Tractor Repair: Ford 641 1958, land contours, draft control

Question
Hi Arnie! Ironically ,Arnie is the name of my deceased father-in law. I just acquired this tractor to service and repair. I am a retired shop owner, 65, (Tate's Auto Service). This tractor is a 1958, 641 (601 series) Ford. There are two small 3/16" rods, one on each side of the seat that are unhooked, not working. Is this the "draft" control? What is draft control anyway? Also on this ohv 4cyl. do you know the compression psi spec?  Thanks Bill

Answer

 Hello Bill,  

  Just thought I would let you know I saw a tractor like yours today, so I saw the rods beside the seat that you asked about.  They are the brake pedal locks.  You push down the brake pedals and pull the rods to lock the brakes on for parking.  Then you push the pedals again, and the locks are supposed to release by themselves.  Maybe you figured this out already, but I wanted to let you know.  I have no idea why yours would be unhooked.

                          Arnie


 Hello,

 I can't figure out what the two 3/16" rods are that you mentioned.  I would need more specific info.  Draft control is a feature of the 3 point hitch that allows the hitch to automatically raise up or down to adjust for changing land contours and soil conditions, so it will maintain a uniform working depth with an implement such as a plow.  It senses how hard the implement is pulling, so if your tractor wheels would go down in a dip in the ground, the draft control senses the plow is going too deep because it is pulling harder, so it raises slightly to keep the plowing depth the same.  If the plow would get too high, it will work the same way and lower it slightly to keep the plow depth the same.  The only compression info I can find is the compression ratio of the gasoline engine (7.5:1)  I can't find any PSI specs for a compression test.

                                  Arnie