Manual disc brakes vs power discs?

[timinator]

I'm converting my manual drum brake 69 Charger to discs. I have the option of keeping the manual brakes with discs or upgrading to power disc brakes. Anybody have an opinion on how powerful manual disc brakes are compared to power discs? My cam will easily provide enough vacuum for power brakes so that's not an issue. If power brakes aren't that much more powerful, I'd prefer to stay with manual ones.

[moparguy01]

I prefer the manual disc brakes over the power brakes. I think it has better pedal feel.

[is_it_EVER_done?]

My suggestion is to convert the brakes over first while maintaining the manual brake MC and drive it around a bit to see how you like it. With the stock 1 inch MC, manual disk brakes feel better than power and work just as well (my opinion). The problem comes when you use a bigger bore MC such as a stock power brake disk MC, or one of the aluminum ones, without a booster, as the bigger bore MC's will cause high pedal effort, decreased braking modulation and poor or even dangerous stopping ability in a heavy car.

A big bore MC can be used with easy pedal effort and good modulation by re-drilling the brake pedal to increase it's mechanical advantage, but the stock manual drum MC is all I use anymore. There cheap and available at any parts house.

The only thing you need to do if you use the stock MC is check the fluid level every couple of months, as the drum MC doesn't have the fluid capacity of a disk MC, so you need to keep the fluid level topped off.

[Charger-Bodie]

I prefer the manual disc brakes over the power brakes. I think it has better pedal feel.

[Just 6T9 CHGR]

Ill let you know in a few months

I have the manual disc SSBC kit on the car right now and while the car stops 100% better, like stated above the pedal effort has increased a bit.


I just completed getting all the "correct" parts to swap in a Bendix power booster.  Will be putting it in when it warms up a bit here.

I, however, wouldnt recommend using a manual drum brake master on a disc brake car....

[is_it_EVER_done?]

I, however, wouldnt recommend using a manual drum brake master on a disc brake car....

WHY?   --- As you stated  ....  "I have the manual disc SSBC kit on the car right now and while the car stops 100% better, like stated above the pedal effort has increased a bit". ...

I'm guessing that you haven't used the 1 inch manual drum MC since you don't really seem to be totally happy with the stopping ability of your car. What is the diameter of the MC your using?

The only thing I can say in defense of my original suggestion is that I have done dozens of disk upgrades, over more than 30 years, for my self and many others, and the formula I posted has PROVEN (well over a Million miles of use) to be the best/cheapest way to go with virtualy NO problems. I stand by my suggestion as TOTALLY safe!

[chargerbr549]

I converted my 69 R/T Charger to the big factory discs and I kept the factory drum brake master cylinder, it has an awesome pedal feel and stops great, the only two reasons that I understand they suggest you not using the drum brake cylinder is because of fluid capacity which has already been addressed and the residual pressure check valve that the drum cylinder has, I removed that and I check my fluid level once in a while and I haven't had any problems for the last 6 years.

[Chatt69chgr]

There is a disc brake master that was supplied for non-booster cars.  I took one out of a Duster.  I do believe it has a 1" bore.  And it has the large and small reservoirs like disc brake cars have as well as the longer brake rod.  I would think that you could get this unit rebuilt from Cardone.  The rod can be obtained from Mopar Performance as an adjustable rod.  A rubber bushing goes in the aluminum master piston to retain the brake rod.  I can't say if the non-booster configuration was used in B-bodys or not but as Is it Ever Done says has stated, manual disc brakes work very well.   

[bull]

My Charger had manual brakes with drums all around from the factory but I put disc brakes on the front using this as a guide: http://www.moparaction.com/Tech/archive/disc-main.html

[71charger_fan]

http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=3158816&an=0&page=2#Post3158816

[Just 6T9 CHGR]

I, however, wouldnt recommend using a manual drum brake master on a disc brake car....

WHY?   --- As you stated  ....  "I have the manual disc SSBC kit on the car right now and while the car stops 100% better, like stated above the pedal effort has increased a bit". ...

