Hi, broken 1961.
It is my understanding that the filter is placed in line before the oil returns to the reservoir where the pump could pick it up - along with any contaminants that might be in it - and pump it through the system again. This would mean that it would have to be about the last thing on the pressure side - which is basically what Old Magnet is saying.

Just my 0.02.

Should have posted this at first but was pressed for time...

Thx Guys, the oil flow schematics really helped me understand whats going on with it, was trying to understand how water could get into the transmission oil, but if its on the suction side , it makes sense now, thx again, Scott

"broken1961" wrote:

Thx Guys, the oil flow schematics really helped me understand whats going on with it, was trying to understand how water could get into the transmission oil, but if its on the suction side , it makes sense now, thx again, Scott

Point is, the cooler is not on the suction side, it's on a low pressure return circuit from the torque converter outlet relief valve back to the reservoir.

Only thing to do is pressure test the cooler, 'cause at some point, either while machine is running or stopped, the coolant will have greater pressure than the oil in any cooler.

Got bitten by the old adage that a leaky oil cooler puts oil in coolant not coolant in oil. Had an oil pan full of coolant after the tractor was parked for a while............turns out replacing the oil cooler for less than $100 fixed the problem after the engine inframe overhaul $$$ didn't! So it pays to diagnose the problem to confirm before starting on a big repair.

It is common to get milky trans oil on these machines from prior contamination and condensation from setting for long periods. Just out of curiosity did you actually check pump pressure i think min is 265lbs to release clutches normal pressure is 315-365 lbs also check suction lines and magnetic strainer gaskets and orings. If your pump is not pumping it will still push but wont steer i had an old fence post get between my belly pan and cross beam and tag my suction line. Could not see it until i removed pan and dozer did exact same thing

Hi broken1961, I'm sorry I didn't post this sooner.

Craig

It has been a while , but we have it apart, the oil we drained out was grey and thick, we drained it in 4 places. We pulled the magnetic strainer, it was collapsed in the housing, also pulled the cooler, pressurized it, and didn t see any leaks, but who ever was in there before had stripped the bolt holes, and just locktighted them in, so planning to install a new cooler. The way the screens were collapsed, I think it was starving for oil, hopefully its a cheap fix for it, thx Scott

Hi Team,
from memory have also have found water ingress via broken Steer clutch cover breathers--if fitted-- under the fuel tank, loose steer compartment cover plates and or missing bolts from same as well as Steer brake adjuster covers, ditto the Bevel Gear centre top access cover under the steer valve, cracked cases where the chassis side arms attach to the main rear case along with rusted thru trans. pump suction lines, loose hose clamps on those not modified to swagged end style hose suction lines used on later units --if working with snow drift in belly pans it can melt around the warm Trans suction lines--working in water, condensation from short runs in cold weather building up in the steer compartments etc.--- all I can think of at this time will add if needed.

Cheers,
Eddie B.

Still fighting with this d7, changed transmission pump, put a gauge on before, old pump was at 250, new pump is at 350psi, but still doing the same thing Transmission acts like it isn t getting oil pressure, would there be a relief valve hung open?