There are two brake pedals one for each back wheel. When required to turn sharply, you can use the brake pedal on the left for instance, to assist in a turn hard left. Same for the other brake pedal. The latch is used to stop the tractor during normal driving activities, by hooking the brake pedals together creating, in essence, one brake pedal so that the two back wheel react together stopping the tractor without pulling from one side or the other.
You seem to have a seized left brake. Check the linkage to the wheel to see if something is rusted together or jammed up some how. If you can't find anything, you end up having to pull the wheel off and get at the brakes.
Have you obtained any manuals on your tractor?

 

There are two brake pedals one for each back wheel. When required to turn sharply, you can use the brake pedal on the left for instance, to assist in a turn hard left. Same for the other brake pedal. The latch is used to stop the tractor during normal driving activities, by hooking the brake pedals together creating, in essence, one brake pedal so that the two back wheel react together stopping the tractor without pulling from one side or the other.
You seem to have a seized left brake. Check the linkage to the wheel to see if something is rusted together or jammed up some how. If you can't find anything, you end up having to pull the wheel off and get at the brakes.
Have you obtained any manuals on your tractor?

I will definitely look into that. So far I didn't buy any manuals or books yet.

Actually I wanted to move it indoors to fix a leaking carburetor but since it had brake problems I didn't dare to try to drive it there

 

Also the right pedal pivots on the cross shaft. The green arrow in your photo starts near that pivot point. The left pedal actually rotates that shaft when depressed. The shaft goes through the tractor clutch housing and can be dry, rusted, stuck, etc and not rotate easily if at all. Try disconnecting the brake linkage on the left side of the tractor and then see how the pedal moves.

 

IF you take care, you can stop the tractor on one brake, just drive like you own it, not like you stole it!
EDIT:
I'm referring to getting it into your shop!!

 

The dual brakes are especially awesome with a gear tranny and a hand throttle for pivoting around on one wheel.

 

In first low pulling into a garage and stopping is a push on the clutch and brake tap. Traveling any distance brake easy. With one brake a hard stop can push the front end too one side

 

It has been discussed what the pedals do. And what the "lever" is for so I won't get into all that. The brakes are drum brakes located just inside the wheels. You stated the left brake is "hard" and does not appear to work. By now I am sure you have checked the linkage and know it is "twisting" the shaft the activates the brakes. Have you inspected the inner wheel and drum for signs of oil or grease?? Often the axle seals leak and of course it leaks on the brake shoes and lubes the shoes and drums. If so the INNER seal needs replaced. Being it 60 years old or so might not be a bad idea to replace the anyway. Remove the wheel, drum, and the axle shaft, look in the axle housing and you will see the seal. There is very little need to replace the outer seal as it is supposed to keep dirt out of the bearing and grease in the bearing housing. Beside it is a big job to replace it. Also jack up the tractor remove both wheels and check the axle end play, It should have none. If you adjust it remove enough shims so both hubs turn the SAME way. Add shims until when one is turned the other turn OPPOSITE direction. Once pedals move freely and all is back together, adjust the brakes by that slot at the back of the brake backing plate. Do not stop until you have both pedals adjusted even. When you latch the pedals together the tractor should go to an even straight stop and not pull to one side or the other if it pulls to one side readjust until they stop evenly. The latch is supposed to be used at high speed so you don't just step on one pedal and roll the tractor as it turns sideways.

 

Your book becomes your best tool for working on your equipment. Not having the book will usually lead to early break downs. These old machines are durable and somewhat forgiving but lack of oil, grease and regular maintenance will cost you. I have seen guys buy an old tractor and just use them until something breaks. Then it costs more.
Kent; They are fairly simple user friendly machines.
Enjoy your tractor

 

MF 200b. just purchased this small dozer. everything works as it should besides the brake wont release on the left side of the machine. when you apply the foot brake the cam shaft that goes through the dry clutch is rusted in good. it will apply but will not release unless you pull it back with a pipe wrench? does the whole final drive unit need to be removed to lube cam up?

 

Why does everyone purchase the half right books when the original can be had for the same price or less?? go to www.agcopubs.com and for the 35 check 651093M93 Parts for the MF35 @31.59 : 690495M3 Operator manual @10.04: 1448811M1 service man @39.65 These are manuals printed by the manufacturer they ought to know more about their products than anyone else. By the way Trigger Bob the manuals for the 200B are 1448994M1 service man @ 41.40 : 1448374M1 Operators Manual @17.37 and 2715980M1 parts @ 46.89. Now that being said you can also go to www.agcopartsbooks.com enter as a guest and look up parts for free. Then go on line and check for the best price and buy. Also you can see how things are assembled.

 

Why does everyone purchase the half right books when the original can be had for the same price or less?? go to www.agcopubs.com and for the 35 check 651093M93 Parts for the MF35 @31.59 : 690495M3 Operator manual @10.04: 1448811M1 service man @39.65 These are manuals printed by the manufacturer they ought to know more about their products than anyone else. By the way Trigger Bob the manuals for the 200B are 1448994M1 service man @ 41.40 : 1448374M1 Operators Manual @17.37 and 2715980M1 parts @ 46.89. Now that being said you can also go to www.agcopartsbooks.com enter as a guest and look up parts for free. Then go on line and check for the best price and buy. Also you can see how things are assembled.

thankyou for that. that will help out a lot. i also was unsure if anyone on here had to deal with a similar probably on a 200b