I'm guessing that you haven't used the 1 inch manual drum MC since you don't really seem to be totally happy with the stopping ability of your car. What is the diameter of the MC your using?

The only thing I can say in defense of my original suggestion is that I have done dozens of disk upgrades, over more than 30 years, for my self and many others, and the formula I posted has PROVEN (well over a Million miles of use) to be the best/cheapest way to go with virtualy NO problems. I stand by my suggestion as TOTALLY safe!

Your opinion, I have mine.  I am not an engineer, nor do I claim to be an expert.   I do however trust in reading from some companies that manufacture braking systems that say NOT to use a master cylinder that was not DESIGNED for disc brakes.
Some say Holley, some say Edelbrock....to me a carb can be modified & tried....a braking system should not.

Again, my opinion.

[RECHRGD]

This thread interests me.  I bought the same SSB manual front disc conversion as Chris and, yes, it does stop much better with no pulling at all.  However, the pedal pressure required to haul the car down to a stop in a panic situation is unacceptable to me.  I won't even let my wife drive it anymore. OK, that's a good thing .  Bob

[is_it_EVER_done?]

This thread interests me. I bought the same SSB manual front disc conversion as Chris and, yes, it does stop much better with no pulling at all. However, the pedal pressure required to haul the car down to a stop in a panic situation is unacceptable to me. I won't even let my wife drive it anymore. OK, that's a good thing . Bob

This is why I'm passionate about the brake upgrade subject. For these aftermarket suppliers to be offering "supposed" brake upgrades, that are either a poor mismatch and/or potentially dangerous, is a travesty in my opinion!

I can't tell you how many times I have been to Swap meets/shows and tried to explain to these dealers/manufacturers/suppliers that the big bore MC's, mismatched disc bore diameters to rear wheel cylinders, and generic - non adjustable - proportioning valves are dangerous in a manual setup. Amazingly, not one of them will agree, nor do they care! I can also state that not one of them seems to know anything about hydraulics or hydrodynamics. The only saving grace is that 99% of these cars are not driven in regular traffic nowdays and only see very limited usage.

I'm guessing that close to half the old Mopars out there have, AT MINIMUM, minimally effective brakes, and AT WORSE, dangerous brakes. unfortunately, just because someone has a booth/magazine add/web site/or has a magazine column, people tend to believe them.

I'll keep rallying against the mistakes, incorrect assumptions, and false advertising, but it's a losing battle as the internet is amazing in it's ability to make incorrect information become "absolute fact".

Just so you know, bigger brakes, other manufactureres brakes, or different brake pad/shoe linings would not solve your problem. Only a booster, re-engineered pivot point for the MC push rod, or smaller diameter MC will do that.

[RECHRGD]

So, your recommendation would be to use the original MC rather than the one supplied with the kit?  As I recall the new one wasn't much larger than the drum brake unit.  I'll check tomorrow and maybe post a picture of it.  I was thinking of getting one of those boosters that runs off of the power steering pump like NYCmile runs, but haven't gotten around to it yet.  Sounds like maybe I don't need to go to that expense.   Bob

[resq302]

This thread interests me. I bought the same SSB manual front disc conversion as Chris and, yes, it does stop much better with no pulling at all. However, the pedal pressure required to haul the car down to a stop in a panic situation is unacceptable to me. I won't even let my wife drive it anymore. OK, that's a good thing . Bob

This is why I'm passionate about the brake upgrade subject. For these aftermarket suppliers to be offering "supposed" brake upgrades, that are either a poor mismatch and/or potentially dangerous, is a travesty in my opinion!

I can't tell you how many times I have been to Swap meets/shows and tried to explain to these dealers/manufacturers/suppliers that the big bore MC's, mismatched disc bore diameters to rear wheel cylinders, and generic - non adjustable - proportioning valves are dangerous in a manual setup. Amazingly, not one of them will agree, nor do they care! I can also state that not one of them seems to know anything about hydraulics or hydrodynamics. The only saving grace is that 99% of these cars are not driven in regular traffic nowdays and only see very limited usage.

