JD 550 dozer

[lorenzo]

Got this dozer and it would not move,the guy had messed with the control valve cause he was having reverse problems,i took the valve off and took it to john deere and they fixed it,well the forward gears work fine and the reverse does not,it will go in reverse but won't move until i throttle up,(wide open)but at idle speed it is only caring 30 psi and once it hits a 100 psi it starts to move,the max of pressure i can get out of it is 125 psi and that is the motor wide open,done the filter and the screen and put new fluids back in but still the same,how do i build the pressure up without takeing the pump out or is that the only way,or do you think i have a internal problem,looking for some info.Thanks

 

[mark ace]

MORE THAN LIKELY THE TRANSMISSION NEEDS TO COME OUT, DO A SEARCH, NO ONE HAS ANYTHING GOOD TO SAY ABOUT THEM? LOTS OF $$

 

[Anonymous-0]

I hope you got it dirt cheap...This is one of those that Deere shouldn't have made..I've done several rebuilds...Very expensive parts..No hard parts available aftermarket..Labor intensive..Last one I did , I found a donor machine and turned it into a 450-D...

 

[lorenzo]

Yea i know these type of dozer are a pain but i knew this dozer and the guy that had it,he spent a ton of money on it,(internal work)he was working this dozer and when he went and put it in reverse it would not back up the hill,he was in a pinch and needed to sale so i bought it,just needing some info,it is just going to be a farm dozer now,Thanks.

 

[720 in pa]

it sounds like the reverse clutch pack is leaking pressure,which means the transmission has to come apart to fix.what kind of pressure do you have in forward?i think system pressure on those is around 160-180

 

[lorenzo]

I have the same pressure in the forward gears as i do the reverse gears which at low idle is 30 psi,but it will go forward but not reverse at low idle.

 

[720 in pa]

sorry i told you wrong on pressure.it should be 250-280 psi

 

[720 in pa]

also if you have service manual on it,it will show you where to check the reverse pressure.check that to see if it is same as system pressure.you should have much more than 30 psi