Installing Hydroboost and bigger brakes in a 1970 Charger

[Kern Dog]

Manual brakes. Power brakes. Vacuum booster with engine as a vacuum source. Vacuum booster with an electric pump as a source.
There are many ways to skin this cat.
Hydroboost? I'd heard of it but never saw the need. I had good luck with manual MC disc drum A body cars. I've had a few power brake A bodies too. They always stopped well. They instilled confidence like a new car does.
My Charger (Ginger) hasn't given me the confidence that I've had with the lighter and simpler Darts and Dusters I've owned despite several combinations that I have tried.

Here is a little history.
The car was built in December 1969 as a 318-904-8 1/4" axle car with 4 wheel 10" drum brakes. It stopped okay but wasn't great.
Within a few months of ownership, I swapped in 11" discs, power booster and master cylinder from a 75 Dart. It was junkyard tech....I cleaned the stuff up but it was all still 1975 vintage stuff.
Braking improved but it wasn't as great as the A body cars due to the increased weight.
In 2004, I swapped in larger 12" rotors but kept the same calipers. If there was an improvement, it wasn't much.
In 2006, I pulled the rear drums and swapped in an 11.7" rear disc brake kit from Dr Diff. This was almost entirely for cosmetic reasons. The 10" drums looked tiny behind the large wheels I have, The braking was about the same as it was with the drums.

 

[Kern Dog]

In 2012, I started thinking that a manual master cylinder setup might give me some better braking "feel" so I pulled the Dart power booster and iron master cylinder. This resulted in a weight savings of about 12 lbs.
I tried 4 different master cylinders and they all delivered the same performance: Hard pedal that barely moved and brakes that couldn't lock up even on a dirt road. I tried an 1 1/8", a 1 1/32", a 15/16" iron and a 15/16" aluminum master cylinder and they all sucked. In defeat, I put the power stuff back on and resigned myself to just live with this combination for awhile. Awhile later I noticed that I had a disc/drum proportioning valve in the system. Four wheel disc systems usually don't need a proportioning valve.....the caliper sizes determine the proportioning like a 4 wheel drum system does with wheel cylinder sizes. I swapped in a drum-drum distribution block and braking improved slightly.
Months later I read about pedal ratio. I took a spare brake pedal and drilled a hole above the stock one. This one change made a noticeable difference. The braking was now between good and great. That was 8 years ago.

I am currently finishing up on an engine rebuild and a brake overhaul with this car which is also being covered elsewhere on the forum.

Re-Rebuilding the 440-493 in a 1970 Charger

For the sake of future searches, I'm going to cover the braking upgrades here in this thread. In my experience, threads that cover multiple topics can get buried and be hard to find specific information later.

 

[BeepBeepRR]

I was looking at a hydroboost setup for the RR but ended up getting a Pirate Jack setup works great..

 

[RemCharger]

Are you talking about a manual pedal?

As far as power brakes go.. how many race cars have power assist brakes

 

[Kern Dog]

The reason that I am jumping in with a hydroboost swap is a bit convoluted. I want to run a bigger cam in the engine and the one I'm using puts out too little vacuum to support the system.
When the 440/493 wiped out yet another cam, I decided to pull the engine and go through it. Through some advice and some research, I believe that this time it was due to the oil that I used.
The Lunati cam I am using was in the engine before and it is still in excellent shape. I pulled it in 2014 because it was a little rowdy for an automatic with power brakes. I now have a 5 speed manual but I needed to do something about the brakes.
First off, I decided to upsize the front rotors.
I contacted Dr Diff and explained my situation. He suggested his 13" "Cobra" kit with twin piston calipers.

It is a nice looking setup. Drilled and slotted rotors....

Billet aluminum hubs.



Aluminum calipers.

You can see the adapter bracket at the bottom. This allows the caliper to attach to the 73-76 A body steering knuckle.

The rear rotors are also drilled and slotted.

 

[Kern Dog]

Are you talking about a manual pedal?

As far as power brakes go.. how many race cars have power assist brakes

How many race cars have air conditioning, a stereo, sound deadening, a console, 4 seats and weigh 4000 lbs?

 

[Kern Dog]

Dr Diff shipped the brake stuff and included a prototype Hydroboost unit for me to test and report on.
Essentially, I am doing the research and development in a grassroots scale.
The HB unit has no identifiable markings but looks great. The Doc included adapter fittings .

The 4 bolt pattern fits the same holes in the firewall. The threaded pushrod is adjustable.

It bolted in easily.

 

[kiwigtx]

 

[Kern Dog]

Backing up a bit, I should have mentioned that these Hydroboost units use pressure from the Power Steering pump to provide boost. This is an excellent workaround for low vacuum camshafts. Diesel vehicles have often been fitted with HB units but many Chevy vans use them as well.
The unit is cast iron and is heavy. You wouldn't choose this route to save weight.
Dr Diff suggested an 1 1/8" master cylinder spec'd for a mid 80s Dodge D-150. Rock Auto....less than $30!

