Ford 5000 Hydraulic Problem Solved...Maybe

[Dave3]

Did you completely drain the rear axle housing to get any sludge or water out
How much hydraulic fluid did you add to refill the axle, it should have been filled until fluid started coming out of the check plug hole
Originally you had a non oil flow is effecting both the lift and pto (pto drive not turning, plugged suction screen, failed pump), beyond the pump both systems are separate.
Now you have a lift control issue, usually this is caused by a sticking control valve, sticking unloader valve or something in the draft control spring linkage forcing the lift control into lift position
Do you have any type of repair manual such as I&T or factory service manual, or are you googling and utubing for information on how to make repairs

Yes, I drained it three times wrestling with the hydraulic pump install. It is rare my repairs are successful with one try. LOL I refilled until it started coming out of the check plug hole on the side of the tractor. I have a repair manual but it is not always clear or easy to understand. I have watched a few Youtube videos. I got most of my pastures mowed before the lift got stuck. Finished them with a 1949 Ford 8N. Hard to break those tractors! I'm going to take the top cover off in the next few weeks. I will post pictures of the process and what I see inside. I hope it goes well. If it does it will give me confidence to split it and install a new clutch. Tired of hearing the grinding sound...thanks for the help!

 

[Dave3]

Took the top cover off today. Very heavy! I thought it only weighed around 120 lbs. I had to get the engine hoist to lift it off. Glad I knew it was 15 bolts. That last bolt does hide.
First problem was the amount of black sludge. Very thick and sticky. Also, the last guy who took off the top cover used silicon to seal it back in place! I will try and upload two videos. One video I call a valve an uploader valve, but I believe it is the control valve. It would not move when we first moved the lift control handle up and down. After a few moving the handle a few times it popped loose. I think this is why my lift arms would not move down. Correct? Can anyone tell if anything looks obviously wrong by the pictures?

 

[Dave3]

See attached video. I believe this is the control valve.

 

[Dave3]

Lots of black stick sludge could have also been the problem!

 

[Destroked 450]

First video the linkage is connected to the control valve which was apparently stuck
The unloader valve is next to the control valve and is hydraulically activated by the control valve
Remove that tin plate on the back of the valve body to access both valves
There’s a plug with a threaded bolt hole that must be removed to remove the unloader valve
Remove only the valves to clean the valves and bores, no need to remove any other components
Once cleaned and reassembled follow the service manual to adjust draft and position control linkages before reinstalling the lift top
I’m not sure if a new top gasket is still available, I use RTV but not the blue or red stuff, Ultra gray or Ultra black are my go to sealer
John Deere has a white sealer that’s really good

 

[Dave3]

Thank you Destroked450!
I will do what you said with both valves. Anything else I should check while it is off? Should the rings on the hydraulic piston be changed?
I think I will use Ultra Black RTV. I'm sure there is a reason the last person used silicon on the lid. The surface might not be completely flat or something...I have had new gaskets fail on these old tractors.

 

[Destroked 450]

While the top is off it would be a good time to replace the lift piston o-ring

 

[Dave3]

Will do! Hopefully have time to do it this weekend.

 

[Dave3]

I got the hydraulic cylinder housing separated from the top cover! Lots of cleaning to do! This is the best video I found on how to clean and replace O-rings in the housing.

The cylinder only had the rubber gasket. Many of the O-rings looked distorted. The control valve would not move.

 

[Destroked 450]

That video shows complete tear down, I never remove the control valve and unloader valve bushings, these are sized to fit and no longer available if damaged during removal or reassembly
Check the cylinder bore for scoring, minor honing can be done but not with a course stone hone, I prefer 240-320 grit stones as courser stones like 120 leave micro scratches that wear away the rubber o-ring faster
Once everything is reassembled make sure to check draft and position control linkage adjustments before reinstalling the lift top

 

[Dave3]

Will do! Thanks!

 

[Dave3]

What is a good solution to use to clean the sludge out of the top cover and hydraulic fluid reservoir? Would CRC brake cleaner work or kerosene? Need something to dissolve the sludge but not the O-rings.

 

[Dave3]

Looking for something I can spray into the control valve and unloader valve housing that will remove any junk/sludge. I agree with you, I don't want to take it apart!

 

[Destroked 450]

You want to pull the valve out to clean them but not the bushings, you will have to pull the unloader valve plug to access it
Brake clean is good for the valve housing but it would take a lot to clean the sump, if you have a small hand sprayer I’d use kerosene or even a 50/50 mix of gas and diesel

 

[Dave3]

Thanks! I will give it a shot this weekend.

 

[Dave3]

Update. Ran the tractor and mower for 6 hours with no problems. Lift went up and down and PTO spun like a champ! Then suddenly the lift arms dropped the mower all the way down and would not come back up. Turned it off and let it cool down for a few hours. It would then lift the mower only halfway and very slowly. Put a hydraulic gauge on it and only got 1000 PSI.
I put on a new hydraulic pump last year. Also took off the top cover last year and cleaned everything thoroughly. New intake filter.
Could this already be the China made pump going bad? Relief valve stuck open?

 

[Dave3]

Hydraulic relief valve was stuck.