Manual brakes to Power brakes quesion

Technical Question and Answer - On topic to 71-74 Plymouth B-bodies only.

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mrsnicks
Satellite Sebring (RH)
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My Cars: 1971 Plymouth Satellite Sebring Plus
Location: Cameron, NC

Manual brakes to Power brakes quesion

Post by mrsnicks » Wed Dec 09, 2015 1:35 pm

Hey guys. I have a 71 Plymouth SSP with manual brakes. If I want to convert to power brakes to I just need to buy the MC/Booster combo from the big box store? Will the bracket on the firewall work between the 2 or do I need to get a Power bracket?

Thanks,

Patrick

moparmarks
Satellite Sebring Plus (RP)
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Re: Manual brakes to Power brakes quesion

Post by moparmarks » Wed Dec 09, 2015 2:44 pm

Will need the backing plate for power that goes on the firewall. Also will need the bell crank linkage that goes on the pedal.
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Southwestern Sheet Metal
71-4 B-body

mrsnicks
Satellite Sebring (RH)
Posts: 61
Joined: Mon Jan 26, 2015 10:41 am
My Cars: 1971 Plymouth Satellite Sebring Plus
Location: Cameron, NC

Re: Manual brakes to Power brakes quesion

Post by mrsnicks » Wed Dec 09, 2015 4:17 pm

It looks like I already have the plate on the engine side of the firewall.

Anyone have one of the brake pedal linkages for sale?

Found this, http://www.ebay.com/itm/331541668819?_t ... EBIDX%3AIT , but don't need both and don't want to spend that much.

Thanks,

Patrick

71bird
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Re: Manual brakes to Power brakes quesion

Post by 71bird » Wed Dec 09, 2015 6:24 pm

One other thing to keep in mind. After you get every thing installed the pedal will be closer to the floor, about even with the gas pedal.
71 Road Runner - J68

moparmarks
Satellite Sebring Plus (RP)
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Joined: Fri Mar 25, 2005 3:21 pm
Location: Grand Jct Colorado

Re: Manual brakes to Power brakes quesion

Post by moparmarks » Wed Dec 09, 2015 7:42 pm

mrsnicks wrote:It looks like I already have the plate on the engine side of the firewall.

Anyone have one of the brake pedal linkages for sale?

Found this, http://www.ebay.com/itm/331541668819?_t ... EBIDX%3AIT , but don't need both and don't want to spend that much.

Thanks,

Patrick
The manual backing plate is different than the power one.
Southwestern Sheet Metal
71-4 B-body

mrsnicks
Satellite Sebring (RH)
Posts: 61
Joined: Mon Jan 26, 2015 10:41 am
My Cars: 1971 Plymouth Satellite Sebring Plus
Location: Cameron, NC

Re: Manual brakes to Power brakes quesion

Post by mrsnicks » Thu Dec 10, 2015 5:02 pm

This is the plate on the car. Is it manual or power?
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72bluNblu
Road Runner (RM)
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My Cars: 1971 383 SSP

Re: Manual brakes to Power brakes quesion

Post by 72bluNblu » Wed Dec 16, 2015 3:35 am

Have you used power brakes on these cars before and liked them? Maybe I'm the only one, but I don't like them.

I have power disks on my Challenger and on my SSP, but I have manual disks on my Duster. I have never liked the feel of the power disks on my Challenger. They work great, but the pedal feel is awful. Same for the SSP, although I have a lot more miles in the Challenger (over 50k now). The manual disks on the Duster require a little bit more leg effort (not a lot), but the pedal feel is much better. The pedal feel on the Duster is crisp and responsive, while the pedal feel on the Challenger and SSP is somewhat more vague. Again the brakes work great, they just don't feel great.

I only mention it because if I do any conversions, it will be to convert my power brake cars to manual brakes, not the other way around. The Challenger will definitely be converted to manual disks. The SSP will probably stay power, but just because its a numbers matching car.
'71 SSP GA4
'71 DartGT EL5 (#65 in the GT registry)
'71 DartGT GK6 ( #69 in the GT registry)
'74 Duster/71 demon tribute- primary driver
'72 Challenger-secondary driver

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moparite
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Re: Manual brakes to Power brakes quesion

Post by moparite » Wed Dec 16, 2015 8:44 pm

I guess you never tried to stop in a hurry when going 100+ with manual drums. It's not easy even with both feet on the pedal! Don't ask how i know this. LOL My Challenger (along with all my other mopars) has power disk's and loved them! No way i would convert to manual.

mrsnicks
Satellite Sebring (RH)
Posts: 61
Joined: Mon Jan 26, 2015 10:41 am
My Cars: 1971 Plymouth Satellite Sebring Plus
Location: Cameron, NC

Re: Manual brakes to Power brakes quesion

Post by mrsnicks » Thu Dec 17, 2015 2:25 pm

Back on track.. Is the booster plate on there now for a manual or a power brake setup? Do I need to purchase a new plate?

Does anyone have the linkage for sale?


Thanks,

Patrick

72bluNblu
Road Runner (RM)
Posts: 39
Joined: Mon Jul 15, 2013 7:28 pm
My Cars: 1971 383 SSP

Re: Manual brakes to Power brakes quesion

Post by 72bluNblu » Sat Dec 19, 2015 5:03 pm

mrsnicks wrote:Back on track.. Is the booster plate on there now for a manual or a power brake setup? Do I need to purchase a new plate?

Does anyone have the linkage for sale?


Thanks,

Patrick
That plate is neither. As in, that's not a stock plate. Your car has been modified, the bolt heads are a dead giveaway. You should either have studs that come through from the pedal mount on the other side of the firewall, or studs on the power booster. You should not have bolts in either case. On top of that, the stock plates have a rounded bend on the edge, it's not just a straight bend like on your plate. Sorry, while I have linkage on my Challenger that eventually I won't be using after I convert to manual disks, it's still on the car at the moment and I'm not ready to do the swap yet.

This is what a stock plate should look like...

Power brake plate
Image

Manual brake plate
Image
moparite wrote:I guess you never tried to stop in a hurry when going 100+ with manual drums. It's not easy even with both feet on the pedal! Don't ask how i know this. LOL My Challenger (along with all my other mopars) has power disk's and loved them! No way i would convert to manual.
Guess you're wrong, because I have in fact tried to stop in a hurry with manual drums from 100+. Which is why I never mentioned DRUM brakes in my post. My cars have manual DISKS, which I thought I made pretty clear. Adding a power booster doesn't improve your stopping distance, assuming you're strong enough to actually apply the brakes properly. If everything is sized properly, ie, master cylinder bore, wheel cylinder bores, and piston diameters (for disks), you shouldn't need two feet regardless.

Like I said, I have had, and have, both power and manual disks on my cars. The power disks are noticeably worse for braking feel (not stopping distance, that's the same). Yes, the effort is less, but the braking feel is much less precise. Fine I suppose if you're driving miss daisy, not acceptable if you're running autoX or road courses, or simply prefer a more performance based car.
'71 SSP GA4
'71 DartGT EL5 (#65 in the GT registry)
'71 DartGT GK6 ( #69 in the GT registry)
'74 Duster/71 demon tribute- primary driver
'72 Challenger-secondary driver

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moparmarks
Satellite Sebring Plus (RP)
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Joined: Fri Mar 25, 2005 3:21 pm
Location: Grand Jct Colorado

Re: Manual brakes to Power brakes quesion

Post by moparmarks » Thu Dec 24, 2015 8:01 am

Classic has the plate and linkage for 100.00. Buy them when they have 25% off for 75.00
Southwestern Sheet Metal
71-4 B-body

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