784 No power steering

[IHEyeguy]

I was brushhogging yesterday and all of a sudden I had no power steering. The steering wheel just turns with absolutely no motion on the front end. If I
use the remotes the steering shows some resistance but still no motion on front end. I even lifted the front end off of the ground with the loader and it
didn't budge. I checked the flow divider and it was kinda stuck but I got it out and it went back in with no problem. Seems to move easily. I am thinking
my steering hand pump is shot. What do you think? Thanks for the help.

 

[the tractor vet]

I am more on the side of the MCV with sticking flow divider valve . BUT myself i would need to put either my flow rater on it or some gauges . . Did you change Hyd. filter yet ??

 

[Mrfred54]

Do all other hydraulic functions work?? Maybe steering relief valve stuck! Its in the MCV

 

[IHEyeguy]

As far as I can tell everything else is working. I need to check the 3 pt and make sure it is functioning properly. I'll check into the steering relief valve. Thanks.

 

[IHEyeguy]

Should the flow divider just fall out when you remove the nut or should it require a little coaxing to get it out? I have changed the hydraulic fluid and filter several times in the last 10 years. I don't put a lot of hours on my tractor. I still work full time and just pretend to be a farmer on the weekends. If you think it would help, I could definitely change the filter.

 

[JimB2]

Hi, see attached photo, most likely your 784 doesn't have the FWD/REV option so the upper left outlet will go to the oil cooler.
The power steering pressure line should have 1200 to 1500 PSI and a flow of 3 GPM.

 

[IHEyeguy]

Can you tell if this power steering relief valve is stuck. It looks to me like someone has worked on it before because it has tool marks.

 

[caterpillar guy]

I would start with the filter then check for pressure at the remotes if no pressure you have either a bad pump or a bad valve in the MCV most likely the valve if everything else seems to work. Then next would be to check flows and pressures at flow volumes or flow volumes at pressure if you can get the pressure. If either show up to be low it is the pump. IF you get both flow volume and pressure then it is most likely the relief valve in the steering or oil cooler is a problem with the flow through it. Don't remember just the detail but the flow from or to the oil cooler affects the steering.

 

[the tractor vet]

Somebody was playen , they are staked pretty good . . And yes the reg. valve should float free .

 

[IHEyeguy]

Update: Everything hydraulic checked out fine. Turns out it was the power steering cylinder that blew out. Put a new one on and now she works great! Thank you all for your help and ideas!