Drumb to Disc Swap

[DmoparBerg]

Hey all, looking to swap my the drumb brakes to disc on my 73 Challenger here this winter. Anyone have any suggestions on kits? I've seen a few from Wilwood, Classic Performance, etc. Wondering what people have had experience with and who had the best experience with which kit?

Thanks All!

 

[ted s]

i used factory parts from a 73 dissc brake car

 

[moparleo]

The 73 came with disc brakes on the front. Only Darts were available with front drum in 73. Are you talking about a rear conversion ?
Rear conversions are a waste of money you can use elsewhere. The front brakes do 70-80 % of the braking.
The rear drum brakes if kept adjusted properly are more than up to the job unless you are in a road course type competition.

 

[70chall440]

Dr Diff in your guy, he is a Mopar dude and can offer a variety of kits based on what you have and want.

 

[DmoparBerg]

The 73 came with disc brakes on the front. Only Darts were available with front drum in 73. Are you talking about a rear conversion ?

moparleo, yeah looking for kits for the rear. The front brakes aren't the best as well looks to be original equipment so wondering for others that have 73's if they have swapped those out as well?

 

[Challenger RTA]

Search here and Read PROPORTIONING VALVE -- 4-WHEEL DISC BRAKES Read disc brake conversion Read Wilwood Disc on a 73 Challenger Read 4 Piston Caliper Disc Brake Conversion Kit For 14" Wheels and read some more.​

 

[MoparCarGuy]

Read this article on using factory parts to improve your brakes without the headaches of going aftermarket. Next, watch every E-body video you can here.
A killer factory setup is to go with a Bendix E-body power brake booster, a 3461187 master cylinder, factory 11.75" front rotors (most call these 12") and either stock 10" or 11" rear drums. The TA-style metering valve is a must have item and is approximately $71. If you have enough engine vacuum, you are good-to-go. If not, use the LEED Brakes VP002 ELECTRIC VACUUM PUMP KIT - BANDIT SERIES and you will have a system that can hang with any aftermarket kit out there.

 

[moparleo]

Again, skip the rear disc, you don't need them.
How hard are you braking that you don't like the factory fronts?
You don't have ABS so it will only stop as good as you can modulate the pedal.
You can go to a larger rotor with the setup that you already have, just need a larger caliper bracket and go with more aggressive pads for quicker stops.
But the more aggressive the pads are, the quicker the rotors wear out as well.
Rear disc brakes are more of a "glamor "item.
The factory front disc and rear drum is more than adequate for any normal street driving situation.
Your money though...

 

[fasjac]

I used Wilwood on my 73 cuda. With the original booster in place, they work great. Left the rear drum brakes in place with overhaul. I haven’t gone to disc in the rear because it’s works very well as is.
I still have the factory set up stored but, 12 years ago I thought the aftermarket drilled and slotted rotors looked cool. Doing it over, I’d left the factory in place as they worked great. Just sharing this.

 

[DmoparBerg]

Read this article on using factory parts to improve your brakes without the headaches of going aftermarket. Next, watch every E-body video you can here.
A killer factory setup is to go with a Bendix E-body power brake booster, a 3461187 master cylinder, factory 11-7/8" front rotors (most call these 12") and either stock 10" or 11" rear drums. The TA-style metering valve is a must have item and is approximately $71. If you have enough engine vacuum, you are good-to-go. If not, use the LEED Brakes VP002 ELECTRIC VACUUM PUMP KIT - BANDIT SERIES and you will have a system that can hang with any aftermarket kit out there.

This is great thank you!

 

[Challenger RTA]

I my self have two and 1/2 sets of hens teeth. from a Chrysler imperial rear disc brake. I had them since the mid 70's,and have yet to put them on. Came to the conclusion not worth it. 1 from what I recall,had to use a roller bearing not a tapered bearing. 2 Braking 60-70% of braking is from the front brakes. 3 My conclusion as why the Imperial had 4 wheel disc breaks,is that it was a the weight. disc disperse the heat better then drum. and it had ABS.After decades of driving,in the land of ice and snow and where the hard winds blow.One develops a habit of pumping brakes for a controlled stop.Now one can not buy a car with out some type of ABS.I don't care for them.But in a complete panic stop it's worth it. but on the other side more to break.The best modification that should be done would be rear ABS. As far as rear drums as long as maintained self adjuster working,keep adjusted by using parking brake.The rear drums are more than adequate ! the people that designed all those systems were not brain dead engineers. They had the best tools of the time,pencil paper slide rule and a exercised brain. 1950 Chrysler Crown Imperial: Four Wheel Disc Brakes Standard – But Not Like Modern Discs May be the only way I would put rear disc on.is the rear brakes were missing or beyond repair or if it was rear ABS. This my own personal understanding and opinion.

