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I have a cat 428c series 8rn single tilt on the bucket.The…

I have a cat 428c...
I have a cat 428c series 8rn single tilt on the bucket.The back hoe is functioning normal but front bucket will not lift or tilted.If you touch the liver on the dipper arm the bucket will lift and function normal.Kind regards Terry.
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Answered in 3 hours by:
8/13/2014
Mechanic: catmastertech, Technician replied 8 years ago
catmastertech
catmastertech, Technician
Category: Construction and Road Equipment
Satisfied Customers: 3,966
Experience: Field service technician for CAT 19 years.
Verified

Hello, thank you for your question.

This is a common complaint when the resolver seals have failed in the valve.

You should replace the seals on all the resolvers as most likely, they are all in poor condition. The reason they fail is the constant exposure to hot oil. This is a normal problem and nothing else should be wrong with your machine.

If the resolvers appear rusty or damaged, you may want to purchase new seats and assemblies as the old one could be difficult to remove. If you are concerned about working with the valves, you may want to remove the loader valve assembly and have it resealed by your dealer's hydraulic shop.

This is not a hard job except for removing the float latch on the lift valve and the detent for the "Return-to-Dig" solenoid on the tilt valve.

Your resolver seats can be removed with an "Allen" wrench. You have access holes on the right side frame to remove the secondary seats. The primary must be removed from the bottom after removing the bottom cap.

Below is an image of the valve's resolvers.

1 - primary

2 - secondary

If you need more help, please let me know.

Thanks, Donnie

catmastertech
catmastertech, Technician
Category: Construction and Road Equipment
Satisfied Customers: 3,966
Experience: Field service technician for CAT 19 years.
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Customer reply replied 8 years ago
Thank you very much for the information about the cat 428c.I have ordered the seales and am expecting them in two weeks time,we are based in West Africa,The Gambia.If I need any information I will be in touch..Thank you very very much..Regards Terry
Mechanic: catmastertech, Technician replied 8 years ago

You are welcome. If you do need help, please let me know. I will be glad to help all I can.

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Customer reply replied 7 years ago
Hi we have done all you advised us to do but the machine is having the same problem. The bucket will not tilt and is not going up and down but when you touch the steering everything will function normal. We have change all the seals in the valve block
Regards Terry.
Mechanic: catmastertech, Technician replied 7 years ago

Did you change the seals in the inlet section of the loader valve?

Did you remove and clean the steering priority valve in the inlet section?

How does the rest of the backhoe functions work?

Can you stall a backhoe function and see the power return to the loader controls?

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Customer reply replied 7 years ago
Hi thanks for reply
We have change all the seals in the inlet section
We have removed and clean
The back hoe function is working perfect
No we can not stall the backhoe function .
8rn05266 this is the serial no. Of the machine
Thanks Terry .
Mechanic: catmastertech, Technician replied 7 years ago
Hello, at this point I need to know the pressures you are seeing for all the controls.
Please post the pressures for all the hydraulic functions and steering. Please include margin, standby and high pressure cutout for the pump. Monitor signal pressure and pump pressure when operating the loader function. Note the pressures on both gauges to see the differences of the signal and pump pressure.
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Customer reply replied 7 years ago
The pressure on the front bucket and the back actor is 1200 psi and now the front bucket and steering is not working but the back actor is working very slow, is not functioning normal.
1200psi is a pressure directly from the mainly hydraulic pump.
Thanks Terry
Mechanic: catmastertech, Technician replied 7 years ago

Sorry for the late reply, this question was missing from my list. I had to track it down to find your posting.

Is it possible you have trash in the hydraulic system?

This appears to be a signal leak from a resolver. Did a resolver ball get left out?

Have you check the filter for debris in the hydraulic oil?

Did the machine has a recent failure? Any signs of other repairs like new hoses or repaired cylinders?

Here are details about the resolvers.

There are two resolvers per implement control valve. Primary resolver compares the rod end hydraulic pressure to the hydraulic pressure for the head end of the cylinder. Secondary resolver compares the highest primary signal in the control valve to the highest primary signal in the next control valve. The secondary resolvers are arranged in series and the secondary resolvers lead to the pump compensator valve.

A resolver is a shuttle valve that is a double ball check valve. The resolver compares the two pressures. The highest pressure moves the ball. The ball blocks the lower pressure. This higher signal pressure flows to the next resolver in the resolver network.

The primary resolvers and the secondary resolvers can be affected by the following items.

