i just bought a 1882 build 245 cat excavator on delivery they broke the head on the stick cylinder so rebuilt that replaces some hoses and such now it has decided to swing to the left constantly it will go around and around picking up speed to the point where it wants to flip the machine . i pulled the pilot vale on the left control which is dead sticking right now and no issues some minor wear gunk but nothing special one would thing they would put a magnet sink in there to catch the wear crap .anyways pulled the pilot vale apart no issues flushed it cleaned it and still same this machine swings to the left constantly any ideas as to where i should start looking for next possibility? serial number is 84x663 .made in belgium in 1982 the salesman said it was a 86 so have no clue there . but any advice would be appreciated as anytime i touch the thing it costs thousands @Cat up here it is 166 a hour and a 500 call out 3k to take it to them so am am trying to fix it myself but got lost in the maze of hoses trying to trace where they go there's 4 small ones on the side of the valve and two to feed and return and there is one small one on the bottom under the feed tubes .
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245 nightmare
- Thread starter 254lemon
- Start date
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- Tags
- swing issue
BigWrench55
Senior Member
I would tee into the pilot line at the main control valve with a gauge. And see if you are getting pilot pressure at the function in question. Or disconnect the pilot line and plug the line and cap the valve. If you use the gauge and you don't have any pilot pressure at the main control valve. But the machine still swings. Or if you disconnect the pilot line from the main control valve and it still swings. Then the spool is stuck. If you have pressure when you are not activating the control. Or if it doesn't swing after disconnecting the pilot line. Then you have a pilot control valve problem.
John C.
Senior Member
I'm hoping for you sake that the 1882 isn't the model year of the machine.
About all I can give you is my deepest sympathies. That's a whole lot of old iron to feed and care for.
About all I can give you is my deepest sympathies. That's a whole lot of old iron to feed and care for.
Dave Neubert
Senior Member
Does it swing with the safety lever in the off position
yes it does
no 1982 is the build my fat fingers
yes i t does i have to up the revs to start it with the bucket on the ground
Considering it will do it with the safety in the down position I'm tend to think the spool is stuck in the main control valve. Other wise you'd have 2 problems 1 being that pilot pressure is supplied when the lever is down and 2 being to left swinging. Don't let it swing left too much it will unscrew.
Dave Neubert
Senior Member
Spool in main valve is stuck pull the piolet servos off the top and bottom of the swing valve pull spool out and clean it or the return spring may be broken. Maybe you got some trash in the valve when the head broke
after being ignored by cat themselves i want to thank all of you for the responses the main bock is where i am heading just waiting for a service manual i ordered to show up so i can have some semblance of which bank is the swing on my main control block .i think i know which ones to pull but want to be sure .
i am inclined to think that when i involuntarily changed the fluid as when i rebuilt the stick cylinder as head cracked during shipping driver learned a lesson chain the rod if in down position as older machines weep and the rod extended and slapped around in -40 celcius weather on the way here .and then blowing a main pump feed line so flushed the system 2x in a month . it happens new to me machine and all , but i am thinking maybe sludge from bottom of tank maybe could be bugs they love to infiltrate systems never could figure out how they get in but they do .was strange though was all working fine then it just decided to try helicoptering to the left removed and cleaned the pilot valve no issues there so has to be in main block like you all said . again thanks for all the advice am pretty handy with mechanical but has been a long time since i had to diagnose hydraulics in a beast like this one .
ok so spool was stuck some dummy must have had it apart before me as it looks like it was dropped and had a burr on one edge of the spool filed that down does not free swing anymore but left swing is unresponsive and when i try it it jolts the other stick and the foot pedals like a surge kind of like thought maybe i hade the spool in the pilot valve backwards spun it and same thing everything else now works though so am gonna do some more digging have no way of testing other than trying to disconnect the hose at the main and see if i get any fluid .am winging it here guys no manual yet so am fishing in the dark .
would it not show up in the fluid drained by pulling the spool? i have filtered the fluid i drained and found nothing in the spool area am going to reverse the hoses and see if i can get the left circuit working as the right swing works fine if that works then it must be somewhere in the left swing circuit
Not necessarily. If you are lucky yes but with the flow of oil it can push a piece of debris into the return circuit of the system. Most of the time it will end up in the return filter inside the hydraulic tank, or trapped in a hose or fitting in the return circuit.
If you switch the main lines on the swing motor and your problem "moves" to the right side, then your issue will be in that main control circuit of the swing section. If the problem stays the same I would be looking at the swing motor itself.
so pilot valve works fine swapped hoses and the issue is still there but control was switched i guess i have to dig deeper gonna drain fluid and swap drive hoses se what happens there if it will swing left again i am gonna assume the main valve body