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Lull 644-844-1044 Highlander Won't Move

Yogie

New Member
Joined
Oct 6, 2019
Messages
2
Location
Texas
Good afternoon,
I wanted to reach out to you all about a Lull telehandler that I have just purchased. The serial number is D0988TN, and based off of everything that I am finding online. The unit seems to be built prior to 1985.

The unit starts up without any issues, idles with any knocking/ major blow by on the engine. The engine shows to be a Deutz F5L912 73.5 HP @ 2300 RPM.

The transmission shifts through all of its gears without any hesitation or grinding. The transmission is a 4 speed powershift Funk .

The driveline/linkage like that connects makes the unit a 4WD has been removed. In speaking with the seller they stated that it was removed due to the unit not working properly when in 4WD.

The hydraulic system seems to be strong and works very well. It just has a few minor leaks.

The engine slightly bogs down when I rev it up, and engage the hydraulics. It does not stall out, and seems normal to me.

However, I have had the unit fail to be able to climb up a slight incline in either forward/reverse on multiple occasions. I have seen where previous members have mentioned that they are unable to get their Lull to even be able to go up a slight incline. They mention the issue publicly, but never seem to continue the conversation or comment on a resolution to their issue. Both times that the people have mentioned having the issue, they also mention previously having cylinder work done. Initially I throughly hydraulic cylinder work, but my father in laws first instinct was engine cylinders.

The unit seems to get a “dead pedal” when this issue is happening. Even when pressing the accelerator pedal all the way to the floor. The engine does not rev up, and there is no response/increase in RPM.

The injector pump is a Bosch PES5A800410/3RS2526 0400 865 019

The unit does not even have enough power to idle up the incline once the issue starts. I was able to unload a few items immediately after starting it up yesterday. We backed up, turned, and drove up a similar incline as to what is causing the unit to “stall”. Once we unloaded the box blade, we shifted through all of the gears as we went down the slight decline.

After the unit had been running for around 15 minutes or so. We went to unload another item in the same location and the issues started again.

I have checked the transmission fluid, and it seems like it was recently replaced, and is slightly over filled. Beyond that it looks to be fine.

Any insight that you all can provide will be greatly appreciated.

Thanks in advance,
Andrew

Bosch Injector Pump.jpg Deutz Engine.jpg Lull Data Plate.jpg
 

tractormech

Senior Member
Joined
Feb 19, 2015
Messages
349
Location
florida
Questions- Does it pull good sometimes and then the travel gets weak,or is the problem immediate? does the engine sound like it's laboring when this occurs? If there's an internal valve leak it can keep the pump "loaded" and it will absolutely KILL the power from the engine and it won't pull for anything. Do you hear rapid pulsing or see any hoses jumping or hear hissing noises? That indicates internal leakage. It won't be a cylinder if it does it without operating any hydraulic function. Is this machine pilot control with joysticks or manual levers operating the valve? If the accumulator is bad and leaking down it will make the pump cycle trying to keep accumulator pressure up to operate brakes and whatnot. Take some pics of the pump.valves and see if there's a control manifold block also. We'll try to help you out.
 

cjdoyle42

New Member
Joined
Dec 30, 2023
Messages
2
Location
IOWA
Lull 644b-37 jan96v12n17-275
When you start the unit it will have a brake light on for about 20 seconds. As soon as the brake light turns off it sounds like it’s deadheading hydraulics. It won’t drive unless I operate the hydraulics.
 
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