Manual brake system parts interaction.

BudW

Moderator
Staff member
Joined
Mar 4, 2012
Messages
5,121
Reaction score
1,485
Location
Oklahoma City
The C-body booster confuses things – so I “X”ed out.

I have found no good pictures of a manual brake master cylinder vs. Power brakes – so I used and modified your picture.
brake-stepup-linkage-B.jpg

The Red is push rod. The Blue is location where master cylinder should be located at – which is a couple of inches lower than power master cylinder is at.

If your car has a cast iron master cylinder – it will be worth the weight loss to convert to an aluminum master cylinder (if applicable).
I think ’78 was last full year of cast iron and ’80 was first full year of aluminum master cylinders.

I’m fairly sure (but not 100%) that you can get undersize and oversize bore master cylinders as well as same for wheel cylinders.
Other than relocating existing master cylinder to correct holes – I think wheel cylinders would be easier to change out.

My suspicion is the previous owner used a power brake reinforcement plate instead of manual brake one. If so, I would make your own plate – for finding a manual reinforcement plate is not easy to do.
BudW
 

Locomotion

Well-Known Member
Joined
Apr 22, 2012
Messages
147
Reaction score
16
Location
Florida
So the right diagram isn't F-body? I'll have to look if I can lower the M/C for a straight shot. But no time for this weekend. I'll just try the bigger M/C and see what happens. Previous owner already had the aluminum version. I'm going from Cardone car 10-1821 1.03" to a Cardone truck 10-1860 1.125"
 

DCAspen

Well-Known Member
Joined
Sep 27, 2011
Messages
1,420
Reaction score
337
Location
ct.
F Body manual brakes have a plate on the firewall to mount the master cylinder so the pushrod goes into the interior to the brake pedal.
101_0029.jpg
101_0030.jpg
 

BudW

Moderator
Staff member
Joined
Mar 4, 2012
Messages
5,121
Reaction score
1,485
Location
Oklahoma City
So the right diagram isn't F-body?
There are two pictures side by side. The picture on Right (that I marked off) is for C-body and they have more space under the dash than the rest of the cars have.
The Left side picture is for B, R, F, M & J-bodies – from about ’66 to ’89.



Something I didn’t think about – but the stiffener plate that DCAspen posted, could be installed upside down.
He took a front and back photos (one with studs down and other with studs up).

A person could install the plate upside down (where studs go into the lower holes when they should be going into the upper holes).
BudW
 

BudW

Moderator
Staff member
Joined
Mar 4, 2012
Messages
5,121
Reaction score
1,485
Location
Oklahoma City
It has been awhile – but the firewall hole is oval-ish and a fairly large hole.
I think a person could get it in there with that stiffener plate upside down, without much trouble . . . I think.
 
Back
Top