I'm guessing that close to half the old Mopars out there have, AT MINIMUM, minimally effective brakes, and AT WORSE, dangerous brakes. unfortunately, just because someone has a booth/magazine add/web site/or has a magazine column, people tend to believe them.

I'll keep rallying against the mistakes, incorrect assumptions, and false advertising, but it's a losing battle as the internet is amazing in it's ability to make incorrect information become "absolute fact".

Just so you know, bigger brakes, other manufactureres brakes, or different brake pad/shoe linings would not solve your problem. Only a booster, re-engineered pivot point for the MC push rod, or smaller diameter MC will do that.

And this is why I am glad I have a factory brake set up in my car.  To make it even better, it is a factory disc brake set up.

[poppa]

Hey all,I too am currently sourcing parts to "upgrade" to disc brakes.This is for a 69 Charger.I remember ,in my younger days,being able to go to the parts store and buying a caliper rebuild kit.I can not find one for the 4 piston caliper.I have found a local parts store that will sell me rebuilt calipers (not a bad price $99) but am concerned with the fact that in a pic on their web page,it shows them and I can not make out the "tapped" bolt heads that hold the two halves together."Tapped" meaning where the bracket for the hose is mounted.None of my parts have really been checked out yet,except one caliper half.It looks like some one took this one apart eons ago and left them outside.The outer half(non mounting)had it's pistons removed and the bore is pitted.I've heard you can get these resleeved.Everthing else I'm told is available,seals,bearings,etc.Rotors though,are not and one of mine looks kind of thin on one side.Should I continue in this direction(with some advise from this fine group)or should I chuck it all and go a different route.Any thoughts or help would be greatly appreciated.The grandson thinks poppa's car is really cool and with valuable cargo as that,I want the stuff to work when I need it.Thanks to all at DC.com....

[Chatt69chgr]

Unless you are trying to do a concours restoration, you might want to forget using the OEM 4-piston calipers.  Everything about them is expensive.  In 1970, Chrysler changed to the single piston caliper for the Charger.  Much better.  Start with the Disc-O-Tech article in Mopar Muscle Magazine.  I think that was the correct magazine.  But it's easy to find.  Just type in mopar disc brake upgrade in google and it will go directly to it.  Read that and search on threads on this site and you will find a ton of information.  It will take a while to absorb all of that but after you have looked this stuff over, you will have more questions.  Mainly, you will have to decide if you want to buy a kit or try to do the upgrade with existing Mopar parts, some of which can be sourced in the junkyard.  If you want to do it the cheapest way possible but really good, use F-body spindles off a 76 to 80 Mopar, stay with the smaller rotors, and don't use a power booster.  There are literally zillions of those spindles out there in junkyards cheap.  Get the caliper adapters that come with them which I think are sliders at the same time as well as the dust shields.  The slider calipers are available rebuilt from Cardone for around $15 each.  Need ones for 79 Cordoba.  Correct brake hose for both sides is BH36828 Bendix.   Keep the brake rod going to your manual master and buy a new disc master.  Do some research but you want a 1 inch bore and absolutely no bigger. I think Raybestos and Cardone both have the right one.  Keep your exisiting brake line plumbing but put in a adjustable line pressure unit from Mopar Performance.  Need to plumb it in the brake line going to the rear.  Probably put on frame rail under car under drivers seat.  Rotors are available from Oreilly in Wagner made in USA.  Bearings available from Autozone in Timken.  Use Bendix pads on front.  Important to use MKD84FM pads.  These are expensive but don't skimp on these.  If rear wheel cylinders have never been changed, put new ones in to get expander cups.  Thats it unless somebody else can think of something I missed.  The F-body spindles are about 3/4 inch taller than the ones you have but most don't think this matters.  May have to modify the front end alignment some.  I don't recall what the change is.  But I don't think you will be able to make the change and do a excellent job to boot any cheaper than this.

