Model 770 Front Loader Problem

[Anonymous-0]

I have a model 770 Tractor that just recently started exhibiting problems with the front loader (Model 70) where one can tilt the bucket but unable to raise it. It's almost as if the hydraulic fluid is some how bypassing the piston which raises the bucket. Any ideas as to what could be causing this problem?

 

[F-I-T]

Switch oultets around and try it. You could have lost a pin in the linkage to the 4 way valve.

 

[FAaron3]

I will take a look at the valve (under the seat) - should note that it raises about 18 inches and makes a squealing sound. So, one should assume that some fluid is getting to the piston.

 

[DONMYEIL]

I dont know this loader but check for a bad hose coupler and/or valve thats not turned on. Sounds like oil is trying to flow past a restriction. check the source of the squeel and you will find the problem.

 

[F-I-T]

Important information, but again, switch outlets (swap dump for lift and lift for dump) and you will know of the loader cylinders are in question or if it in the oil supply, without assuming anything.

 

[FAaron3]

Just curious why would the oil supply be in question or how could it be contributing the problem. As I understand - a pump is located in the transmission which supplys the force necessary to lift the box blade attachment on the rear and the front loader. We are not having any issues raising or tilt/roll the box blade cutter on the rear. The problem is retricted to lifting the front end loader. We will swtich the lines and see what happens. Would you have any suggestions as to how one might lift the front loader so that it might be loaded on the trailer and transported to the John Deere Dealership if the line switching does not work.

 

[F-I-T]

Just try switching lines first. How tough can it be to walk outside and swap lines? If the tractor is where you are located, you'd have eliminated a lot of questions by now. Another tractor and a boom will lift the loader, or tilting the bucket up and backing onto a trailer should work as well.

If all other hydraulic functions are satisfactory, the problem is likely in one of the ports or the 4 way valve, or valve linkage. I had one a while back spit an o-ring out of the Pioineer type coupler and it ended up in a relief valve, but that would affect all functions. You proably just have a bad female coupling half that will need rebuilt or replaced. It can happen. They sell those every day.