Disc brake conversion kits

[low_key_T_wp]

Im not sure about the accuracy of the km however its been 2 or 3 years now since the relining. I don't daily the vehicle. It only drives when I need my guy to do repairs and the odd cruise. So not much driving. When it came back from the brakes people it was smooth braking but they did mention my drums doesn't have much "meat" left.

The low pedal pressure feel is slightly spongy then it bites and she stops fine with some very slight shudder, you cant feel it on the steering at this point but can see rhe hood shake.

Harder pressure at low speed the same haopens but higher speeds the entire steering shakes and got to do the brake, release pedal and brake again.

Maybe I need new drums however the cost to bring it in because of the weight makes me want to rather spend the money on an upgrade

 

[Just Carbs]

Hi there. I'm new here. I found this forum researching converting my 4 wheel drum 1970 dodge monaco in South Africa. We call it here the chrysler 383.

Ive had my brakes done at a brake shop by relining the shoes, smoothing the drums as there isn't much life left on them, new double diaphragm power booster and new soft lines.

I have recently experience some bad shudder braking at some high way speeds. The entire steering shakes horribly and the whole front shakes and just doesn't give a smooth braking experience.

Im looking to convert the front to dosc brakes but finding parts in south africa is tough and has to be imported. Most people here have fords and chevys and the mopar stuff seem to be very expensive.

I've ordered off from rock auto and fedex delivers to my door about 2 weeks. Now with the conversion im wanting to do, I'd like to go oem mopar but unsure which parts to actually buy to do the conversion. I've read cordoba discs would work but still unsure as I would like to retain the current spindles drom the drums, so a bolt on disc kit replacing the drums. Any advice would be appreciated. TA

Your braking description does sound like your drums are out of round.
I understand your desire for disc brakes.
But I also think new drums are a good option in your situation. My experience with Mopar drum brakes has been that they generally work acceptable well over a long period of time if they are in good condition.
Sorry about the shipping cost.

I have used the 78/79 Cordoba parts on several Mopar cars with very good success. Offset upper control arm bushings are often needed to get caster/camber set. I don't know if it fits your car.

 

[CBODY67]

Thanks for the comments and additional information.

To me, one issue is that you can have a very similar situation with disc brakes too. I fully understand the shipping cost issue due to your location, but 4 new drums might well be less weight than the full power disc brake conversion kit, booster and all.

Expect new drums to need to be machined as many will become out-of-round just sitting on the warehouse shelfs, boxes warehoused vertically rather than horizontally.

Another issue is that with the limited and sporadic use, "rust" could be accumulating on the drums' braking surface, which can result in two different surfaces the brake shoes contact. It should be light/surface rust that will be worn off with normal braking, though.

Might need to pull the existing drums off and measure them with a brake drum caliper. To check their internal diameter for being the same at all points and also to inspect the braking surface of the drums, too. Then you can compare the measurements to the cast-in "Max Diameter" spec on the outside of the drums.

Just some thoughts,
CBODY67

 

[Big_John]

Im not sure about the accuracy of the km however its been 2 or 3 years now since the relining. I don't daily the vehicle. It only drives when I need my guy to do repairs and the odd cruise. So not much driving. When it came back from the brakes people it was smooth braking but they did mention my drums doesn't have much "meat" left.

The low pedal pressure feel is slightly spongy then it bites and she stops fine with some very slight shudder, you cant feel it on the steering at this point but can see rhe hood shake.

Harder pressure at low speed the same haopens but higher speeds the entire steering shakes and got to do the brake, release pedal and brake again.

Maybe I need new drums however the cost to bring it in because of the weight makes me want to rather spend the money on an upgrade

It's possible you have a cracked drum if they machined them past the maximum diameter. A good shop won't do that, so your mechanic is a little sketchy in my opinion.

Severe shaking doesn't just occur with wear or even warped drums. Yes, you might get some pulsing in the pedal or maybe a little "back and forth" in the steering wheel, but severe shake means a severe problem. If it's suspension, it's not going away when you change to disc brakes.

It could also be a loose wheel or even a loose or bad wheel bearing.

Whatever the problem is, I strongly suggest you find it before you waste a bunch of money changing to disc brakes and the problem is still there.

 

[low_key_T_wp]

Your braking description does sound like your drums are out of round.
I understand your desire for disc brakes.
But I also think new drums are a good option in your situation. My experience with Mopar drum brakes has been that they generally work acceptable well over a long period of time if they are in good condition.
Sorry about the shipping cost.

