New Front End Power Brake Conversion Kit And Upper A Arms Suggestion

[1970GranCoupeCo]

Greetings,

I am just now getting back onto the "Cuda World" after about 20 years so all of my Mopar knowledge is way outdated so I am hoping for a modern education.

I am currently running a front disc/ rear drum/ manual master cylinder system and I want to convert to power brakes and possible updated front suspension system while I am at it so I was hoping to get some suggestions from the Mopar Brain Trust.

I want the "stock" look but am not excessively anal about it but I certainly do not want anything "flashy" or modern looking with cross drilled rotors with red calipers and anodized crap...and...I also do not want to have the "bolt on adapter" brackets for the front discs.

I want to retain the stock ride height and would like some better high speed tracking so I might think about new upper A arms...however...I do not want to go with the polyurethane bushings because the ride quality suffers.

The car has stock 15 inch Rally Rims with firm feel power steering and the longer pitman arm.

The car originally had manual brakes with four wheel drums but the front has since been converted to discs (as I remember from 20 PLUS years ago) it was transplanted spindles and discs out of a 1973 barracuda (but not totally sure now). The master cylinder currently installed is the unit that has the large reservoir for the front discs and a smaller reservoir for the drums (see picture).

So I bought the Inline Tube conversion kit but I am rethinking moving forward with this system 1971-1974 Mopar B-body, 70-74 E-Body, Disc Brake Upper Conversion Kit because I tried to install it however the six holes on my firewall do not match the holes on the replacement bracket. So either they sent the wrong bracket or it will not work for my car. I am waiting for a call back from tech support.

The system did not come with any instructions so I do not know how to connect up the linkage...IF...I figured out how to bolt the brake booster to the firewall.

Now that I go online I see that there are a couple of different systems available.

The Inline Tube system uses a black "Bendix Trapezoid booster" and that "looks stock" and it bolts up the booster and the master cylinder in a straight line with the brake pedal pushrod and then I see other units advertised have a dual brass colored booster that is mounted on a bracket that moves the master up and forward so it is no longer inline with the brake pedal pushrod.

Master Power Brakes® - Brake Booster/Master Conversion Kit

Plymouth Barracuda 1970, Brake Booster/Master Conversion Kit by Master Power Brakes®. With prime disc brake conversion kits, why would you look elsewhere? CARiD offers a host of model specific brake kits and components by Master Power Brakes.

www.carid.com

What is best/ advantages/ disadvantages?

Are there stamped upper A arms available that increase the caster of the front end and look stock or do they have to be the tubular ? If so do you have a recommendation?

Any help and advise is greatly appreciated as I am just now starting to get back into my Barracuda after about 20 years.

THANKS,

Bill

 

[Chryco Psycho]

Scarebird can do a decent up grade using common parts .
But you already have discs , you can go to the Cordoba rotors , 11.75" & use the same calipers , DR Diff has the conversion mounts to move the calipers away for the larger rotors .
The real issue you are struggling with is the booster , most of the weird looking boosters do not seem to do a good job in my experience , stock seems to be the best , go figure ! What I would recommend is Hydro boost , at least look into it , far better braking power without being vacuum dependent assuming you have power steering .
You can add the Moog offset bushings to the stamped upper control arms & increase the caster significantly that way just be careful installing them because the instructions included reduce caster !

 

[1970GranCoupeCo]

Thanks Chryco for the advice

 

[ChallngeAccpted]

I agree with 70grancoupe, stock boosters are best. My brother put on one of those aftermarket disc brake conversion kits onto my challenger with some funky booster (I want to say it was CPP?) Anyways, I hae left it on for the time being but plan to get an original booster and rebuild it someday. As far as your suspension, you said you would like some " some better high speed tracking." Are you actually planning on going on a real track? or just some spirited back road driving? Because when my Challenger belonged to my brother, he couldn't afford the tubular arms from QA1 like I recommended to him since I had them on my 68 Barracuda, so we rebuilt his stock arms. I have to say the car pretty nice. Fresh bushings and an alignment goes a long way on these old cars. I actually like the way my car handles so much that I scratched my idea of going all tubular and decided to keep my rebuilt suspension and just add PST's 1.03 T bars and some super stock leafs. Hope this helps?

 

[1970GranCoupeCo]

I never plan on going to the track. The car has all new rubber bushings (not offset) and it tracks just OK so I was hoping to get a little more caster.

I went with the Bendix unit but it was confirmed that it will not adapt to the firewall so I sent it back.

Mancini is advertising a unit and its instructions show my style firewall plate so I might give it a go

 

[Chryco Psycho]

Moog K7103 is the offset upper bushing , $30 from Rock Auto
you need to install them so the front of the control arm is moved away from the body & the rear is moved inward.
If you use a stock Booster you will need the linkage adapter to increase pressure as well .

 

[Pistolgrip496]

Checkout Firm Feel I updated my complete suspension with there parts.
I used Dr. Diff for the brake system.
great customer service from both.

 

[Ron-B-Cuda]

I tried to install it however the six holes on my firewall do not match the holes on the replacement bracket. So either they sent the wrong bracket or it will not work for my car. I am waiting for a call back from tech support.

Dear 1970 Gran Coup,
Yes, I had the same issue last summer. Oh, Tech Support never called back; I called them a half dozen times.

Anyway, I removed the bracket, drilled new holes, and crawled under the dash to Dremel the holes so the new system could be mounted. An afternoon job became a two week project. Very frustrating.
Then, the weather got cold, so, i don't know if the brake system actually works. This Saturday, we're forecasted for 64 Degrees; warm enough to test drive the (Ops Check) the new rake system.

