Recently I have been having problems with what seemed at first with a brake dragging on the left side of my john deere ct 332. I kept running the thing for up to 45 mins at a time and let the drive cool down because it would get real hot. It got to the point that the problem started to seem like the drive was going because of the screeching and grinding noise so I assumed that that was definitely the problem. I babied the machine back up to the tool shed and proceeded to remove the track and shot straight up to john deere to purchased a brand new drive. Drive came in in a few days, installed it, fired up the machine, turned park brake switch to off, while in idle moved the stick forward, no noise, pulled back on stick, no noise. Reved up to around 2000 rpm grinding noise returns, only the left side. Damn!!!! OK, maybe a clogged line from the park Park Brake Valve Manifold. Took two days and a whole lot of labor to do it, but I replaced the corroded line coming from Park Brake Valve Manifold to the "Tee" and the two hoses going to each drive. Fired the machine up, same problem at around 2000 rpm. Damn again. Went down to the john deere dealer purchased a 600 psi gauge, the fittings and a make-up hoses to do a pressure test from the manifold, (specs call for 250 - 300 psi to release brakes), I'm getting 370 psi. Now whats got me befuddled is why is it the right drive releasing after all this and the left brake drags? The line coming from the Park Brake Valve Manifold simply sends charged pressure to the "Tee" which splits it to the left and right brake. I would appreciate anybody's help or input.
So new final drive in the left side only? What happens to your brake pressure when you start to drive? Maybe its dropping off. As for one side dragging before the other: the brake disks are not going to be the same thickness, and the springs are not going to have exactly the same force. Check your brake pressure when your trying to drive, and post back.
Thanks for advise Gary. First off I did the pressure check from the park brake manifold to the brakes. I have the machine blocked up to turn both tracks. I meant to mention in the start of my thread that the machine will move forward and backwards before about 2000 rpm with no grinding noise from the left side. It is only when I increase the rpm, that the pressure drops, and I get grinding noise from the left side. Again after reading my thread did I realize that I left out this part of my diagnostics. One odd thing that keeps occurring while testing this way is that the gauge will drop to zero from 370 psi while in full throttle. When this happens, I reset the park brake switch and pressure will increase. At this time it has got me looking for some kind of electrical problem. I pulled the solenoid plug on the manifold to test for the click which I'm getting, but when I check for resistance across the terminals, I'm only getting 6.3 ohms but the book says it should read between 7 - 10.5 ohms. or solenoid has failed and to replace it. So that is where I'm at right now. The new solenoid will be in tomorrow and just takes a few mins to install. I am not sure if that will solve the problem, but at this point it seems to me to start isolating components that are working properly. I will post back when I get it installed and check that it is functioning.
OK, Good. The lesson here is, if you hear a grinding noise in one or more of your drive motors, suspect the park brake solenoid before you check anything else. $70 bucks and about 15 mins to change out. Now that is not to say just go ahead and buy one and put it on and expect the problem solved. You will need to test it first. If the resistance is below 7 ohms that means that it is too weak to operate a valve or something and causes you to loose charge pressure to your brakes, even if it is effecting only one drive. I believe as Gary stated above, that one disk may be thinner, or the spring may be weaker and that is what caused the right side to stay open and the left side to drag. There was barley enough pressure to keep the right side from dragging which caused me to come to the conclusion that I had a worn out drive. Oh well at least I have a backup drive now. Anyway, I'm as happy as a puppy with two peters now.