I have a mid 80's case 850 d peddle steer dozer with around 5k hrs. I have been having trouble with the steering for a while. The left peddle will go to the floor and I have to pump it to get it to steer. Now if I'm running the machine for very long at all it will almost come to a stop. If I hit the right steering peddle it seems like it free's up and takes off a little. I can hear a sound like a rub or something holding when it does this. Any help to diagnose this would be greatly appreciated.
Welcome Chase27! Firstly, Case transmissions are designed to be driven on the levers. Brakes are to be used for tight turns & stopping. The design of the brakes does not allow for 'steering' as the linkages / cotter pins etc will simply wear out. In saying that, it doesn't help you with your problem right now but will save you grief in the future. Is there oil in the brake master cylinder? You are using mineral oil & not dot 3 brake fluid? Next, you need to see what the brake slave cylinders are doing while you are moving the pedals. If the slave is moving, try to adjust the brake & see if that helps, that should stop the need to pump the pedal, if the adjustment is low. Does the transmission neutralize when the brake is applied?
It has dot 3 brake fluid in it. What kind of damage does that do? The transmission doesn't act like its slipping or neutralizing, it acts like its straining to go.
By using the dot 3 fluid, all the rubber seals will swell. The slave cylinder may be seizing up & dragging the brakes. The pedal is probably feeling weird, cause the slave return spring is not pushing the oil back into the master cyl. Check & see how much movement there is at the slave cylinders, while pushing the pedals - compare LH & RH. There are LH & RH neutralizing cylinders/valves on the front of the transmission control valve, these are activated by the brake master cylinders - these may be binding as well. You may need to reseal both the master cyls / neutralizers & slaves before you can do much else. The dot 3 is heavier than mineral oil & seems to go to the lowest point of the system - you will at least have to pull the slaves & reseal them. Flush the master cyls & lines with clean oil while the slaves are out - then see what happens from there.