1994 M1089 wrecker hydraulic issue

[farahmichael]

Anyone familiar with the operation of these trucks? Recently purchased a 94’ M1089 with 700 miles and a main boom that would not operate. Turns out it will go up but only if the slave external power system switch is moved from normal to “supply external power”. Will not do down in any configuration. Not even by using the manual pump. Tried remote control, nothing. Everything else works fine. No leaks, feels like it has pressure at the valve. I don’t know what the slave system is doing to imagine a diagnosis.

Valves:

Control panel:

Action shot for good measure:

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[coachgeo]

do you have the TM's (technical manuals) which includes an operation manual? see the very top of page's menu.... far right is..... "TM"

as you go thru manual look real close for where hoses attach. would not be first time there is two swapped.

 

[Suprman]

On the 1084 there are function lockout solenoids. For the overload system. And outrigger up lockouts. Try unplugging them.

 

[farahmichael]

On the 1084 there are function lockout solenoids. For the overload system. And outrigger up lockouts. Try unplugging them.

Good to know. Are those located in the main electric control box for the hydraulic system?


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[Suprman]

On the 1084 they are on the manifold at each function. And there is a bank lockout for the upper controls.

 

[Mullaney]

Anyone familiar with the operation of these trucks? Recently purchased a 94’ M1089 with 700 miles and a main boom that would not operate. Turns out it will go up but only if the slave external power system switch is moved from normal to “supply external power”. Will not do down in any configuration. Not even by using the manual pump. Tried remote control, nothing. Everything else works fine. No leaks, feels like it has pressure at the valve. I don’t know what the slave system is doing to imagine a diagnosis.

Valves:

Control panel:

Action shot for good measure:

Sent from my iPhone using Tapatalk

Hi farahmichael , Could you snap a couple of pictures of your '94 model M1089 please? I have a '96 and it has no markings at all on the handles. Guessing it sat in the boiling hot sun and "cooked" off the markings. Hopefully a few closeup pictures might make it possible for me to replace the marking.

Tim
.