2015 tb290 stalling out when certain functions deadheaded/maxed

[beauthemechanic]

hello all... trying to get a grasp on a new to me machine

2015 Takeuchi TB290 3500hrs


machine is stalling out when you max out certain functions..

curl bucket max in or out dead heading function and the engine dies or stalls
stick max in or out dead heading function and engine dies or stalls
blade up or down same..

checked p1 pressure on main pump and engine is dying at around 3900psi at the pump looks like this is the spec for the pump main relief

interestingly doesn't happen when you track
or max out boom or
use hydraulic thumb or turn table
has me question why or how this can happen

pop off pressure off on all affected relief valves?
load sensing or hp sensing side of pump out of adjustment?

machine is new to me and was purchased just like this
thanks for any help
beau

 

[funwithfuel]

It sounds like your flow comp in one or both pumps is stuck . Ideally, when deadheading a function your pressure remains but, the flow comp drops to reduce flow. Flow takes load off the engine. This may be electronically controlled via pwm valve or straight up mechanical. I would be looking for a service manual or maybe ar least a technical description of pump from your dealer.
If this is one of those rebranded yanmars with a naturally aspirated 3 popper, there ain't much to gain power and speed from. People get in there and start fiddling with things they don't understand and here you are.