L3301d weak hydraulics (steering, loader, 3ph)

[76scoutman]

Gauge came in yesterday. I did a quick pressure test this morning to see where we were at, expecting low numbers, but was surprised to find I still had 2200-2300 psi at 1200 and 2000 rpm respectively. The pump still sounds awful so my hope now is that I have a restriction in the feed lines and low flow is the culprit.

 

[TheOldHokie]

Gauge came in yesterday. I did a quick pressure test this morning to see where we were at, expecting low numbers, but was surprised to find I still had 2200-2300 psi at 1200 and 2000 rpm respectively. The pump still sounds awful so my hope now is that I have a restriction in the feed lines and low flow is the culprit.

How did you test pressure?

Dan

 

[76scoutman]

How did you test pressure?

Dan

I installed the test gauge on the loader lower port. I didn't warm the system up much as I didnt want any more pump strain than necessairy.

 

[TheOldHokie]

I installed the test gauge on the loader lower port. I didn't warm the system up much as I didnt want any more pump strain than necessairy.

Thats not weak pressure. So explain how the loader operation is "weak".

Dan

 

[76scoutman]

Thats not weak pressure. So explain how the loader operation is "weak".

Dan

The 3ph will barely pick up the tongue of an empty 5x8 utility trailer, the steering is tight and jerky like it's not getting pressure/flow, and the FEL (without the bucket) is slow, jerky, and struggled to lift my pallet forks a few weeks ago.

In general, anything fed by hydraulics sound and feel like they're struggling.

 

[76scoutman]

Broke the hydraulic filter loose and drained a 5 gal bucket of fluid out. Fluid looked ok to me and the magnetic pickup ring in the filter had an expected amount of debris on it (IMO, original fluid with a few hundred hrs will have some anyway)

 

[old and tired]

The old L2800 and L3400 had cracks in the return hydraulic hose that had very similar issues, it was allowing air to be sucked into the system. You could only see the cracks by squeezing the return line.

The problem was bad rubber, that was changed... new ones, like yours shouldn't be effected. Any chance you might have damaged yours. It's down by your right foot..

 

[76scoutman]

The old L2800 and L3400 had cracks in the return hydraulic hose that had very similar issues, it was allowing air to be sucked into the system. You could only see the cracks by squeezing the return line.

The problem was bad rubber, that was changed... new ones, like yours shouldn't be effected. Any chance you might have damaged yours. It's down by your right foot..

I don't think so but I'll have a look at it.

 

[76scoutman]

I don't think so but I'll have a look at it.

Yea, I didn't see anything obvious on the rubber hose

 

[TheOldHokie]

The 3ph will barely pick up the tongue of an empty 5x8 utility trailer, the steering is tight and jerky like it's not getting pressure/flow, and the FEL (without the bucket) is slow, jerky, and struggled to lift my pallet forks a few weeks ago.

In general, anything fed by hydraulics sound and feel like they're struggling.

You have pressure sufficient to easily pick up any of those loads.

Thats a lot of crud in the filter. Replace the filter and also remove the suction tube I pointed out in post #13 and clean the strainer.

Dan

 

[76scoutman]

You have pressure sufficient to easily pick up any of those loads. Remove the suction tube I pointed out in post #13 and clean the strainer.

Dan

That's what I'm working on now. That pipe goes into the gearbox housing a good 3+ inches so I'm having to take multiple things apart to get it out.

 

[TheOldHokie]

That's what I'm working on now. That pipe goes into the gearbox housing a good 3+ inches so I'm having to take multiple things apart to get it out.

That 3+ inches is the strainer..

 

[76scoutman]

That 3+ inches is the strainer..

Well, not exactly....

 

[TheOldHokie]

Well, not exactly....

Is it clogged?

Dan

 

[76scoutman]

Is it clogged?

Dan

Nope. The unloader valve looks clear too.

 

[TheOldHokie]

Nope. The unloader valve looks clear too.

You had pressure sp that was a waste of time.

Now you need to focus on flow. Put it all back together wuth new oil and filters.

Then measure flow rate at the loader valve.

Dan

 

[76scoutman]

You had pressure sp that was a waste of time.

Now you need to focus on flow. Put it all back together wuth new oil and filters.

Then measure flow rate at the loader valve.

Dan

Yea, I realize that wasn't related but it took a few minutes and I was already in the area, lol.

I'll have to get a new filter on Monday and while I may catch some flack here, I'm planning to continue running the same fluid. I captured it in a clean bucket and covered it with a lid. It will get strained going back in.

I don't feel like I've found the 'smoking gun' I was looking for, so pouring any fluid back in right now doesn't seem like my next step.

Thoughts on something internal to the pump like this?

 

[TheOldHokie]

Yea, I realize that wasn't related but it took a few minutes and I was already in the area, lol.

I'll have to get a new filter on Monday and while I may catch some flack here, I'm planning to continue running the same fluid. I captured it in a clean bucket and covered it with a lid. It will get strained going back in.

I don't feel like I've found the 'smoking gun' I was looking for, so pouring any fluid back in right now doesn't seem like my next step.

Thoughts on something internal to the pump like this?

You seem to have lost both pumps so it would not be the failure in that video.

I prefer to diagnose anf follow the results rather than guess.

1. Basic flow measurement using a bucket and stopwatch
2. If good flow repeat test using a loading valve to measure flow at pressure

Proceed from there based on test results.

Dan

 

[76scoutman]

You seem to have lost both pumps so it would not be the failure in that video.

I prefer to diagnose anf follow the results rather than guess.

1. Basic flow measurement using a bucket and stopwatch
2. If good flow repeat test using a loading valve to measure flow at pressure

Proceed from there based on test results.

Dan

Which line would you recommend to test flow? Would the PB block (out) to FEL (in) work? (Top right fitting in picture)

I want a new filter before I dump fluid in and perform a flow test so I'll pause here till one day this week.

 

[Russell King]

@76scoutman and @TheOldHokie

I can’t be 100% sure but I don’t see a screen on that pickup tube, but I think I see one on theoldhokie’s picture in post #13. I doubt that it really matters since it is filtered through the spin on filter.

1) Is there a screen on either of the pick up tubes?
2) Would it make any difference if the screen is missing?

I would have excepted to see something finer that that opening size to keep larger debris out of the tube.

So I suggest that you run a string with a small piece of rag through the tube while it is off. Just to be sure it is open.