I have a circa 1980 fiatallis 10C dozer that will stop working in first hear forward and reverse after about 20-30 minutes. 2nd and 3rd will work fine. It seems that when the transmission fluid warms up it is possible leaking past a seal or something and will no longer have enough pressure to engage 1st gear. The transmission oil pressure guage is the only one that works and it starts out barely in the green and as i work the machine it will drop into the red before it finally stops engaging 1st gear. I am very new to this so I do not know where to look. Filters have been cleaned and both main hydraulic filters cleaned/replaced. Is there a replaceable seal external to the actual Trans that I can access to check? Any help is appreciated.
Their is nothing external sounds like the first gear clutch pack is either getting weak or the seals on the apply piston are bypassing.
You are checking trans. oil with engine running. You might want to check the pump since it sounds like your low on pressure from the get go, only thing is if you've slipped that clutch pack a few times it sounds like and it most likely isn't long for this world even with a replaced pump.
This may be dumb but is there a separate transmission pump? I replaced the main hydraulic pump that is connected right by the engine due to a Crack in the housing.
I wouldn't think the implement pump has anything to do with the transmission but maybe someone familiar with Fiat Allis machines will see this thread.
No separate pumps I would have to look and see if I have anything left on the 10c dozers or loaders as they are basically the same.
Is yours a direct drive or torque converter model? The hydraulic pump set up on direct drive and torque converter models are different. I have a 1980 year of manufacture direct drive model, and have also replaced the equipment pump (No 1 below) because of a cracked housing. For direct drive model, there are 3 independent hydraulic pumps, as below, all located at the rear of the master clutch housing. 1. The big pump directly under your left foot as you sit in the operator's seat is the equipment pump, servicing the blade and ripper hydraulics. It is the largest of the three. 2. The pump directly under your right foot as you sit in the operator's seat is a twin section pump, both sections contained in one pump housing. The "front" section (closest to the front of the machine) is for the transmission charging pump, and the "rear" section is a scavenging pump, which picks up oil from the bottom of the master clutch housing and puts it into the transmission sump. 3. The pump sitting more or less between the above two, but also more or less under the equipment pump and thus also indirectly under your left foot is the steering brake and clutch pump.. If yours is the torque converter model, attached is schematic of 10C torque converter model hydraulics. (10-C T.C. Model Trans & Torque Converter Hyd Control System)