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Weird Hydraulic Issue cat 315CL
- Thread starter floridamechanic
- Start date
-
- Tags
- hydraulic help
Kobelco ireland
Senior Member
I am out in service van and won't be back in workshop till Saturday so have no access to books till then. What model and year machine are we talking about I am not trying to prove you wrong on this I am just interested for my own knowledge cos its something I have not come across
Kobelco ireland
Senior Member
?…………………..and this is why you shouldn't throw someone under the bus before all the facts are in.
Kobelco ireland
Senior Member
uffex
Senior Member
Good day guys
I have read this thread several times so I hope I did not mess up, I have made notes and drawn the following conclusion from what has been posted.
The pump howl was the original issue and I suspect this has not been resolved, the illustrating video if I have followed correctly does not indicate a significant problem.
I have posted my notes without so that you may see where my conclusion has come from.
First post
Pump howls when the ram is powered outwards away from the machine.
Post Jan 17
Tank pressure is 2 lbs this will only max out when you fully stroke the cylinders a couple of times.
Post Jan 18
Nige Suction strainer condition important
Funwithfuel check if you have a pump issue flow testagain a very important question
John C comment very low hours Indeed very low for a pump failure
Report that both pumps are making 4900 p.s.i (345 bars) enough to work the machine.
Question when did this howl develop?
Are you aware that the cylinder force for arm out is considerably less than that for arm in.?
Jan 19
Funwithfuel is focused on pump flowyou do not appear to have made the crawler speed check he requested, you have only stated that the dealer had given a green light but the dealer did not fix it.
I suggest you check it and confirm if it meets specifications.
In the video you appear to be operating the arm out in unison with the boom down and raising the undercarriage, when you do this you are not only using the boom cylinders negative chamber which may I point out is the weak side of the cylinders,lifting power will increase when you operate the arm as you have added an additional cylinder to support the weak side of the boom cylinders. If i have followed your actions correctly this is a normal reaction from most excavators.
Pilot pressure is that 900 p.s.i. 63bars that seems high to me 595 I believe is normal. Adjust to the correct level on Jan 20.
Feb 1
Case drain filter burstindicates excessive case drain flow
TVAgood advice check out the pumps first.
Comments that the pumps make high pressure conflicts with excessive case drain
Pumps failing at the hours on the machine would be considered as apremature failure has the hydraulic fluid been tested for visco what is the condition of the suction screen filter?
Feb 2
TVAcomment back to the suction system !!correct what has caused the pump to fail if it has ???
Take the pump apart good advice
Feb 5
Cmark take the pump apart good advice try to establish root cause.
Nige check the fluidgood advice seems to go unheeded
I have read this thread several times so I hope I did not mess up, I have made notes and drawn the following conclusion from what has been posted.
The pump howl was the original issue and I suspect this has not been resolved, the illustrating video if I have followed correctly does not indicate a significant problem.
I have posted my notes without so that you may see where my conclusion has come from.
First post
Pump howls when the ram is powered outwards away from the machine.
Post Jan 17
Tank pressure is 2 lbs this will only max out when you fully stroke the cylinders a couple of times.
Post Jan 18
Nige Suction strainer condition important
Funwithfuel check if you have a pump issue flow testagain a very important question
John C comment very low hours Indeed very low for a pump failure
Report that both pumps are making 4900 p.s.i (345 bars) enough to work the machine.
Question when did this howl develop?
Are you aware that the cylinder force for arm out is considerably less than that for arm in.?
Jan 19
Funwithfuel is focused on pump flowyou do not appear to have made the crawler speed check he requested, you have only stated that the dealer had given a green light but the dealer did not fix it.
I suggest you check it and confirm if it meets specifications.
In the video you appear to be operating the arm out in unison with the boom down and raising the undercarriage, when you do this you are not only using the boom cylinders negative chamber which may I point out is the weak side of the cylinders,lifting power will increase when you operate the arm as you have added an additional cylinder to support the weak side of the boom cylinders. If i have followed your actions correctly this is a normal reaction from most excavators.
Pilot pressure is that 900 p.s.i. 63bars that seems high to me 595 I believe is normal. Adjust to the correct level on Jan 20.
Feb 1
Case drain filter burstindicates excessive case drain flow
TVAgood advice check out the pumps first.
Comments that the pumps make high pressure conflicts with excessive case drain
Pumps failing at the hours on the machine would be considered as apremature failure has the hydraulic fluid been tested for visco what is the condition of the suction screen filter?
Feb 2
TVAcomment back to the suction system !!correct what has caused the pump to fail if it has ???
Take the pump apart good advice
Feb 5
Cmark take the pump apart good advice try to establish root cause.
