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Takeuchi TB80FR boom not raising :-(

Tb80fr

Member
Joined
Apr 6, 2015
Messages
8
Location
Australia
Hi,

I am here looking for some advice on troubleshooting a problem with a Takeuchi TB80FR excavator. I am having an issue where the boom will not raise at all. All other excavator functions/controls are fine. I am able to slew, open and close the bucket, extend, move the swivel knuckle left and right, operate the blade and track no problems. When pulling back on the control to raise the boom I get no feedback or movement. It has been working fine up until now with good power and speed. It has a few very small hydraulic weeps from the lines since I have had it but overall in pretty good condition.

After some research it "seems" to potentially be pointing at an issue with the interference safety system.

So far I have:

1. Replaced the three interference sensors located on top of the boom and have also replaced the operator safety sensor located under the arm rest inside the cabin with new ones.
2. I have also cleaned the muck off the two original interference sensors underneath the offset knuckle swivel.
3. Changed the controls to back hoe pattern (to see if there was an issue with the controller - still no response)
4. Lowered the boom to attempt to reset any interference sensors
5. Checked hydraulic fluid level ok
6. Visual check for any obvious broken wiring

It's currently located on a farm a few good hours from a service center so I am hoping that someone can point me in the right direction for further troubleshooting. Does anyone know if there is an override/reset switch for the interference system or how to test it is functioning properly? Any other places I should check to narrow down the problem? Maybe a stuck/blocked valve?

Also if anyone has a copy of the Service Repair manual that would be a great help!

I hope everyone had a great Easter Holiday.


Thanks in Advance
TB80FR.
 

uffex

Senior Member
Joined
Jan 23, 2012
Messages
4,464
Location
Lincoln UK
Occupation
Admin
Good day Tb80fr
Suggest you locate the boom main valve (follow the boom cylinder tubes back to the MCV) - Test the pilot pressure for boom raise should be 30-40 bars, you may need help to operate the machine when checking.
Kind regards
Uffex
 

mxridernrth

Well-Known Member
Joined
Apr 9, 2008
Messages
63
Location
Victoria, BC
I have manuals for the TB153FR, which should be pretty similar. You can pm me with your info and I'll send you them.

Since you say that the pattern changer has no effect, it would have to be either something in the cutoff circuit, or the main valve itself. Does the boom lower, or attempt to lower? I'm fairly certain that the limit switches don't interfere with lowering so if it doesn't do either I'd be leaning towards the main valve. It could be that the spool is stuck? You should be able to locate the valve and pull off the pilot plunger assembly and push on the spool to make sure that it moves freely from side to side.
 

BOOKREADER22

Member
Joined
Apr 3, 2015
Messages
6
Location
ky
I found Contamination from the main hydraulic pump failing causing the valve spool to stick and not move under pilot pressure. Had to clean the spool and valve housing for the loader lift, Replace Hyd. pump and filter.
 

Tb80fr

Member
Joined
Apr 6, 2015
Messages
8
Location
Australia
Thanks guys for all the help. It has given me some really good tips on where to narrow down the troubleshooting.

I manage to track down a service manual (please pm if anyone wants a copy) specific for the machine so will be testing the interference system, sensors, solenoid and relay to rule them out before opening up the main valve and spool.

Is there anything to be cautious or wary of when working with the main valve and spool? The boom is currently resting on the ground but the dozer blade is lowered lifting the machine (was done to level the machine out to lift the cabin open).

Do all other circuits de-pressurize when working on the spool? Does the whole system have to be bled again for air? Is there a lot of hydraulic fluid lost when working with these components?
 

Tb80fr

Member
Joined
Apr 6, 2015
Messages
8
Location
Australia
I found Contamination from the main hydraulic pump failing causing the valve spool to stick and not move under pilot pressure. Had to clean the spool and valve housing for the loader lift, Replace Hyd. pump and filter.

Is that a typo "Replace Hyd. pump and filter".... I am seriously hoping it is not that serious that I have to replace a hydraulic pump! I had replaced all the filters and oils 30 or so hours ago and have not seen/heard any issues with the pump. Fingers crossed.
 

stuarty1

New Member
Joined
Oct 4, 2015
Messages
1
Location
northern ireland
hi
I have a tb80fr which is also not lifting the boom i have not had a chance to have a proper look at the machine yet, my first thoughts where that it is electrical, there must be a valve which prevents the boom from hitting the cab when in the left offset position i am going to take a look for the valve and work back from that.
 

