1976 FJ40 South American - Adding Brake Booster, Spacer, 3 Hole Firewall, Conundrum. Can You Identify This Booster/Master Combo?

Ackcruisers

SILVER Star
Joined
Nov 24, 2019
Messages
924
Location
MA
I’m trying to engineer a solution to add a booster w/dual circuit master to my 1976 South American 40 with 3 Hole firewall with single circuit master.

The images below are from a 1976 identical South American 40.

Note the 3 hole master cylinder hole on firewall. (I have no rib to contend with as early models had with this 3 hole master).

35DF9ECD-1716-495D-AB30-D7BD822B1EEE.jpeg

On inside of this firewall, you’ll note the pedal bucket welded to inside of truck. It is not like the US spec pedal bucket.

57F14DF1-E46D-4F1E-A141-3EF2DF2525D0.jpeg

The FJ Company used the below style booster with master. Can you identify this booster/master set up?
53B7EA55-3340-410E-9BB0-F1483F4E9027.jpg

The spacer that is available from several vendors convert 3 hole to 4 hole to accommodate booster bolt pattern but create issues with the distance from firewall to the end of dual circuit master hitting the 2F carb.
6597EF06-285B-4853-8773-4B71B0C72F2A.jpeg

B2B8FDB2-6D48-4043-9207-2D24E55EF3C2.jpeg

Creating a shallow firewall spacer adapter is possible however the booster piston nose diameter is too large to fit into the diameter of the 3 hole firewall hole.

Anyone have a solution?
 
Joined
Jul 5, 2005
Messages
1,685
Location
Ames, IA
Ah, now I see. Yeah that makes it more tricky. I've never seen a little 3 hole booster like that either. Have you called fj company and asked?
 

Ackcruisers

SILVER Star
Joined
Nov 24, 2019
Messages
924
Location
MA
I’ve not asked, but sometimes they chime in. @The FJ Company can you help me and other South American 40 owners (with 1976 3 hole master firewalls) know what booster master was used in this restoration?

See above images or visit this link.

 

lcwizard

Supporting Vendor
Supporting Vendor
GOLD Star
Joined
Dec 5, 2004
Messages
5,016
Location
Miami, Arizona
Website
www.4plusproducts.com
I’m trying to engineer a solution to add a booster w/dual circuit master to my 1976 South American 40 with 3 Hole firewall with single circuit master.

The images below are from a 1976 identical South American 40.

Note the 3 hole master cylinder hole on firewall. (I have no rib to contend with as early models had with this 3 hole master).

View attachment 2893909
On inside of this firewall, you’ll note the pedal bucket welded to inside of truck. It is not like the US spec pedal bucket.

View attachment 2893912
The FJ Company used the below style booster with master. Can you identify this booster/master set up?
View attachment 2893918
The spacer that is available from several vendors convert 3 hole to 4 hole to accommodate booster bolt pattern but create issues with the distance from firewall to the end of dual circuit master hitting the 2F carb.
View attachment 2893919
View attachment 2893920
Creating a shallow firewall spacer adapter is possible however the booster piston nose diameter is too large to fit into the diameter of the 3 hole firewall hole.

Anyone have a solution?
If you're looking for the "cleanest" and foolproof locator, swap pedal buckets with a domestic 40. You can then locate the exact positions of the booster
from the inside of the cab.

IMG_8653.JPG


IMG_8654.JPG


IMG_8657.JPG


IMG_8658.JPG


IMG_8666.JPG
 

Ackcruisers

SILVER Star
Joined
Nov 24, 2019
Messages
924
Location
MA
Looks like there is no easy work around, adapter or bracket that will work to achieve a clean install. After further investigation, any booster converter bracket (regardless of how slim) will interfere with throttle linkage and 2F carb (21100-61012). Red arrow points to linkage.

768EE158-248C-4F5A-A125-F2612AB15ECF.jpeg


The entire pedal bucket assembly for tandem master cylinder (55106-60020) orients the firewall holes to the outside drivers side of firewall by at least an inch.