Please let me know if you have any questions.
Best of luck, Ron

 

[1970GranCoupeCo]

I tried to install it however the six holes on my firewall do not match the holes on the replacement bracket. So either they sent the wrong bracket or it will not work for my car. I am waiting for a call back from tech support.

Thanks Ron for the information.

I am still trying to finalize the vendor for the conversion kit.

When I did in I will report back.

 

[1970GranCoupeCo]

Hi Guys,

I am STILL banging my head against the wall on this upgrade...The "Benxix" style dual diaphram booster has a longer (front to back) dimension and it moves the master cylinder so far forward that it hits the stock cruise control unit so that is a no go.

Can someone PLEASE direct me to the proper source for the following:

-Single "pancake" style booster
-Master cylinder (my current master has a large sized reservoir and a small reservoir as seen in the picture)
-Under dash linkage to adapt the brake pedal to the booster.

THANKS for your help!!!

 

[340challconvert]

I picked up a Wearever Booster Part number 54-73701. It was a remanufactured unit that was an exact match to my original. I paid the core charge to keep my original to eventually re-build. $79.00 at the time (it has been several years)

 

[340challconvert]

This may help; a factory diagram.

 

[1970GranCoupeCo]

Thanks for the information!!!

The Ram Man (Don't forget the INC) wanted $775.00 for the booster and $995.00 for the master cylinder so after the ride in the ambulance to the ER and some nice people yelling "clear" the beep beeps and the squiggly line on the monochrome TV screen started again.

I went to Rock Auto and got the Cardone 5473701 (54-73701) booster and the Centric 13063055 master cylinder and will give it a try.

On the original failed attempt to install the Bendix dual diaphragm booster with the hemi style extension bracket I forgot to include the linkage in the box so I still have the linkage to connect the booster to the brake pedal lever so hopefully it will fit...stay tuned...

 

[340challconvert]

Thanks for the information!!!

The Ram Man (Don't forget the INC) wanted $775.00 for the booster and $995.00 for the master cylinder so after the ride in the ambulance to the ER and some nice people yelling "clear" the beep beeps and the squiggly line on the monochrome TV screen started again.

I went to Rock Auto and got the Cardone 5473701 (54-73701) booster and the Centric 13063055 master cylinder and will give it a try.

On the original failed attempt to install the Bendix dual diaphragm booster with the hemi style extension bracket I forgot to include the linkage in the box so I still have the linkage to connect the booster to the brake pedal lever so hopefully it will fit...stay tuned...

The costly booster and master brake cylinders are for people who must have original units with matching numbers and date codes. The brake cyl. with the 2229171 cast # is like gold.
My booster purchase was also a Cardone 5473701 as well as a Centric Master 130.63055. The Centric Master is a 1 1/8 in. bore size where the original 171 unit was a 1 in. bore. It will work fine.

 

[1970GranCoupeCo]

OK...STILL banging my head on this conversion so I am asking for a life line from the pros...

The back story...the car is a 1970 Barracuda California ordered car built in Hamtramck September 1969 (if that matters). It was originally a manual 4 wheel drum car and in the past I converted it to a manual master cylinder and front disc / rear drums.

I have tried two of the bolt on conversion kits that are available and the trouble I had was that the "Bendix Dual Diaphragm booster" moved the master cylinder too far forward to the point where the master cylinder would conflict with the stock cruise control servo and same thing with the "Hemi" style kit that has a mounting bracket that was positioned between the firewall and the booster and this bracket moves the master cylinder up and forward and that also conflicted with the cruise control servo.

So I thought I would go with a stock-ish 1970 system sourced from Rock Auto and the parts look like the system in the service manual PY367 diagram above in this thread.

The 1970 power booster has a large diameter pushrod rubber bellow so I thought I could simply cut out the center hole of the original manual brake reinforcement bracket and then it would be a "bolt on" deal...nope the studs of the booster will mate up with the holes on the reinforcement bracket except that the holes are not the same configuration as the firewall.

The first picture is the reinforcement bracket placed on the firewall...the picture is not the best however the two top row holes of the bracket slide over the two firewall studs and then the bottom four holes of the bracket and the firewall all line up...that is how the original manual master cylinder bolted on.

The second picture shows the reinforcement bracket placed over the studs on the booster...the two top studs of the booster will not fit on to the top row of holes of the bracket but will instead fit into the second row bolt holes but the firewall does not have any holes drilled into it for these two booster studs...

My firewall has two studs sticking out and they are for two metal clips that hold the wire bundles.

So I was going to drill the two holes however if I did then it looks like the steering column support bracket (the same bracket that the brake pedal bolts to) has a bend in the bracket that will possibly interfere with the nuts used to secure the booster to the fire wall...then if I did get that far the next question will be ...will the brake linkage "lever assembly" bolt up?

Is it possible that there was a different booster used on this car (1971 perhaps)?

The service manual definitely shows the top booster studs being inserted into the top two holes on the firewall and the reinforcement bracket and if I did this then I would need to drill two more bottom holes...

Did Mopar use the same steering column support bracket and firewall holes for the power booster cars and the manual master cylinder cars? It just seems odd that the holes are not lining up.

Has anyone else performed this conversion and had the same issue?

THANKS for your help!!!

 

[1970GranCoupeCo]

Here is a service manual picture that shows the two studs on the firewall for the top two holes of the reinforcement bracket however the cutout on the firewall does not look the same as my car so it must be a B Body

Does other cars have the top two studs and if so do they attach a wire clip?