  • debris

     

  • cut seal

     

  • missing seal

     

  • bad ball resolver seat

     

  • missing resolver ball

The signal network can be easily checked. Install one 6V-4143 Coupler Assembly to each end of the 6V-3014 Hose Assembly. Install the 8T-0860 Gauge with a range of 0 to 40000 kPa (0 to 5800 psi). Install 6V-3014 Hose Assembly to signal pressure tap.

Start the engine and warm up the hydraulic oil to the operating temperature. Run the engine at LOW IDLE. Operate each control lever in the following order for the 416C, 426C or 436C machines:

     

  1. Auxiliary (if equipped)

 

     

  1. Boom

 

     

  1. Swing

 

     

  1. Right side stabilizer

 

     

  1. Left side stabilizer

 

     

  1. Backhoe bucket

 

     

  1. Stick

 

     

  1. Extendable stick (if equipped)

 

     

  1. Auxiliary for the loader (if equipped)

 

     

  1. Loader bucket tilt

 

     

  1. Lift control for the loader

 

     

  1. Priority valve

Operate each control lever in the following order for the 428C or the 438C machines:

     

  1. Boom

 

     

  1. Swing

 

     

  1. Left side stabilizer

 

     

  1. Right side stabilizer

 

     

  1. Backhoe bucket

 

     

  1. Stick

 

     

  1. Extendable stick (if equipped)

 

     

  1. Auxiliary for the loader (if equipped)

 

     

  1. Loader bucket tilt

 

     

  1. Lift control for the loader

 

     

  1. Priority valve

Operate each of the implements against a load. Watch the gauge. The maximum system pressure of 20700 ± 700 kPa (3000 ± 100 psi) should be reached for most of the circuits. The exceptions are the boom LOWER, the steering circuit and the loader DUMP for parallel lift machines. By using the gauge, small leakage problems such as a cut seal or a missing seal can be detected.

Secondary Resolvers with Two or More Valve Sections

If two or more of the control valves in series fail to work properly, the problem may be in the secondary resolver of an upstream implement control valve. The first control valve receives the pump supply oil first. If the secondary resolver for the control valve does not work properly, the secondary resolver may allow signal pressure from any control valve that is further from the pump supply to leak back to the tank.

This leakage may be caused by a resolver ball that is not seating or by a resolver ball that is blocking the signal oil to the drain. Signal oil from a downstream control valve may be at a higher pressure than a control valve that is closer to the pump. However, the faulty resolver will not allow the downstream valve to function properly.

A leakage in the resolver may be caused by a missing resolver ball, debris that prevents the resolver ball from properly seating, a missing seal or a leaking seal. When multiple control valves malfunction, first operate the malfunctioning valve that is farthest from the pump. Operate the other control valves, while you operate the control valve that is farthest from the pump. Operate the other control valves one at a time until a control valve operates both implements.

This is the control valve with the bad secondary resolver. The farthest control valve is sending a signal and the control valve with the faulty secondary resolver is also sending a signal. Because the control valve with the bad secondary resolver has a leak, the signal from the farthest control valve cannot flow to the pump controller until the control valve with the faulty resolver is operated.

Primary Resolver Versus Secondary Resolver

For control valves with a flow control spool, if one control valve section fails to work in one or both directions, the primary resolver or the secondary resolver in that control valve may be faulty. For control valves with a flow control spool, if one of the control valves works slowly in one or both directions, the primary resolver or the secondary resolver in that control valve may be faulty. In order to determine the faulty resolver, perform the following check.

Stall an implement control valve downstream from the malfunctioning valve. This will force the malfunctioning valve's secondary resolver ball to move away from the seat on the drain end.

This eliminates the possibility of a leak on the drain end of this secondary resolver. While you stall the downstream control valve, operate the malfunctioning control valve. If the control valve is still operating slowly in one or both directions, then the primary resolver may be faulty.

When the primary resolver is faulty, the faulty resolver bleeds off the pressure, which affects the operation of the flow control spool. The combined force of the signal oil pressure and the flow control spring is not enough to move the spool. This prevents additional oil to flow to the cylinder. The load on the cylinder is greater than the amount of oil that is flowing to the cylinder, which causes the implement to have a slower response.

Normally if an implement is slow in both directions, the problem is usually in the secondary resolver. If an implement is slow in only one direction, the cause is typically caused by a faulty primary resolver.

