Quickie loader, very slow. WHY?

[jahmes143]

On a 1997 Kubota M5400 with 800 hours.

Curl up/down is slow, lift is slow, lower is normal speed, breakout force seems weak too. No leaks or leakdowns.

Changing fluid/filters didn't help.

I just inherited this very clean tractor and don't know a lot about hydraulics. I presume I should start by looking at the loader valve??? But what do I check?

It's a Quickie 310.

 

[Tx Jim]

Diameter of cylinders affects cylinder operational speed combined with hyd pump output in GPM's. Be sure 3pt hitch relieve valve isn't by passing fluid from 3 pt attempting to raise up higher IE move 3pt control lever 1/2-1'' forward. Do you have any idea if loader control valve is attached to tractor hyd system correctly?

 

[mikester]

Quikie loader

Slowie tractor

 

[Roadworthy]

I'll go along with TxJim. Be sure your three point lever is not quite in the full up position. If that solves your problem your rock shaft probably needs adjusted.

 

[agjones]

The 3pt lift advice is good.

Mine will also do this when I knock a rear remote into detente. Not enough draw to humble the tractor but it does gobble up system flow so everything acts weak

 

[arthurjohnston]

I would suggest checking a control valve because its malfunctioning can cause slow operation. Ensure that the valve is functioning correctly and not obstructed.

 

[rScotty]

On a 1997 Kubota M5400 with 800 hours.

Curl up/down is slow, lift is slow, lower is normal speed, breakout force seems weak too. No leaks or leakdowns.

Changing fluid/filters didn't help.

I just inherited this very clean tractor and don't know a lot about hydraulics. I presume I should start by looking at the loader valve??? But what do I check?

It's a Quickie 310.

That is a wonderful tractor and top of the line loader. You have a classic and still as good as any tractor made. Or better. Good for a lifetime. Don't let anyone pry it away....

There isn't really anything to look at in a loader valve other than the pressure of the relief setting. With no leaks or leakdowns that pretty much eliminates the loader valve itself

If you really want to diagnose anything with hydraulics - including the relief valve in the loader control valve set, you will need a pressure guage kit. Amazon has them for inexpensive. Needs to read to 5000 psi.

Always good to change fluid and filters. I hope you got OEM hydraulic filters - that's another thing you can check at least partly with the pressure gauge.
Also, next time you run it long enough to get it warm, take a look at the hydraulic oil and see if it is clear or cloudy or foamy. If not clear, it is probably a simple suction line air leak - but it must be fixed.

If you just want to guess at something to improve things....there is a possibility you can try that can be done with simple hand tools, look at the diagram and replace all the O rings - parts 050 (3) and 080 in the steel suction line. Yes, you will probably need kubota O rings to fit the metric tubing.
A pressure guage kit would diagnose a leak here too - but takes some experience....although anyone can do a crude test for air leak by checking for wetness or looseness on pipes 040 & 070. Or wind some electrical tape over joints where it might suck air.
You can order filters and parts online at messicks.com.
luck,
rScotty

 

[jahmes143]

I'll go along with TxJim. Be sure your three point lever is not quite in the full up position. If that solves your problem your rock shaft probably needs adjusted.

Thanks for the tip. Tested today and the loader is same speed (slow) regardless of 3p position.


@rScotty Thanks for all the tips and diagram. I used Wix filters and Harvest King fluid meeting Super UDT specs. Is this a no-no? Fluid stays clear, no air. I see you're in CO. Whereabouts? I'm near-ish Delta.

 

[rScotty]

Thanks for the tip. Tested today and the loader is same speed (slow) regardless of 3p position.


@rScotty Thanks for all the tips and diagram. I used Wix filters and Harvest King fluid meeting Super UDT specs. Is this a no-no? Fluid stays clear, no air. I see you're in CO. Whereabouts? I'm near-ish Delta.

I don't think those filters and fluid are the problem. They are good enough.
Next guess when all the systems are slow is that one of the relief valves has some crud in it.
You could look through the hydraulic diagram and try to guess which one it would be, but to pin it down
requires some gauges.
Right now we don't even know if the system is making pressure.

 

[jahmes143]

I don't think those filters and fluid are the problem. They are good enough.
Next guess when all the systems are slow is that one of the relief valves has some crud in it.
You could look through the hydraulic diagram and try to guess which one it would be, but to pin it down
requires some gauges.
Right now we don't even know if the system is making pressure.

Pressure gauges ordered. Will report back next week.

 

[jahmes143]

Update...I removed the fill cap with tractor running and do faintly hear a slight bit of frothing sound. Perhaps see a few air bubbles on dipstick but hard to tell (will add oil dye next week and see if it makes bubbles show up easier.

Tractor doesn't have rear remote, so no detent to get stuck.

