Looking for a firm brake pedal

-
tekslk

tekslk

Well-Known Member
Joined
Dec 13, 2009
Messages
3,140
Reaction score
95
Location
McClure, Pa
My 9 inch brakes worked as good as they could I switch to 10 all the way around and now it seams like it takes more pedal to stop. All air is out of lines, Im just wondering what I can do to get the firm pedal feel back. Possibly master cyl, manual brakes. I dont understand the diff between the diffrent bore or rod size so be patient with me. Dont get me wrong the 10 inch brakes stop the car they just dont have the feel Im looking for.
 
How far do you have to push the peddle before you feel anything?
 
You need to decide if this is "pedal movement" before a firm pedal or just lack of a firm pedal

Cylinder............master..........sizes

Think of it as a lever, a crowbar. If you stick a crowbar of a given length (your brake pedal) under a rock at one end (the brake shoes) and put a fulcrum under the bar to pry against, the length of the bar between the fulcrum and the load getting longer will make the load harder to move. Likewise, making the bar on your side of the fulcrum longer makes the load EASIER to move but you have to move the bar FURTHER at your end to get much movement at the FAR end

Same thing with cylinders and master

As you make the cylinder bores larger, or the master smaller, the pedal must move further, but will require less foot pressure to provide a given stopping force.

Likewise, making the cylinder bores smaller, or the master larger, the pedal will not depress as far, but will require more foot effort
 
I tend to agree with what you said, How do I make the bores smaller or the master larger I think I like to step harder on pedal but not as far. Does this require a diffrent master cyl or what, and how do I no what to get?
 
I push pedal down about half way and you can feel brakes are working, I only had to go about 1/4 the way before, so how do I get it back to that feel again. Brakes have been adjusted also.
 
Yup. Have to change the master. As I said, though, you need to determine if this is simply changed piston stroke, or whether it's a spongy pedal due to air, or other trouble.

In my own case, I went from the factory non power 9" drums on my 67 KEEPING the original master until I found out "whut," and now have 4 wheel discs............

73/4 style on the front, and Lincoln Versaille on the rear. The pedal moves about 40% or so of full stroke, is nice and firm, and stops like nobody's business.

This master DOES have rather small "tanks" so I'll have to keep an eye on fluid. Probably once a year..........check it.
 
Im postive this is piston stroke how do I know what to buy so I dont get the same thing. Or that I buy the one that will give mefirmer pedal?
 
The only thing that I know that was changed that might affect the pedal would have been the wheel cylinders, now we have to try to make a diffrence up top if anyone nos how to cure just chime in.
 
Since you upgraded to 10's in my opinion you may as well upgrade the MC and a couple other things as well. Get a nice aluminum MC and 2 to 4 bolt adapter. Much lighter and grat pedal feel! Which one? Rock Auto, get one for an early 90's B100/150 van. Then get the adapter and better rear wheel cyl's from Rick Erehnberg on Ebay! All under $100 easy, and you'll be surprised at the difference and improved brake performance and feel! Got this setup on my Duster (with discs in front tho) and love it....have had this setup on all 3 of my A bodies and it's always been great for a manual brake application! Even my crap 9" drum Dart was better with the aluminum MC and wheel cyl's!
 
Sounds to me like you are doing a lot of guessing.

The real answer is, you need to find out what you are starting with. If you are absolutely certain that it has the original cylinder, look it up and find out what the bore is, and if you can't then pull it off far enough that you can stick a caliper in the back and measure it.

Or if you know the year/ model which the 10 inchers came off of, buy a master to fit that application
 
Ive seen 7 and 8 inch booster and master cylinder on ebay to upgrade me to power brakes I think thats the way I will go for now than disc later.
 
sounds like a good power bleed would give more answers or solve the problem, sounds like you got some air in there somewhere yet
 
Rockauto gives the bore diameters of most of the MC's they list. The first thing I would look for in "lost motion" is whether the shoes are adjusted correctly. If you assembled the self-adjusters correctly, and they work, you can back up and stop hard many times to make them adjust. That is the first thing I do after a drum brake job and it has always greatly lessened the pedal travel. I always install with the shoes not touching, since I don't want to risk dragging brakes.
 
You must log in or register to reply here.
-

Back
Top