The causes for a faulty primary resolver are the same causes for a secondary resolver. A leakage in the resolver may be caused by a missing resolver ball, debris that prevents the resolver ball from properly seating, a missing seal or a leaking seal.

Other causes of a malfunctioning valve section might be a misadjusted linkage, a broken pressure reducing valve spring, a flow control spool that is incorrectly installed, a faulty line relief valve or a faulty makeup valve.

Note: As a recommendation, flush the system if there is debris in the system. Flush the system by removing all of the resolver balls in the secondary resolvers. Then operate the implements. There will be enough oil flow in order to flush the debris to the tank.

Follow this test and let me know the results. Hopefully this will point you to the faulty resolver.

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Customer reply replied 7 years ago
Hi we have found out that the valve block is worn out which is mixing oil on the lift up and. Do you have one for sale or know somebody who might have one.
Thanks for all your help you been given to us
Best regards. Terry
Mechanic: catmastertech, Technician replied 7 years ago

I am sorry for the late reply. I tried to send a post to you this morning but, had internet problems.

That is a new issue for me, I guess this machine has seen lots of use.

I don't know of any way to get these from the manufacturer. The only way to be certain you will have the correct part is to use CAT parts.

When I am working on an older machine and the customer is looking to save some money, I ask for the dealer's used parts people to see if they can find me what I need.

They may source a whole loader valve assembly for the price of this one section. I don't know if they are willing to separate a group but, it is worth asking. Most dealers will sell used parts at or below half of new part prices.

At least a used part is the correct part, I don't have to worry about flow or pressures being wrong.

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Customer reply replied 7 years ago
Hi I have a cat D6 C 47J series and am I have problem with the Torque divider Group 5M 5800
I want to know all parts and their numbers on the Transmission shaft and if you can send a diagram of the transmission shaft which show all the parts on it I will be grateful.
Thanks Terry.
Mechanic: catmastertech, Technician replied 7 years ago

Hello, I will be glad to help you with this.

Please start a new question and include the machine, transmission and torque divider/convertor serial numbers. These machines have been rebuilt for so long some changes may be present that are not identified under just the serial number prefix.

Thank you, Donnie

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Customer reply replied 7 years ago
Thanks for that the machine serial number is. 47j04701-upThe torque divider group is. 5M5800Torque converter is. 1T930This are the numbers I found hope it will be of grate help.Thanks Terry.
Mechanic: catmastertech, Technician replied 7 years ago
Thanks for the serial numbers. Please open a new question so I can reply.
catmastertech
catmastertech, Technician
Category: Construction and Road Equipment
Satisfied Customers: 3,966
Experience: Field service technician for CAT 19 years.
Verified
catmastertech and 87 other Construction and Road Equipment Specialists are ready to help you
Ask your own question now
Customer reply replied 7 years ago
The part number for the torque divider group is 1T930For the machine serial number is.47J04701-UP
The torque divider group is. 5M 5800 Torque converter 1T 930
Mechanic: catmastertech, Technician replied 7 years ago

Download the parts images from the link below.

http://1drv.ms/1CqSNLL

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Customer reply replied 7 years ago
We have a diagram on our sis caterpillar system but the image we want is the transmission shaft with all the parts in on it and the numbers because we can not see that diagram
Mechanic: catmastertech, Technician replied 7 years ago

Can you zoom in on the images I sent you?

When I click on the planetary image, it will zoom in and is very clear.

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Customer reply replied 7 years ago
Can you send an Emil address were I can send you the picture of the shaft
Mechanic: catmastertech, Technician replied 7 years ago

All contact is limited to this site per policy.

If you cannot upload the image through the upload / edit functions on the toolbar here, use a cloud or online drive or a picture account and send me a link just like the link I sent you.

I used OneDrive and posted the image in my public folder. Then you can create a share link and post is here.

I also use Dropbox and have seen others use Flicker. Just look for the online storage option and then share to create a link to the image.

It usually works better than the upload edit function on this site.

I must leave for work now so, my reply my be later in the day.

I will try to respond during a break if I can get online.

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Customer reply replied 7 years ago
Hi I am having D4 D bull Dozer 60J 2585 I want to know which year it was made
Thanks Terry.
Mechanic: catmastertech, Technician replied 7 years ago
Your tractor was made in 1971.
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Customer reply replied 7 years ago
How about the year for the D6 C bull Dozer 47J 4195
Mechanic: catmastertech, Technician replied 7 years ago
1975
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Category: Construction and Road Equipment
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