[poppa]

Chat69,no it's not a concours by any means.When I started though I thought it would be simpiler to use the factory stuff thinking everything would pretty much just be rebuilding and bolt up.I do ,by the way have power brakes and a sway bar.I heard some of the aftermarket stuff is a problem with the sway bar.Thanks for your reply....

[bull]

Here's my parts list:

2 Spindles: 1974 Dart (used) $90
2 Caliper adapters: 1977 Fury pin style (used) $36 incl. shipping
2 Rotors: 1977 Fury (new) $91.21
2 Calipers: 1973 Challenger (rebuilt) Loaded with new semi-metallic pads, pin fastener set, etc. $129.98
1 Disc Brake Master cylinder: 1973-1980s Dodge truck (rebuilt) $28.76
2 Hoses: 1980 St. Regis (new) $30.98
2 Oil seals: 1977 Fury (new) $3.49
2 Outer wheel bearings: 1977 Fury (new) $8.50
2 Inner wheel bearings: 1977 Fury (new) $11.18
1 Wilwood Adjustable Proportioning Valve: $42.50
1 Wilwood Residual Pressure Valve: $16.46
Misc.: $15

Total: $504.06

The jury is still out on the MC I bought, I don't think it's going to work. The only thing you might have to buy used if you go with the Mopar Action kit (http://www.moparaction.com/Tech/archive/disc-main.html) are the caliper adapters, dust shields and spindles, although those can be purchased new now too through various vendors. If you happen to find an old set of calipers have them rebuilt or use them for their core value if the cost is offset, otherwise just buy them outright and try finding a set that are already loaded with the semi-metallic pads.

Also, regarding the drum brake MC mentioned by is it EVER Done?, I have to say it sounds a bit precarious too if you're constantly having to worry about checking and rechecking the fluid level. I don't want to start a debate over which MC is better or safer because I haven't looked into it as much as I'd like to yet but on the surface it seems the drum brake MC has some shortcomings too.

[poppa]

Just some fyi ,I just came across a place called ecihotrodbrakes.com that has a kit for $575.00 using factory drum spindles. I know absolutly nothing about them or the quality of the productI still can't believe no one makes a rebuild kit for these (Bendix 4 piston) calipers.That's kind of like not making tires or spark plugs or an exhaust for these cars.I want to use the current rims and tires (Keystone Classics,14 inch).Oh well,for now the search continues,as we get closer to April I will probably change my mind.Good luck guys...

[bull]

Just some fyi ,I just came across a place called ecihotrodbrakes.com that has a kit for $575.00 using factory drum spindles. I know absolutly nothing about them or the quality of the productI still can't believe no one makes a rebuild kit for these (Bendix 4 piston) calipers.That's kind of like not making tires or spark plugs or an exhaust for these cars.I want to use the current rims and tires (Keystone Classics,14 inch).Oh well,for now the search continues,as we get closer to April I will probably change my mind.Good luck guys...

It is and it isn't. That Bendix 4-piston deal wasn't much good to begin with and I think that's a big part of the reason no one bothers rebuilding them. If there was an outcry for such a service things would be different but there really isn't. It's probably like trying to find someone to build aftermarket Inland shifter parts, reproduce original Carter 2bbl carbs or stamp out some 14" hub caps, it's just not a big priority to the customer as a whole. I've had to find a lot of goofy stuff no one wants but I've managed to find everything I was looking for so far with little help from the masses. If you really want the original calipers rebuilt you'll just have to keep looking. Where there's a will (or lots of money) there's a way.

[Chatt69chgr]

By the way rechrgd, the reason I said to use slider caliper adapters and slider calipers and the particular bendix pads is because first, the small sliders are laying around all over the place----the large ones that you would use with 11.75 inch rotors and not easy to find and unless you are doing road racing the small rotors will do just fine.  And second, the reason for the particular pads is that is it ever done explained to me that the reason he doesn't use pin calipers anymore is that nobody makes a good pad for them.  Just thought I would throw this info in too.  And lots of folks think that the slider is a stronger caliper although there is some debate on this.  I think that you may find the small pin caliper adapter kind of hard to find too.