Ford 340 (1980) Hydraulic bucket control failure

[brian1911]

I have a 1980 Ford 340A Industrial.

Had a bucket control issue today while scraping snow off of the road. The front bucket snagged a concrete seam and jarred the tractor. I was in 2nd gear, good speed.

No hoses burst, no hydraulic leaks. But I lost all bucket lift and roll control. The 3 point control works fine. The bucket control stick feels slightly loose, but that "feeling" of loose might be my imagination.

What do you think the problem may be.... before I start to dig into this? I don't have much expertise on this... so my initial thought is that if there are seals inside the hydraulic controller/stick selector, maybe I blew out some internal seals/o-rings, and everything equalized on both sides of the valve?
Thanks!

 

[Harry in Ky]

Depending on just where the strain was greatest, you may have damaged one of the bucket cylinder pistons or piston seals. That could affect the operation (or non operation) of both cylinders. It's fairly easy to check for that, Raise the loader letting the bucket droop down until both bucket cylinders are fully extended. Now remove the hoses from the rod ends of both cylinders. Then try to extend the cylinders with the hydraulics. If the pistons are sound, nothing much will happen except the engine will lug down, the pressure will build, and the relief valve will squeal. If you have a piston problem you will get a blast of oil out of the damaged cylinder.

I doubt that sort of impact will adversely affect the valve, handles or linkage.

 

[rScotty]

Depending on just where the strain was greatest, you may have damaged one of the bucket cylinder pistons or piston seals. That could affect the operation (or non operation) of both cylinders. It's fairly easy to check for that, Raise the loader letting the bucket droop down until both bucket cylinders are fully extended. Now remove the hoses from the rod ends of both cylinders. Then try to extend the cylinders with the hydraulics. If the pistons are sound, nothing much will happen except the engine will lug down, the pressure will build, and the relief valve will squeal. If you have a piston problem you will get a blast of oil out of the damaged cylinder.

I doubt that sort of impact will adversely affect the valve, handles or linkage.

My guess is one or both bucket cylinders, too. They are in parallel, so if one is damaged they both won't work. I didn't understand, but am assuming that the lift arm cylinders are working?

Harry's test is NOT one you want to do inside your clean shop or anywhere that an oily mess is going to be a problem. It's a valid test and a quick one - but with a couple of things to remember:
1. Don't stand up by the FEL cylinders when you do the test.
2. Strap those rod end hoses down after you disconnect them - this is just in case you push the control lever the wrong way.
3. Ask a helper to hold your beer, and they might want to have a camera handy....

I agree it's probably not on the loader controller. There aren't any pressure seals in the one piece FEL contollers, but if your controller is segmental type then there are seals. In either type there is a kinda slight chance that the hydraulic shock damaged the relief valve(s) or check valves attached to the FEL controller - but that depends on how the Ford controller is configured. Anyway, the controller is a place to look next if Harry's test shows no damage to the cylinders.
Luck,
rScotty

 

[Sportsman762]

The 3pt is run off of a separate hydraulic system with the pump mounted in the belly of the tractor. The loader is run off of pump on the front of the engine. Harry In Ky gives good advice.

 

[brian1911]

Depending on just where the strain was greatest, you may have damaged one of the bucket cylinder pistons or piston seals. That could affect the operation (or non operation) of both cylinders. It's fairly easy to check for that, Raise the loader letting the bucket droop down until both bucket cylinders are fully extended. Now remove the hoses from the rod ends of both cylinders. Then try to extend the cylinders with the hydraulics. If the pistons are sound, nothing much will happen except the engine will lug down, the pressure will build, and the relief valve will squeal. If you have a piston problem you will get a blast of oil out of the damaged cylinder.

I doubt that sort of impact will adversely affect the valve, handles or linkage.

Much appreciated.
The lift arms are dead.
The bucket is dead.

I can try to crack open a hose fitting. Or maybe, based on the other responses, it can be as simple as a belt? I didn’t know the front and rear hydraulics worked on separate pumps.

I know cars well. But I have never really worked on tractors. So any kindergarten level advice is not an insult here.

Thanks!

 

[oldnslo]

Brian
If neither the loader lift or bucket functions operate you are correct in looking to see if the pump is actually turning since that would affect both functions. Not sure that pump is driven but suspect some form of coupling to the end of engine crank shaft.

 

[Harry in Ky]

You're going to get suggestions from all across the board until you get specific about what works and what doesn't. Your first post indicated the rear lift works fine. The problem was only with the bucket curl/dump circuit. Now you add the "lift arms are dead". What lift arms? Troubleshooting hydraulics involves details. Where does the oil supply come from to operate the loader? Tractor internal hydraulics or a separate reservoir for a front mounted pump? Lots of guesses out here and no one (other than you) knows what you actually have.

 

[brian1911]

Brian
If neither the loader lift or bucket functions operate you are correct in looking to see if the pump is actually turning since that would affect both functions. Not sure that pump is driven but suspect some form of coupling to the end of engine crank shaft.

Appreciate it.. Sounds like a logical start. Thanks for your time.

 

[TractorTech]

Agree on the front hydraulic pump being suspect by your description. You may have sheared the splines on the pump shaft or driveshaft with that jar to the system.

 

[brian1911]

Agree on the front hydraulic pump being suspect by your description. You may have sheared the splines on the pump shaft or driveshaft with that jar to the system.

Super.. I'm guessing that this will be what I need to target in on... Again.. thank you so much!