955H won’t move forward or backwards

I have recently acquired a Cat 955H I have changed all the fluids and filters oh yeah serial # 53A8065 anyway the good news is she runs well the bad I can’t get it to move forward or backwards. It has not moved since 2008. I checked the pressure on the oil line that runs from the trans hydraulic pump to the filter housing it was 100 psi. I also checked the 2 ports on the valve body the the steering pedals hook to 0 psi. I assume that the line I got 100 psi on is a return line the book indicates it needs 300 psi to function any help would be greatly appreciated my first machine so just learning.

Ah 53a makes it a 977h 1st question can you pull the gear selector in gear while its running

Delta211 said: I assume that the line I got 100 psi on is a return line the book indicates it needs 300 psi to function Click to expand... When you say “the book” do you have genuine Cat manuals for it or did what you have come from somewhere else.?

pittsburgh cat man said: Ah 53a makes it a 977h 1st question can you pull the gear selector in gear while its running Click to expand... Yes you can put it in any gear no restriction whatsoever and sorry 977h type O

Nige said: When you say “the book” do you have genuine Cat manuals for it or did what you have come from somewhere else.? Click to expand... I have the original cat manuals service and parts

Sorry my earlier post said 955H it is a 977H bad on my part .

Delta211 said: Yes you can put it in any gear no restriction whatsoever and sorry 977h type O Click to expand... Sure hope you have a good suggestion for me I am stumped right now.

There is a valve on top of transmission there should be two test ports my only 53a parts book is one down from your serial number range it shows the taps to be o ring boss try to get pressures from those two taps One more thing down by the side of seat there is a lever for range transmission might try moving that

i I have 0 psi at the 2 ports on the valve body that regular turning brake pedals are attached to?

This is the valve you are looking for it should be on top of the last picture

This is your transmission pump

Ok thanks should it have 300 psi there?

One tap about 300 other about 50 pound less