I have used the 78/79 Cordoba parts on several Mopar cars with very good success. Offset upper control arm bushings are often needed to get caster/camber set. I don't know if it fits your car.

Thank you for your reply. I will look into the drums as a solution as I don't drive too much.

 

[low_key_T_wp]

It's possible you have a cracked drum if they machined them past the maximum diameter. A good shop won't do that, so your mechanic is a little sketchy in my opinion.

Severe shaking doesn't just occur with wear or even warped drums. Yes, you might get some pulsing in the pedal or maybe a little "back and forth" in the steering wheel, but severe shake means a severe problem. If it's suspension, it's not going away when you change to disc brakes.

It could also be a loose wheel or even a loose or bad wheel bearing.

Whatever the problem is, I strongly suggest you find it before you waste a bunch of money changing to disc brakes and the problem is still there.

It's possible you have a cracked drum if they machined them past the maximum diameter. A good shop won't do that, so your mechanic is a little sketchy in my opinion.

Severe shaking doesn't just occur with wear or even warped drums. Yes, you might get some pulsing in the pedal or maybe a little "back and forth" in the steering wheel, but severe shake means a severe problem. If it's suspension, it's not going away when you change to disc brakes.

It could also be a loose wheel or even a loose or bad wheel bearing.

Whatever the problem is, I strongly suggest you find it before you waste a bunch of money changing to disc brakes and the problem is still there.

Thank you for responding. I didn't think of bad bearing or anything loose actually. The brakes people are the ones that messed me around. The was starting etc when it went to them. Got it back dead.

My mechanic is the guy who is responsible for getting my land yacht back on the road and he does most maintenance for me. He hasn't touched my brakes yet and i should have him check it out asap

 

[low_key_T_wp]

Thanks for the comments and additional information.

To me, one issue is that you can have a very similar situation with disc brakes too. I fully understand the shipping cost issue due to your location, but 4 new drums might well be less weight than the full power disc brake conversion kit, booster and all.

Expect new drums to need to be machined as many will become out-of-round just sitting on the warehouse shelfs, boxes warehoused vertically rather than horizontally.

Another issue is that with the limited and sporadic use, "rust" could be accumulating on the drums' braking surface, which can result in two different surfaces the brake shoes contact. It should be light/surface rust that will be worn off with normal braking, though.

Might need to pull the existing drums off and measure them with a brake drum caliper. To check their internal diameter for being the same at all points and also to inspect the braking surface of the drums, too. Then you can compare the measurements to the cast-in "Max Diameter" spec on the outside of the drums.

Just some thoughts,
CBODY67

Drums sees to be my best option. It hasn't failed me since so will get some quotes to have it imported thru a company or do it myself but value added tax and import duties in south africa on car parts is also high. Damned either way haha.

I'll also look into the other bits about the suspension and bearings

 

[71Polara383]

Post pics of your 383!

 

[low_key_T_wp]

Post pics of your 383!

 

[Northern Australia]

Finding and using used factory disc brake parts, competently rebuilt, will provide a much more ROBUST braking system than ANY aftermarket kit. Check other threads in here for what to look for/get.

The ONE plus for Wilwood is their longevity in business. I remember when they first appeared on the drag racing scene with disc brake kits for drag cars. At the time, their components seemed "small" compared to factory OEM parts. That is their heritage. In brakes, "don't want small", to me. BUT we also know that as the cars age, fewer will be around so fewer parts from the auto supply people as sales volumes decrease. One observed issue with the Scarebird/"will fit" kits using OEM parts sourced from auto supply vendors.

There will always be caliper kits and calipers around in the aftermarket, but rotors are a different situation. In one respect, a "kit" which would use the factory hub, but have rotors which slide onto it rather than a brake drum might be a good approach. Then figure out the mounting for a GM single-piston caliper (with D52-style pads) and you're done.

Now, things can get a bit blurry on the issue of power boosters. Chrysler put a dual-diaphram unit with the earlier power disc brake systems. In later years (fuselage), a single diaphram of a larger diameter. Might play that part by ea?

NO real need for disc brakes unless you plan on towing or drive in the mountains. But then again, Chrysler put wider shoes and drums on their two packages from the factory. YET, more heat-tolerant brake linings are available for normal-width brakes.

Just some thoughts and observations,
CBODY67

I have been surprised how good the American chrysler drums were even in 1969... I have also entertained the thought of a conversion kit, only because more modern cars use disks, and the local Australian drums were pretty rubbish.. But my 69 Newport stops just fine, and even the state mechanic during a registration check said the brakes are great... There are even reports that modern electric vehicles are looking at reviving drum brake technology....