No oil leaks/seeps anywhere, so not sure whether the potential air leak is coming from.

 

[rScotty]

Pressure gauges ordered. Will report back next week.

Nice. I'll look forward to working on it with you.

If you want to try something while you are waiting, go back up to post #7 and look at the that hydraulic diagram. Do you see the two joints in the suction pipe where the 050 O rings are used? Get in there with some stretchy rubbery electrical tape or some stretch & seal self-fusing silicone tape or maybe just some silicone gasket goo and wrap the outside of those two joints.
Don't take them apart, that would be a mess. Just try to seal around the outside with something easy to remove and see it that helps...

I never have fully trusted that method of "O rings comressed on a steel tube" that Kubuta uses there.
rScotty

 

[jahmes143]

@rScotty Gauges came in today. Pressure is reading ~2500psi. I was able to rubber tape one of the 050 o-rings (at the joint of 2 steel tubes), but no real clearance to get tape around the joint by 050 joint by the filters.

Looking for air bubbles...maybe maybe one here or there, but definitely not foamy at top of dipstick or anything.

Loader is still extremely slow.

Is there a way to test whether air is getting in on the suction side?

Should I check for anything else?

 

[rScotty]

@rScotty Gauges came in today. Pressure is reading ~2500psi. I was able to rubber tape one of the 050 o-rings (at the joint of 2 steel tubes), but no real clearance to get tape around the joint by 050 joint by the filters.

Looking for air bubbles...maybe maybe one here or there, but definitely not foamy at top of dipstick or anything.

Loader is still extremely slow.

Is there a way to test whether air is getting in on the suction side?

Should I check for anything else?

Darn....I was hoping for a suction leak, but OK. It is sounding like it isn't a suction leak, so next we look for a flow restriction. Basically the procedure is to insert the adapter T with its gauge everywhere we can by interrupting every hose we can - starting with the pump to the FEL {IN) port.
While the T is in line we work the hydraulic controls - and hope we see a reading on the gauge that we can't explain.

Where is the gauge adapter inserted now to get the 2500 psi? I'm assuming that you are using one of the "T" adapters in the set so that the adapter is in series with one of the hydraulic hoses. And also that the gauge is on one leg of the "T", right? Is that how it is?

However it is hooked up, let me knowwhere you have that "T" adapter plumbed: And it makes sense each location to note what else was goiing on and the pressure as the FEL is Raising, Lowering, Straining in overload, or just sitting there...

 

[jahmes143]

@rScotty Yes, it's plumbed how you described, with the T in series and gauge on one leg. T is located very close to fuel filter...on the "passenger" side near loader valve. T is screwed into a welded port on the cylinder barrel very near where the rod comes out of the cylinder. Pressure is 0 under no load and remains 0 during all functions of the FEL other than it spikes to, and stays at, 2500 when bucket touches ground and raises front wheels off ground.

 

[oldnslo]

Have you timed the cylinder movement - velocity to determine actual flow rate. If not I would do that as a baseline to determine actual flow rate vs it seems slow.

To do this you need to pick an engine RPM for all of the velocity tests.

You will need to know cylinder diameter for this.

Formula for figuring flow based on velocity is: Flow = cylinder velocity times cylinder area. This provides flow based on operation of a single cylinder. For a typical loader you are operating 2 cylinders so divide calculated flow by 2 to get actual pump flow.

Since cylinder area in expressed in square inches I find it is the easiest to convert velocity to inches per second and to cubic inches per second.

NOTE: Measure the actual cylinder movement and not loader movement

 

[jahmes143]

@oldnslo I have not timed flow rates. Starting at full curl up, it takes about 10 seconds to get to full curl down. My redneck math says that's very slow.

 

[oldnslo]

@oldnslo I have not timed flow rates. Starting at full curl up, it takes about 10 seconds to get to full curl down. My redneck math says that's very slow.

I agree that does sound slow but reason for inquiry on flow is the flow = speed while pressure = force. I presume raise and curl are equally slow ( can’t remember what has been posted)

RScotty method of taking pressure readings will tell you if there is a restriction potentially limiting flow.

Your post on no pressure till bucket movement is restricted points towards no restriction in that portion of the circuit

 

[jahmes143]

@oldnslo lowering operates normal speed. Raise & curl up/down are all 3 very slow. Thinking I'll get an in-line flow meter to test gpm flow rates. Found a good Omega on ebay for $100 OMEGA OIL FLOW METER 25 GPM 1 NPT HIGH FLMH-1025BR-HT PCCLR07536 3500PSI | eBay

 

[oldnslo]

Lower speed is probably gravity so that makes sense. Flow meter is a nice tool in the tool box for problems like this. Is there space to install it in the pressure line from the pump?