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cat hydraulics

nick.o

Member
Joined
Jul 12, 2017
Messages
22
Location
Charlotte, North Carolina
Ok, so having a similar problem with hydraulics after replacing resolver valves. I have been using machine without any problems until yesterday. i was moving some stumps with the clam and lifting them up to move. one was fairly heavy, and it moved it fine, but shortly after that all loader, clam, lift and curl barely work at all. The hoe works fine except the swing seems slow and stabilizers. Any help would be appreciated. 89 cat 416 serial # 5pc08594
 

kshansen

Senior Member
Joined
Mar 11, 2012
Messages
11,157
Location
Central New York, USA
Occupation
Retired Mechanic in Stone Quarry
Ok, so having a similar problem with hydraulics after replacing resolver valves. I have been using machine without any problems until yesterday. i was moving some stumps with the clam and lifting them up to move. one was fairly heavy, and it moved it fine, but shortly after that all loader, clam, lift and curl barely work at all. The hoe works fine except the swing seems slow and stabilizers. Any help would be appreciated. 89 cat 416 serial # 5pc08594
Right off I have zero experience with Cat Back-hoes!
But if you send me an email address by using the "Start a conversation" option on this site I could send you a
"Implement Hydraulic System Testing And Adjusting" for your machine.
 

nick.o

Member
Joined
Jul 12, 2017
Messages
22
Location
Charlotte, North Carolina
I was on the machine and while using front loader I operated the backhoe at the same time and the front end loader would work. Does anyone have any idea what causes that to happen.
 

nick.o

Member
Joined
Jul 12, 2017
Messages
22
Location
Charlotte, North Carolina
I'm going to work on the hoe valve today to make sure no debris blocking resolver. I checked all the front end loader resolvers already, it made zero difference. Thanks for responding, I will update when finished.
 

nick.o

Member
Joined
Jul 12, 2017
Messages
22
Location
Charlotte, North Carolina
Just got through checking and cleaning all primary and secondary resolver valves , no change. Front bucket raise and tilt move a couple inches then stops. Release and actuate again and goes up a couple inches unless actuating hoe at the same time, then front works normally. Stabilizer also works slow but works.
 

Cmark

Senior Member
Joined
Jan 2, 2009
Messages
3,178
Location
Australia
Operate each section of your backhoe valve in turn whilst operating the non-functioning loader. The first section you come to that makes the loader work properly is the section with a faulty resolver.
 

partsandservice

Senior Member
Joined
Feb 14, 2011
Messages
846
Location
Georgia
I seem to recall there is another resolver or load sense check valve on the back of each section. The small socket head plug is where it is located. The check ball on this one is not contained in the resolver and can get loose .KIMG0063.JPG

This is a picture of the of the resolver under the spool cap.KIMG0062.JPG
 

partsandservice

Senior Member
Joined
Feb 14, 2011
Messages
846
Location
Georgia
Sorry about the redundancy, I just saw where you stated had checked all the resolvers. However you still have a load sense issue. There is a flushing procedure to clear debris . Maybe Cmark could give a description of this procedure with his access to et .
 

partsandservice

Senior Member
Joined
Feb 14, 2011
Messages
846
Location
Georgia
There is also a resolver in the inlet section of the loader control valve which is the steering priority valve. The flush procedure is to remove the check ball from the secondary resolver (s) and replace without the check ball then operate the controls , this will flush any debris back to tank that could keep the check ball from seating.
 

nick.o

Member
Joined
Jul 12, 2017
Messages
22
Location
Charlotte, North Carolina
Ok, finally repaired the problem. All resolvers were changed. I rebuilt the the hoe valves. Found a problem with one of the pressure relief valves. One of the springs in the valve was broken on both ends, and the piston was stuck due to abnormal wear. The broken ends of the spring were not in the valve. Replaced the pressure relief valve when rebuilding the unit. This still didn't resolve the problem. I removed the spooler valve on the pump and disassembled it and cleaned it out, put back on the machine and the machine works great. I think there must of been some filings in the valve and prevented the piston shafts from moving and telling the pump to operate. I want to thank everyone for helping me in this matter.
 
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