Frame mounted power brakes.

[Old Fire Guy]

Has anyone used the universal frame mounted 7-inch power brake unit offered by Pirate Jack?  I'm thinking about using it on my '49 DeSoto S-13, over a firewall mounted unit. Any thoughts or experiences?

[James_Douglas]

18 hours ago, Old Fire Guy said:

Has anyone used the universal frame mounted 7-inch power brake unit offered by Pirate Jack?  I'm thinking about using it on my '49 DeSoto S-13, over a firewall mounted unit. Any thoughts or experiences?

 

 

On my 1949 Desoto CV, I used the ECI front disc conversion. On the rear, I designed and made one myself. I am using a stock c.1951 single master cylinder with that pedal (the ratios were different between power and none power cars)  and a trunk mounted midland-Ross remote power brake booster (Chrysler 1960-1964 RAM Induction cars or 1955-1957 T-Birds). The brakes are TOO strong. Like driving a 1960 Chrysler.

 

If I were to do it again, and I will on my 1947 Desoto Suburban, I will use a dual master cylinder with the disc fronts and rear, but I will use the wilwood two piston calipers that one can use in place of the basic GM units. Less pedal effort with the two piston units. I will however make sure I have clearance for a booster like the one you show if it is not enough for the Suburban at 5500 pounds.

 

 

 

James.

[Plymouthy Adams]

James, the weight you class your suburban in is very high compared to the factory shipping weight as listed at 4012 lbs.....are you going on gross weight, all passenger and luggage?  

[Old Fire Guy]

I put my DeSoto back on the lift and immediately noticed the transmission (727) cross member (fabricated) would be in the way, which may not be an issue if I swapped the 727 for an A-518 OD trans as the cross member would have to be moved back anyway. I need to do some measuring.

[Adam H P15 D30]

Yup, have one in my 47.  You can see the bracket in the picture.  I trimmed the frame mount down a little in the front and welded it on, bolted the brake assembly bracket to it.  Works good, clears the 518 crossmember.