the bleed back valve. Really easy to pull. Looks like it is covered in the thread link above!
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Re: Chevy disc conversion question

Postby laffycaffi » Wed Apr 20, 2011 6:34 pm

I did that conversion last Fall. Same thing happened to me. And then driving around, typically getting off the highway on off-ramps, I would get the shakes pretty hard core, and the steering wheel felt like it was going to shake right out of my hands. Pretty scary, actually.

It all just magically went away before I decided to look at it again. Still kind of scary though. I had a more knowledgeable guy look at it and he says it looks fine.
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Re: Chevy disc conversion question

Postby ZOSO » Wed Apr 20, 2011 6:54 pm

Like we were talking at the breakfast it would be the residual valve. Drums brakes require a constant line pressure of 10psi. That is to keep the springs from colapsing the wheel cylinders. On a disc set-up it is not required. The only issue you may have is the fluid requirement for the calipers. They require more volume. So to do it properly would require a new master cylinder. If it feels like you get a "lag" from your brakes then you may want to try adding a residual valve of 2psi.
Rob

74 Ranger EFI351w, 4r70w, ARB 5.13 9in, ARB 5.13D44, and a bunch of other goodies. Best of all the family memories.

04 Mustang Cobra, KenneBell 2.2 feeding a lot of boost on E85. Tire shredding machine

New project: 77 Bronco Ranger, body work and more body work.

Very little left of a 72 durango tan explorer sport
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Re: Chevy disc conversion question

Postby akaFrankCastle » Wed Apr 20, 2011 7:05 pm

Just picked up a reman 78 Bronco MC tonight. Bronco is parked until the hydroboost goes in or until breakfast this Saturday, whichever comes first.
Stroppe'd
1972 Sport, 302, 3 speed with old school Duff floor shifter, T shift Dana 20 with JB Fab twin stick, 4.11 gears with Trac-loc, Lincoln hydroboost, Chevy disc conversion, WH gas lift gate shock kit, 33" Duratrac tires on slots and about 2.5" of lift, Stroppe installed: bumper braces, dual shocks on all four corners, GM power steering, trans cooler mount, auto shift column, rollbar.

The Terrible One
1972 Sport uncut, 302, C4 with 1974 column , T shift Dana 20, 3.50 gears w/ limited slip, 1966 U13 Roadster kick panel, and factory power steering.

1973 Stroppe Baja project
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Re: Chevy disc conversion question

Postby ZOSO » Wed Apr 20, 2011 7:09 pm

If you do find that the stock 78-79 bronco brakes aren't good enough find yourself a pair of calipers off a 77t-bird. They are a direct bolt on but have a bigger piston. But then once again you'll need more volume. Thats where a f350 master cylinder comes into play. I've been through all this on my 79 already.
Rob

74 Ranger EFI351w, 4r70w, ARB 5.13 9in, ARB 5.13D44, and a bunch of other goodies. Best of all the family memories.

04 Mustang Cobra, KenneBell 2.2 feeding a lot of boost on E85. Tire shredding machine

New project: 77 Bronco Ranger, body work and more body work.

Very little left of a 72 durango tan explorer sport
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Re: Chevy disc conversion question

Postby Justin » Thu Apr 21, 2011 8:10 am

Happen to know what year F-350?
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Re: Chevy disc conversion question

Postby ZOSO » Thu Apr 21, 2011 2:53 pm

I used a 79 2wd one on my bronco. You will have to do some research and find one that will bolt up with the correct pattern. Then if you do that and keep the rear drums run f350 wheel cylinders on the drums. They should fit if you have the big bearing rear with the 11in brakes.
Rob

74 Ranger EFI351w, 4r70w, ARB 5.13 9in, ARB 5.13D44, and a bunch of other goodies. Best of all the family memories.

04 Mustang Cobra, KenneBell 2.2 feeding a lot of boost on E85. Tire shredding machine

New project: 77 Bronco Ranger, body work and more body work.

Very little left of a 72 durango tan explorer sport
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