 

[Big_John]

I have been surprised how good the American chrysler drums were even in 1969... I have also entertained the thought of a conversion kit, only because more modern cars use disks, and the local Australian drums were pretty rubbish.. But my 69 Newport stops just fine, and even the state mechanic during a registration check said the brakes are great... There are even reports that modern electric vehicles are looking at reviving drum brake technology....

You have to remember that NASCAR used drum brakes on the 200MPH stock cars, albeit huge ones, until 1975.

Most of what I see when people ask about disc conversions is one of two things. One is the drum brakes on the car are somehow screwed up or just worn out and the owner either doesn't know how to repair or their "mechanic" is suggesting it. The other is this "gotta upgrade" mentality that seems to become more and more prevalent in the hobby. Not everything you can change is an upgrade, especially when you are bolting on some POS kit that uses undersize discs and generic GM based master cylinders and boosters that don't fit right.

Do it right, with good parts that are large enough to do the job and fit correctly or use what the factory used. It seems simple to me and it's a good mod then.

What's really funny to me is back when disc brakes first came out, there were mechanics (both pro and backyard) who wouldn't touch disc brakes. Now there are guys that won't touch drums!

 

[Northern Australia]

You have to remember that NASCAR used drum brakes on the 200MPH stock cars, albeit huge ones, until 1975.

Most of what I see when people ask about disc conversions is one of two things. One is the drum brakes on the car are somehow screwed up or just worn out and the owner either doesn't know how to repair or their "mechanic" is suggesting it. The other is this "gotta upgrade" mentality that seems to become more and more prevalent in the hobby. Not everything you can change is an upgrade, especially when you are bolting on some POS kit that uses undersize discs and generic GM based master cylinders and boosters that don't fit right.

Do it right, with good parts that are large enough to do the job and fit correctly or use what the factory used. It seems simple to me and it's a good mod then.

What's really funny to me is back when disc brakes first came out, there were mechanics (both pro and backyard) who wouldn't touch disc brakes. Now there are guys that won't touch drums!

I reckon the drums are fine, and I'm not going to change them... I don't quite get up to 200 mph. I just have a 383-2 but it still keeps up with the locals in the outback and will cruise at 100 mph all day long... I am also lucky enough to have one of the last 300s with the 392 Hemi (6.4 litres in the local currency), but my preferred daily driver is the 69 Newport...

 

[customsportsman]

What Big John said in post #71!! 100%!

 

[edbods]

I reckon the drums are fine, and I'm not going to change them... I don't quite get up to 200 mph. I just have a 383-2 but it still keeps up with the locals in the outback and will cruise at 100 mph all day long... I am also lucky enough to have one of the last 300s with the 392 Hemi (6.4 litres in the local currency), but my preferred daily driver is the 69 Newport...

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Damn, never thought I'd see a classic in NT of all places. Every now and then I go window shopping on carsales or even facebook marketplace and don't find much in NT. How much do you end up paying for rego with the displacement tax? Can't suppose it'd be any higher than in NSW...
People tend to think drum brakes are inferior to discs, but that's just in the cooling department. They actually have more stopping power but just suck at getting rid of the heat. I've got a disc brake conversion kit sitting in my room waiting to be installed, and really the primary reason I'm getting them is because I plan to do some hard mountain driving with it, and the brake pad pattern these calipers are using just so happen to have EBC bluestuffs available.

 

[Northern Australia]

Damn, never thought I'd see a classic in NT of all places. Every now and then I go window shopping on carsales or even facebook marketplace and don't find much in NT. How much do you end up paying for rego with the displacement tax? Can't suppose it'd be any higher than in NSW...
People tend to think drum brakes are inferior to discs, but that's just in the cooling department. They actually have more stopping power but just suck at getting rid of the heat. I've got a disc brake conversion kit sitting in my room waiting to be installed, and really the primary reason I'm getting them is because I plan to do some hard mountain driving with it, and the brake pad pattern these calipers are using just so happen to have EBC bluestuffs available.

Hey Edbods - I think you're right. I don't see too many classic cars up here. There are a few Aussie classics, but not so many North American vehicles... The rego is pretty high because it is worked out on displacement up here too... But overall it is okay because I don't drive it much in wet season, but use it all throughout the dry season.... Nice to hear from you and I appreciate your knowledge of drum brakes... To be fair, I rarely use the brakes at all driving on the Stuart Highway - it is pretty much all accelerator action !!!!