Hi folks at equipment forum re: 2004 430d with 4way I have finally decided to get unto the sticking load-sense resolver/shuttle that has been intermittently shutting off the loader circuit until I hold the backhoe valve closed and activate the loader circuit. I am having trouble identifying the resolver. Attached is a pic with numbers on bottom of the loader valve. Can anyone tell me which number is the resolver?
Aloha! Welcome to the HEF. I’m sure we can figure this out. I saw footage of those crazy green lights off the Kona coast this week. Watch yer six out there in the Pacific.
See the illustration below. It may not be 100% accurate for your machine but will be close enough. Each section of any control valve on your machine will have two resolvers in it. The first one comprises numbers 16 through 19. When you remove it make sure you do not lose the ball #19 because once you remove #16 there is nothing holding it in. Replace the seals/backup rings #17 & 18. The second one comprises numbers 20 through 23. Replace the seals/backup rings numbers 20 through 22. Take the shuttle valve #23 and shake it. Listen for the rattle of the captive ball inside it. If you can't hear a distinct rattle replace it. TBH you could do worse than replace the seals & backup rings on every section of the control valve. If you post a Serial Number then it may be possible to give more accurate information.
Hi Nige, Thanks for getting back to me The Ser# is BNK05975 The symptom I am experiencing is a occasional all function failure of the loader valve until temporarily relieved by holding in the hoe lift to stop while activating any function on the loader. I was under the impression that a single sticking load-sense resolver/shuttle caused this. What is your take? Mark
The steering is unaffected during the loader function failures
See the attachment. It is a parts listing for the lift section of the control valve valve from a 428D of the same generation as your 430D so should be comparable. All sections of the control valve pretty much use the same seals & backup rings. Your problem could well be a sticking ball in the resolver #17, referred to a "Housing As" in the parts list.
As there are so many resolvers is it possible to narrow down the culprit valve from the symptoms? In other words is one valve the most likely to cause flow failure to all the down stream valves and then be reset by deadheading the backhoe boom lift? I’m particularly curious about the primary resolver for the ‘smu’ Attached is the breakdown of the 430d with clam valve and flow charts
Now that pictorial representation is confusing! I never understood why Cat insists on calling shuttle valves resolvers. They don't resolve anything. They take one input and shuttle it between two outputs based on a condition. The title on the drawing says signal network, so does that mean there are pilot operated controls? The bottom arrow points to the right and says to pump control valve while the arrow above points in the same direction and indicates the flow is going to loader valve. Huh? Then it shows the loader valve with shuttles delivering oil to another shuttle valve to operate a function in series with the next function down the line. Finally it shows the last function being the left side outrigger and the last shuttle dumping oil back the reservoir. There is a lot of information missing. Do you have the actual schematic?
They are a resolver network they resolve the highest signal to the pump control the primary resolver is for both sides of the cylinder on that valve section The secondary resolves the highest pressure between valve sections actually the left outrigger is the first in the network because there is not a valve section in front of it it shows drain you will notice the bottom of primary resolver is connected to the valve section ahead of that section. And that by the way is how you check the resolvers you start a left outrigger hold leavers one at a time until the function you’re having trouble with starts working correctly the one you’re holding when it starts working is the one you need to check resolvers
So show me using that pictorial how someone is supposed to figure that out.
That chart is lifted from the System Operation document for the implement hydraulic system. Reading said document along with the embedded chart makes it understandable IMHO.
Attached said document for a C-Series BHL. The coloured version posted above is actually lifted from the service training guide. For the OP. This video on YouTube may help you understand the process better.
Ok folks; tell me if I am on the right track here. I have owned this machine for around 15 years and the fault has occurred twice, roughly five years apart. The problem has resolved itself for protracted periods after deadheading the backhoe boom valve in ‘boom up position’ and activating any function on the loader valve. Unless I want to replace every resolver upstream of the resolver for the priority valve that is attached to the loader valve, my hands are tied until I have another recurrence. When that happens, am I on the right testing track by deadheading the upstream valves in the following order: 1 right stabilizer 2 left stabilizer 3 backhoe stick 4 backhoe bucket 5 backhoe swing 6 backhoe boom while activating the loader lift valve and then replacing the primary and secondaries of the valve that resolves the issue possibly along with the resolver for the priority valve?
You will in all probability only have to install replacement backup rings & seals in the primary and secondary resolvers of the lift section of the control valve. That would be references 21-23 and 25-29 on the parts list of the 124-8818 control valve that you uploaded. The only exception would be if the ball in the primary resolver is jammed in which case the assembly #24 would need to be replaced. TBH the best thing you could do bearing in mind the age of the machine is go through all the resolvers and reseal every one. The cost of a complete set of seals will be very small.
Thanks everybody; I think I am getting the picture. The resolvers in the backhoe and stabilizer valves are irrelevant and the signal from any particular one of them won’t designate the culprit. On the 430d with 4-way the lift sect valve is 130-6520 and the clam valve is 124-8818 order from the front after the priority is ‘lift’, ‘tilt’, ‘clam’. The clam 124-8818 getting the juice last in line. So you think I should start with 188-7471 work backward from that and ignore the stabilizer and backhoe valves?