Tb80fr

Member
Joined
Apr 6, 2015
Messages
8
Location
Australia
hi
I have a tb80fr which is also not lifting the boom i have not had a chance to have a proper look at the machine yet, my first thoughts where that it is electrical, there must be a valve which prevents the boom from hitting the cab when in the left offset position i am going to take a look for the valve and work back from that.

I too am still having the issue. It's strange. I'm yet to pull any hydraulic components or spools out just yet. So far previously after pulling apart sensors and plugs we have managed to get it working. We have had trouble free running until today where it had happened again. It is very frustrating as it is intermittent as ALL other functions work, just not the boom raising. This time no success getting it working.

If you find out what causes it, I would really appreciate the info. For some reason I'm thinking it is a solenoid or relay playing up? See pics (relays inside gold box and solenoids).

Any Takeuchi reps/mechanics have any suggestions? Thanks in advance!
 

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515moto

Member
Joined
Nov 25, 2017
Messages
9
Location
Massachusett USA
was this problem ever resolved?
we have a similar issue with a tb153fr.
all functions except the blade stopped working after being parked for a week
 

mxridernrth

Well-Known Member
Joined
Apr 9, 2008
Messages
63
Location
Victoria, BC
was this problem ever resolved?
we have a similar issue with a tb153fr.
all functions except the blade stopped working after being parked for a week
Check the arm rest contact switch. I remember a broken wire near the switch some years back. Without the switch closed, you have no pilot pressure and that is the symptom you are describing.
 

515moto

Member
Joined
Nov 25, 2017
Messages
9
Location
Massachusett USA
That's my first thought too. But I should have added we have an over pressure situation where we blow the hydraulic line coming off the pump to the distribution block or what ever it's called. So I know the pump is working
 

mxridernrth

Well-Known Member
Joined
Apr 9, 2008
Messages
63
Location
Victoria, BC
That's my first thought too. But I should have added we have an over pressure situation where we blow the hydraulic line coming off the pump to the distribution block or what ever it's called. So I know the pump is working
There's more than one pump. See attached diagram. Can you confirm that there is pilot pressure i.e. to the joysticks?
 

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515moto

Member
Joined
Nov 25, 2017
Messages
9
Location
Massachusett USA
There's more than one pump. See attached diagram. Can you confirm that there is pilot pressure i.e. to the joysticks?
Can you explain how to confirm pilot pressure
Its kind of difficult to run the machine to troubleshoot - if I run it for more than a few mins something will blow form over pressuring the hydraulic system.
Man I wish you were close to Massachusetts, you seem to know whats going on
 

mxridernrth

Well-Known Member
Joined
Apr 9, 2008
Messages
63
Location
Victoria, BC
Can you explain how to confirm pilot pressure
Its kind of difficult to run the machine to troubleshoot - if I run it for more than a few mins something will blow form over pressuring the hydraulic system.
Man I wish you were close to Massachusetts, you seem to know whats going on
If you lift up the cab, you can see the small pilot lines that go into the cab for the joysticks. One of the lines is the supply line for the pilot functions. Sorry my machine isn't at home or I'd take a photo for you. Anyway, you can tee into the main distribution line and check for pressure. They are metric fittings. The pilot pressure is only around 500 psi if I recall correctly.
With regards to blowing a line, can you indicate which line it is? Maybe we can sort that out.
 

515moto

Member
Joined
Nov 25, 2017
Messages
9
Location
Massachusett USA
IMG_2134.JPG
If you lift up the cab, you can see the small pilot lines that go into the cab for the joysticks. One of the lines is the supply line for the pilot functions. Sorry my machine isn't at home or I'd take a photo for you. Anyway, you can tee into the main distribution line and check for pressure. They are metric fittings. The pilot pressure is only around 500 psi if I recall correctly.
With regards to blowing a line, can you indicate which line it is? Maybe we can sort that out.

the first line to let go was a small 3/8" line right off the pump by the 2 relays.
most recently one of the caps on the main distribution valve under the cab, broke at the allen head screw
 

515moto

Member
Joined
Nov 25, 2017
Messages
9
Location
Massachusett USA
I know its been a while - but we were able to find a local guy who had the right knowledge and tools to work on the Takeuchi.
he diagnosed some issues with with the main valve and after some disassembly found brass shavings inside. Jamming some of the valves.
After cleaning those out we were able to get some functionality back in the boom and hydraulics. But it would revert to no functionality.
we removed and disassembled the pump and found broken parts inside
So new pump, clean the main valve, and replaced all the filters, and we're back in business
with much lighter pockets...
 
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