Thanks for the information @lcwizard. This pulled me out of the rabbit hole. When you removed the single master pedal bucket (55106-60010), was there a total of 4 weld points to cut? Two on bottom (shown below) and two on top of bucket assembly?
806C56B5-F3EB-4E8E-9523-91C15CC9990C.jpeg


This is a larger project than I wanted to tackle but it’s the only way to do it right. I have the bucket and will begin taking everything apart to start the process.

094A6E4A-C885-4E46-9F71-BBDEFC49BBCC.jpeg
 

Jdc1

SILVER Star
Joined
Sep 9, 2013
Messages
4,195
Location
Akron, OH
The F intake manifold mounts the Carb closer to the head allowing space for the master/booster as well. It also looks like the 2GC Sniper might allow master clearance as well.
 

lcwizard

Supporting Vendor
Supporting Vendor
GOLD Star
Joined
Dec 5, 2004
Messages
5,016
Location
Miami, Arizona
Website
www.4plusproducts.com
Looks like there is no easy work around, adapter or bracket that will work to achieve a clean install. After further investigation, any booster converter bracket (regardless of how slim) will interfere with throttle linkage and 2F carb (21100-61012). Red arrow points to linkage.

View attachment 2895326

The entire pedal bucket assembly for tandem master cylinder (55106-60020) orients the firewall holes to the outside drivers side of firewall by at least an inch.

Thanks for the information @lcwizard. This pulled me out of the rabbit hole. When you removed the single master pedal bucket (55106-60010), was there a total of 4 weld points to cut? Two on bottom (shown below) and two on top of bucket assembly?
View attachment 2895331

This is a larger project than I wanted to tackle but it’s the only way to do it right. I have the bucket and will begin taking everything apart to start the process.

View attachment 2895345
There are weld points to cut on the early 40 buckets. The late buckets are entirely bolt in. I haven't done this on the South American
models but I assume the welds will be the same from your pictures. It's a little tedious but in the end you know the holes you cut in the firewall
are correctly placed
 
Joined
Jul 5, 2005
Messages
1,685
Location
Ames, IA
Looking at that FJCompany sa 40 from another angle, looks like they made an adapter for that small booster. Might be 4Runner booster and MC?

i-9nTfgdx-L.jpg
 

3_puppies

SILVER Star
Joined
Dec 2, 2002
Messages
16,097
Location
Helena MT
I like the pedal assembly for the added strength and spreading the load out on the firewall.

does the FJ company install grommets in the firewall holes where the wires run thru?
 

Ackcruisers

SILVER Star
Joined
Nov 24, 2019
Messages
924
Location
MA
I like the pedal assembly for the added strength and spreading the load out on the firewall.

does the FJ company install grommets in the firewall holes where the wires run thru?
The OEM dual master cylinder is very heavy combined with the booster weight. The factory pedal bucket strength looks necessary otherwise there is a lot of weight on three weld nuts.

B650EA5B-CB3D-4F9B-BC28-37A86D57092A.jpeg


The grommets missing all over the FJ Company truck must have been one of their very early heritage restorations. They do have them in their more recent trucks.
 

Ackcruisers

SILVER Star
Joined
Nov 24, 2019
Messages
924
Location
MA
A visual of the 3 hole to 4 hole break booster adapter with booster and tandem master cylinder looks. As mentioned, it would push too far into carb not to mention the diameter of booster would interfere with throttle linkage. It just will not fit.

I feel like I’m in an a special edition episode of FJ40 Myth Busters.

63072EFB-5D22-4AFC-9B97-10FD188B5108.jpeg


E53CF633-5360-452B-B0E1-6660E566566F.jpeg

The length overall measures 15.5 inches. Firewall to end of master.
 

3_puppies

SILVER Star
Joined
Dec 2, 2002
Messages
16,097
Location
Helena MT
looking at this "restoration" of a 1970,
apperently you can just cut the firewall rib and install the booster

\
here is the full ad:

 

Users who are viewing this thread

Top Bottom