I made new brake lines to fit. This is a tight fit here.

The hydroboost unit complicates matters with the additional plumbing required. The HB gets pressure directly from the power steering pump and there are 3 ports on the HB housing.
The port on the left is input from the pump. The port on the right goes to the power steering unit. The unthreaded fitting is the return.

Since the power steering box has a pressure port and a return line port, a solution has to be found to provide 2 return lines to the pump.

There are several ways to do that. First up, I thought of soldering a nipple to the Bergman return line fitting.

FBBO member 1972GY8SE Mark suggested that I look at a replacement pump reservoir for a vehicle that originally had Hydroboost.
The new ones were out of stock so I went to a junkyard and pulled a Saginaw pump from a mid 90s Chevy 1 ton.

 

[Kern Dog]

Lucky for me, the Saginaw pump "guts" didn't change much from the mid 70s to the mid 90s.
I cleaned up the Chevy pump housing and swapped it all over.

The original from the car. Some call this the "Canned Ham" reservoir:

The Chevy reservoir is larger and looks less like a "Canned Ham" compared to the other one.

Finished product.

 

[Jerry Hall]

The only hydroboost system that I have any familiarity with are the ones on my Dodge Diesels. I look forward to following your project. Thanks

 

[Nxcoupe]

Lucky for me, the Saginaw pump "guts" didn't change much from the mid 70s to the mid 90s.
I cleaned up the Chevy pump housing and swapped it all over.

View attachment 1357302

The original from the car. Some call this the "Canned Ham" reservoir:

View attachment 1357301

View attachment 1357303

The Chevy reservoir is larger and looks less like a "Canned Ham" compared to the other one.

View attachment 1357304

Finished product.

View attachment 1357305

View attachment 1357306

That is amazing that the late model GM pump housing worked with your original brackets.
I did this swap for clearance on another project, now the brakes are super touchy, throw you through the windshield touchy. I'm curious as to what your impression and findings will be.

 

[Kern Dog]

Last Sunday, I set the engine back in. This allowed me to start mocking up the hydraulic lines for the system

With the pump in place, I can now dig in and make some sense of it.

Nobody that I know of makes direct fit lines for this setup. I'm like a blind man in the dark but with some help from a few FBBO members.....
(Thanks Randy and Mark)

I'm working with a local Hydraulic hose and machine shop to come up with lines that will clear the header, tuck close to the body and NOT leak!

 

[Kern Dog]

I am a Carpenter that likes to work on cars so sometimes I run headfirst into projects with no clear plan.....

I can look at most bolts and nuts from these cars and know the size and thread count.
Not so with fittings and such.
This HB unit has these fittings on top.

The ends on the left thread into the HB unit. The other end sticks out of the housing a bit more than I'd like but I'm unable to find something that matches the threads into the HB unit so I could simply run a female thread elbow fitting in there.

Randy suggested these....Funny thing, I bought those just before he suggested them!

I did email Dr Diff. He had a suggestion.....

Banjo fittings? Would these work?

 

[493 Mike]

I just added a return line from a scrap pump I had. Silver soldered it in a "punched" hole. Punched to leave more metal for the soldering/strength. I don't have a close-up photo but, note the 2 caps on the returns. Looks OEM.
Mike

 

[ckessel]

Looking good Greg. See you next weekend in Van Nuys?

 

[dodgedifferent2]

I adapted a hyrdoboost from a 2001 diesel ram truck. Got fitting adapters to AN. Bought an AN line
Made a mount to clock where i wanted the canister. Also made my own pushrod from hydroboost to the 1 1/8 master cylinder off an (80's?) ram truck.

I dont recall the year of truck but i do remember playing on rock auto cross referencing part numbers.

I used the saginaw pump but now planning to hook up to an electric pump power steering pump from a 2004-11 Volvo s40.

 

[NoCar2023]

 

[Kern Dog]

I adapted a hyrdoboost from a 2001 diesel ram truck. Got fitting adapters to AN. Bought an AN line
Made a mount to clock where i wanted the canister. Also made my own pushrod from hydroboost to the 1 1/8 master cylinder off an (80's?) ram truck.

I dont recall the year of truck but i do remember playing on rock auto cross referencing part numbers.

I used the saginaw pump but now planning to hook up to an electric pump power steering pump from a 2004-11 Volvo s40.

How do you like the setup?
I’ve seen them on heavy trucks so I’m guessing that they really provide a lot of boost.
I’m no wimp… I weigh almost 200 and have plenty of leg strength. I just want some “ new car” like habits.
I had a 2002 Ram 1500 that had amazing brakes. You could dive into corners a little too fast and those brakes could scrub off speed real quick. Pedal effort was great too.
I want that.

 

[RemCharger]

How many race cars have air conditioning, a stereo, sound deadening, a console, 4 seats and weigh 4000 lbs?

Touchè! My thoughts started down a different path.