1963- Riviera dual master brake cylinder conversion for drum brakes

[OldGerman]

Hello Jim, Jon,

 

Thank you for your reply.

That makes all sense. Possibly I'm to much used to Disc/Drum equiped vehicles.

 

Did you ever disassembled the GM style DRUM/DRUM MC ?  

What is the internal setup ?  Dual piston ?

 

My initial thought was that the rear part of the master cylinder, the primary cylinder "comes first" when it generates the pressure.

(see attached typical Bendix Dual Mayster Cylinder disassembled).  But it maybe should be connected this way because of the fail safe function.

The pressure should be the same, at primary and secondary, right ?

[steelman]

Frank, if you want to make the change, you can add an adjustable proportion ing valve. It has a dial that will adjust bias from front to rear. Several available, even on Amazon, so shipping to Germany may be easier than through a retailer like Summit.

https://www.amazon.com/Proportioning-Universal-Proportional-Adjustable-150PSI‑1200PSI/dp/B08Q7PMNSB/ref=asc_df_B08Q7PMNSB/?tag=hyprod-20&linkCode=df0&hvadid=539594636305&hvpos=&hvnetw=g&hvrand=2475511726919005818&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=9026274&hvtargid=pla-1428114610226&psc=1

[XframeFX]

Frank, I can't remember the internals. Mixed-up with other projects where we use Corvette MCs with 2-Large reservoirs.

 

Key is to use an MC with the deeper piston pocket, 1.625" for Bendix. Should not need to adjust your pushrod.

1964 Cadillac used an MC with equal size ports (below).

1967 Riviera used different size ports (bottom).

They don't identify which are primary/secondary ports. So, I prefer the Cadillac MC where both are 1/2"

As Jim mentioned. "It is what it is". The question is if the brakes are restored to back to normal design (before your conversion where the rears locked-up as well)

If in your opinion, the situation is not satisfactory, something is wrong.

I have not pushed my '63 brakes to experience rear Lock-up. Happy so far.

[OldGerman]

On 9/30/2022 at 2:31 PM, steelman said:

Frank, if you want to make the change, you can add an adjustable proportion ing valve. It has a dial that will adjust bias from front to rear. Several available, even on Amazon, so shipping to Germany may be easier than through a retailer like Summit.

https://www.amazon.com/Proportioning-Universal-Proportional-Adjustable-150PSI‑1200PSI/dp/B08Q7PMNSB/ref=asc_df_B08Q7PMNSB/?tag=hyprod-20&linkCode=df0&hvadid=539594636305&hvpos=&hvnetw=g&hvrand=2475511726919005818&hvpone=&hvptwo=&hvqmt=&hvdev=t&hvdvcmdl=&hvlocint=&hvlocphy=9026274&hvtargid=pla-1428114610226&psc=1

Have this one installed for the rear circuit, thanks. It is good to limit the pressure up to 70%. 

Edited October 2, 2022 by OldGerman
Added picture (see edit history)

[OldGerman]

On 10/1/2022 at 1:12 AM, XframeFX said:

Frank, I can't remember the internals. Mixed-up with other projects where we use Corvette MCs with 2-Large reservoirs.

 

Key is to use an MC with the deeper piston pocket, 1.625" for Bendix. Should not need to adjust your pushrod.

1964 Cadillac used an MC with equal size ports (below).

1967 Riviera used different size ports (bottom).

They don't identify which are primary/secondary ports. So, I prefer the Cadillac MC where both are 1/2"

As Jim mentioned. "It is what it is". The question is if the brakes are restored to back to normal design (before your conversion where the rears locked-up as well)

If in your opinion, the situation is not satisfactory, something is wrong.

I have not pushed my '63 brakes to experience rear Lock-up. Happy so far.

Thank you for reply, John.

I have a 63 with Moraine booster (not a Bendix). 

Just took a bendix MC for internal Setup for reference, I did not find any specific of my MC. 

I don‘t know the Brand, it was part of the POL kit. 

Outlet ports should point to the left, and it has a 1“ push rod depth and 1“ piston diameter. 

 

Thanks.