 

[DmoparBerg]

Again, skip the rear disc, you don't need them.
How hard are you braking that you don't like the factory fronts?
You don't have ABS so it will only stop as good as you can modulate the pedal.
You can go to a larger rotor with the setup that you already have, just need a larger caliper bracket and go with more aggressive pads for quicker stops.
But the more aggressive the pads are, the quicker the rotors wear out as well.
Rear disc brakes are more of a "glamor "item.
The factory front disc and rear drum is more than adequate for any normal street driving situation.
Your money though...

My main concern is safety. Not braking hard really at all it just takes a LOT to get the car stopped currently. I just bought it in Sept so haven't had it out on the roads much but when I have I've had to make sure there is plenty of room between stops as yeah she ain't stopping on a dime. Pretty much have to have the brake pedal to the floor with decent pressure to get her to stop. Hoping to take the kids in the car at some point but trying to do a lot of the safety items here over the winter. I haven't disassembled the front brakes yet but could be certainly related to some issue there. The brake lines look fairly new, the master cylinder might be original though, can't speak to the rest of the brake components as yeah need to do an inspection on those.

For the most part the car is original and I don't think the guy I bought it from really did any maintenance on it the 4 years he owned it. He was more just interested in showing it off at shows so didn't really fix much of anything.

 

[Challenger RTA]

LOT to get the car stopped? No matter what you put on the the back the front does most of the work. Master cylinder not working? proportioning valve not working? Back wheel cylinders not working?Front brakes working?Or just need bleed?The Engineers already done the the work.do the maintenance.Or upgrade to a larger front rotor.

 

[DmoparBerg]

LOT to get the car stopped? No matter what you put on the the back the front does most of the work. Master cylinder not working? proportioning valve not working? Back wheel cylinders not working?Front brakes working?Or just need bleed?The Engineers already done the the work.do the maintenance.Or upgrade to a larger front rotor.

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Yeah pretty much have to have the brake pedal to the floor during any stop also get some pull to one side so yeah. Bottomline is yeah I need to do a deeper inspection on the whole system. I started the thread though as yeah advice on the conversion kits as still thinking of swapping the rear, I yes realize it's more of a looks thing than functionality. Thanks all for the advice.

 

[Challenger RTA]

Yeah pretty much have to have the brake pedal to the floor during any stop also get some pull to one side so yeah. Bottomline is yeah I need to do a deeper inspection on the whole system. I started the thread though as yeah advice on the conversion kits as still thinking of swapping the rear, I yes realize it's more of a looks thing than functionality. Thanks all for the advice.

What I posted to search this site for are the problems others have had with rear disc conventions or other issues.Find out what you issue is and go from there. Here there are others,if I would not know someone else will.There not saying it as personal opinion but as personal experience. They are good. I know somethings not everything.Good Luck!

 

[70chall440]

With a well functioning stock system and modern pads, these cars will stop very well. I have the stock Disc/drum set up on my 70 Challenger which is a PB system and it works well. I have 4 wheel discs on my Cuda which has G2 Viper calipers up front with 12" rotors and 89 Cobra rear calipers and 11" discs on the rear, this is a manual brake system and while it does stop it doesn't throw you forward. I intend to revisit the brakes on this car when I get back around to it.

On the car I am going to build next (71 Charger with a 5.7 and 5spd) I am going to use a hydroboost system. I have done a lot of research on brake systems, built a few of them and I have come to the conclusion that its all about line pressure. Manual and vacuum boosted systems product adequate line pressure for stock brake systems (drum/drum, disc/drum) however they are minimally adequate for a disc/disc application IMO. Some are better than others depending on a variety of factors such as the health of the brake system, size of the rotors, strength of the drivers leg, MC bore size, etc. but in general its a delicate balance in finding the right MC. Many of these systems are individually suited meaning that they are great for one driver and substandard to another.

A hydroboost system (or an electric one) greatly increases line pressure and provides a pretty large degree of performance acceptance in that most would find the brakes to be acceptable because the individual driver could modulate the braking via foot pressure whereas in the more conventional disc/disc systems (manual or vacuum boosted) its depends more on individual driver expectations and acceptance.

In other words going to 4 wheel discs can obviously be done but there might be some concessions that have to be made meaning the car may not stop as desired (but it will look cool).

 

[moparleo]

Like it or not a new Toyota Corolla will out brake a classic 3600lb car every time.
Heavy cars take farther to stop.

 

[bc3j]

I used all Mopar brake parts for my front disc brakes. I have 11” rear drums. I found the Mopar parts work well together. I have manual brakes.

 

[fasjac]

I used all Mopar brake parts for my front disc brakes. I have 11” rear drums. I found the Mopar parts work well together. I have manual brakes.

They do! good choice

 

[Litchkar]

I agree that you should do a through investigation into your system first. Look at shoe to drums for excessive clearance, air and old contaminated brake fluid. Your car is almost 50 years old, who knows what has been done to it. When I got my 71, a previous owner had removed the rear self adjusters. Don‘t assume, check every part out.