New to Mopars, disc brake questions

[TroyCo]

Hey all, I just purchased a 66 Polara manual drum car, and I'm gathering parts for a power disc swap. I have been researching the forums and have most of the basics covered, but I just wanted to clarify, do I absolutely need a power brake booster from a 65-68 car for my 66, or will a later 69-73 booster fit with minimal effort? Also, do I need the brake pedal from either the 65-68 and/or the 69-73 power disc car for either booster swap? The Polara does not have cruise, but it is a column shift.
I am looking at a 73 Newport for parts that runs and drives. I am also prepared to retrofit an old hydroboost setup from an Astro I have left over from my GM days as a last resort, but I always prefer factory parts over "custom modifications". Thanks in advance.

 

[Davea Lux]

Hey all, I just purchased a 66 Polara manual drum car, and I'm gathering parts for a power disc swap. I have been researching the forums and have most of the basics covered, but I just wanted to clarify, do I absolutely need a power brake booster from a 65-68 car for my 66, or will a later 69-73 booster fit with minimal effort? Also, do I need the brake pedal from either the 65-68 and/or the 69-73 power disc car for either booster swap? The Polara does not have cruise, but it is a column shift.
I am looking at a 73 Newport for parts that runs and drives. I am also prepared to retrofit an old hydroboost setup from an Astro I have left over from my GM days as a last resort, but I always prefer factory parts over "custom modifications". Thanks in advance.

The manual drum cars use a different brake pedal and mount plate than the power optioned cars. With manual brakes the leverage points are different to get more stopping action with less pedal pressure. The '65-'68 Bendix dual diaphragm booster would be the preferred choice for a disc brake conversion on this car. Drum brakes use a Midland-Ross single clamp booster which is not as powerful. Both the Bendix and Midland Booster use the same mount plate and pedal assembly. My recollection is that the booster from '69-'70 and some '71 models is also a dual diaphragm booster, but I believe the mount flange has a different bolt pattern. The '72-'73 booster is a large diameter single diaphragm booster that has clearance issues with the shift linkage and on some applications, the valve covers and fender struts, so it probably won't fit. If you are converting to single piston calipers, the spindle assemblies from '69-'72 will fit your vehicle. The '73 spindles will also fit but you will need to use the '73 rotors as the bearings are different.
You also need to install an appropriate metering block or proportioning valve as part of the disc conversion. Mopars with disc brakes had a metering block installed at the front cross member in place of the distribution block. If you can't find one of those, an aftermarket proportioning valve is available from several vendors, www.inlinetube.com, among others.

Dave

 

[TroyCo]

Thank you for that information. So what I need to find more than anything is the 65-68 booster and pedal. The later pedals should work too though, right? Or is that only with the matching booster? The plan is to use the single piston calipers. If needed, I already have a spare proportioning valve.

 

[Davea Lux]

Thank you for that information. So what I need to find more than anything is the 65-68 booster and pedal. The later pedals should work too though, right? Or is that only with the matching booster? The plan is to use the single piston calipers. If needed, I already have a spare proportioning valve.

What I would suggest is that you try to find a '66 pedal assembly and mount plate in addition to the booster. The later pedals might fit, but you would need to try it to see if that is the case. The firewall configurations changed some on the later cars.

Dave

 

[Ross Wooldridge]

AFAIK, the later pedal assembly will NOT fit in your 66 Polara. You need a 65-68 C body power brake pedal assembly and mounting plate. Both disc and drum boosters will bolt up just fine, but it is HIGHLY recommended that you get the 65-69 disc brake power booster.

I know from experience that the 70-73 disc brake booster will bolt up fine to your 66 Polara, but since your car is a column shift, you will NOT be able to shift to Low 2 or Low 1 due to linkage clearance with the broader later model booster. Been there done that.

I can provide you with a detailed parts and information list, that if you search around on this forum you'll probably find anyhow.

 

[TroyCo]

What I would suggest is that you try to find a '66 pedal assembly and mount plate in addition to the booster. The later pedals might fit, but you would need to try it to see if that is the case. The firewall configurations changed some on the later cars.

Dave

That's good advice. Thank you.

 

[TroyCo]

AFAIK, the later pedal assembly will NOT fit in your 66 Polara. You need a 65-68 C body power brake pedal assembly and mounting plate. Both disc and drum boosters will bolt up just fine, but it is HIGHLY recommended that you get the 65-69 disc brake power booster.