Nige check the fluidgood advice seems to go unheeded
floridamechanic
Well-Known Member
Could not stand it went to big city got fittings, test results all at full throttle
call pump closest to counterweight pump #1
Call pump closest to bucket pump #2
Started unit and at full throttle pump #2 had 2k lbs, hit boom up an pressure drop to 1000lbs at boom up max, no pump noise
and pump #1 had 900lbs, as boom went up it dropped ending at zero with full boom up,
So i shut it off and recorded results, restarted now pump @2 has right at 1000lbs and drops to 500lbs at full up, push boom down at half throttle unit goes up in air like old times,but when I do stick in/out or boom up/down i get slight slipper shoes sound just for split second, and real light, but pump #2 will not drop to zero like pump one, curl bucket in or out at stops gauge is zero and lugs motor, now will lug motor boom up/down--stick in/out, so do I have trash in valve or valve sticking? hooking gauges up at valve block not at pumps, have to go get on dozer before lose this job be back this evening
call pump closest to counterweight pump #1
Call pump closest to bucket pump #2
Started unit and at full throttle pump #2 had 2k lbs, hit boom up an pressure drop to 1000lbs at boom up max, no pump noise
and pump #1 had 900lbs, as boom went up it dropped ending at zero with full boom up,
So i shut it off and recorded results, restarted now pump @2 has right at 1000lbs and drops to 500lbs at full up, push boom down at half throttle unit goes up in air like old times,but when I do stick in/out or boom up/down i get slight slipper shoes sound just for split second, and real light, but pump #2 will not drop to zero like pump one, curl bucket in or out at stops gauge is zero and lugs motor, now will lug motor boom up/down--stick in/out, so do I have trash in valve or valve sticking? hooking gauges up at valve block not at pumps, have to go get on dozer before lose this job be back this evening
When you come back, start the machine, let it warm up, put it in normal digging mode ( if it works) or high idle ( let’s say half of available RPMs or a little lower if your modes don’t work ) and run tests again. Don’t do combined operations, at this point dead heading something is not that important as have joystick all the way in full position. I don’t know your pattern, but let’s say yor right joystick operates boom and bucket, operate the longest cycling one and watch the pumps NC pressures, one of them should drop pressure considerably - read and record that one! Then switch to the other.
floridamechanic
Well-Known Member
both normal digging and high idle, just did that and came in and read your request, unit warmed up both nc show 900lbs, all functions are a LOT stronger since putting test fittings on, for some reason,
boom full up both go to zero try kill engine
boom down #2 pump drops from 900 to 450 an stays at that no lower, pump #1 stays at 900
stick out both pumps drop to zero and load motor hard
stick in both drop to zero and load engine hard
curl in and out both drop to zero and load engine hard
getting chirp chirp thru all functions
boom down 10 times stronger than when first started and pump #2 was at 2k at high idle in neutral then all sudden has fallen to 900 and a lot more power but still not dropping to zero in boom down
oh yea I still have old pump lol
boom full up both go to zero try kill engine
boom down #2 pump drops from 900 to 450 an stays at that no lower, pump #1 stays at 900
stick out both pumps drop to zero and load motor hard
stick in both drop to zero and load engine hard
curl in and out both drop to zero and load engine hard
getting chirp chirp thru all functions
boom down 10 times stronger than when first started and pump #2 was at 2k at high idle in neutral then all sudden has fallen to 900 and a lot more power but still not dropping to zero in boom down
oh yea I still have old pump lol
Let’s wait for the rest of the council to chime in! But I agree with John and I think what you just said hints more that way - that you having NC drain and unloaders sticking issues!
Do you think you can find those orifices by Johns directions?
I take your 2000psi was on cold oil? Another question are al the return lines from control valve to tank clear.
Again feels like drainage issue.
Do you think you can find those orifices by Johns directions?
I take your 2000psi was on cold oil? Another question are al the return lines from control valve to tank clear.
Again feels like drainage issue.
floridamechanic
Well-Known Member
TVA I ain't got a return line clue? lol, yes can/will follow directions if ya'all can do' 'run spot run'' directions, by now ya'all know I ain't the sharpest knife in the drawer-- yes was on cold oil
jonno634
Well-Known Member
if some are thinking it is a case drain (or return line back pressure issue), it could be a failed hydraulic line on the inside of the hose, making a restriction. (I am new to excavators, but have worked on farm machinery with hydraulics for a long time, and have had failed hoses on the insides more than once.). Just an outside the box thing I thought i’d offer....
floridamechanic
Well-Known Member
correct boom an bucket curl right stick ==10wt yes it drops from 900 to 450 on #2 pump I think if would drop lower then other pump would kick in but not sure, was crazy b/c went from 2k in neutral to 900 in neutral in a 60 second shutdown/restart, and has remained there
John C.
Senior Member
Now we are getting some results that can be interpreted. Part of what is happening is that you have combined flows from both pumps depending on situations. Run the test again this time using only the tracks. Pick up one track and slowly start it spinning. The associated gauge should slowly drop as you add speed. When it is full speed the gauge for that pump should read zero or near it. Then do the same test on the other track.
floridamechanic
Well-Known Member
thanks jonno we are taking all offers lol ok will be back few minutes