I know from experience that the 70-73 disc brake booster will bolt up fine to your 66 Polara, but since your car is a column shift, you will NOT be able to shift to Low 2 or Low 1 due to linkage clearance with the broader later model booster. Been there done that.

I can provide you with a detailed parts and information list, that if you search around on this forum you'll probably find anyhow.

Thank you. A lot of the information I've gathered so far has been from your write-ups in the forums. Very informative.

 

[Ross Wooldridge]

Well, don't hesitate to ask any questions that arise - brakes are the single most important system on any car, and if you don't get it right, well...

Have fun!

 

[FURYGT]

Use the metering block/proportioning valve from the '73. Different brake boosters with different shapes were used from 70 - 73 on power disc brake cars and station wagons, at least for some of those years used a different booster. If you buy and take parts off the 73 Newport you could see if the booster from that car creates any interference with the shift linkage.

Here is a link to the single diaphragm booster that was used starting in '71 on disc/drum C Body applications. This is the booster I have in my '68 Sport Fury that I converted to disc brakes and I do not recall having any linkage interference issues.

Bendix Vacuum Power Brake Booster Chrysler #18268 Bendix #12886 | eBay

 

[TroyCo]

Well, don't hesitate to ask any questions that arise - brakes are the single most important system on any car, and if you don't get it right, well...

Have fun!

well, funny you should mention...the booster you pictured in that one thread must be the Bendix style you mention, however the only way I can get that part is if I send in a core. I found this one RockAuto and Amazon as well... will this work?

https://www.amazon.ca/dp/B000C41OWC...wVehicle=1&vehicleId=1&vehicleType=automotive

 

[FURYGT]

well, funny you should mention...the booster you pictured in that one thread must be the Bendix style you mention, however the only way I can get that part is if I send in a core. I found this one RockAuto and Amazon as well... will this work?

https://www.amazon.ca/dp/B000C41OWC/ref=au_as_r?_encoding=UTF8&Make=Dodge|40&Model=Monaco|311&Year=1966|1966&ie=UTF8&newVehicle=1&vehicleId=1&vehicleType=automotive

See my edited post above. Don't buy anything rebuilt by Cardone as you will be replacing it in a very short time IMHO.

 

[TroyCo]

See my edited post above. Don't buy anything rebuilt by Cardone as you will be replacing it in a very short time IMHO.

Good to know. I'll keep my eye on that auction. Turns out the part I listed is for drum brakes anyhow. If that doesn't pan out, does anyone else have any part numbers that may be helpful?

 

[Ross Wooldridge]

Agreed, don't send anything out through the two sources you listed above. Rather, find a proper one from a suitable donor car, and send it out to Booster Dewey (best choice) or John Stuart (Hamilton Ontario) or North American Rebuilders (Oakville ON) for rebuilding.

 

[TroyCo]

Very good. Thanks for that.

 

[TroyCo]

Spoke to Nigel at National MoParts, he's going to hook me up with a conversion kit. Decided not to mess around with a wild goose chase.

 

[Mopar Papa]

Got a 70 Monaco. Changing from drum power front brakes to disc..can you buy conversion kits in Canada or do you have to go state side ?

 

[Ross Wooldridge]

www.nationalmoparts.com is a Canadian company. They'll have a conversion kit for your Monaco

1-800-652-7464

Ask for Nigel.

 

[Davea Lux]

Got a 70 Monaco. Changing from drum power front brakes to disc..can you buy conversion kits in Canada or do you have to go state side ?

The best conversion would be to use factory parts. That means trying to find a salvage yard car. Disc spindles from '69-'72. Dual diaphragm Bendix booster from '68-'70 C-Body. (Some '71 C-Bodies also used the dual diaphragm booster.) Calipers and disk rotors from '69-'72 C-Body. You can also use '73 C-Body spindles, rotors but keep in mid that they are one year only. Calipers were the same from '69-'73. You will also need to install a brake proportions valve to rebalance the brake system.

Dave

 

[Mopar Papa]

Thanks Ross and Dave …

Ross- does Nigel use factory parts? I just check National website and they do have a kit showing …do they make them up? New to this. Thanks

 

[Ross Wooldridge]

Nigel can do both.

I'm with Dave - use factory parts for the best engineered conversion.