Hydraulic Help

[etpm]

Recently my son was working on a small dozer. He removed and replaced a hydraulic motor. The dozer track wouldn't move. The problem was that when he pushed the coupling over a shaft the leading edge of the woodruff key in the shaft caught on the coupling and so the key was pushed out of the shaft keyway. Does your setup use a woodruff key?
Eric

 

[Scott Y]

No standard keys, but Thanks for the input.

 

[oldnslo]

As viewed facing front of tractor drive coupling is turning clockwise and bottom gear is driven gear the pump inlet would be on your right. Is this how it is plumbed?

If top gear is driven gear pump inlet would be on your left.

 

[Scott Y]

Update: problem resolved, My mistake, stupid as it is, I own it, restriction in reservoir so not adequate flow to pump, I purchased the reservoir a long time before all the other hydraulic components, I took it out of the box to look it over, before putting back in the box I put blue shop wipes in all the openings, 9 months later started the project, I looked in the reservoir thru the outlet bung hole, did not see anything inside, guess what there was a shop towel in there, did not think flow was my issue at first since I blew hydraulic fluid all over side of tractor when I plugged line from pump with my thumb, towards the end of all of this the rag totally plugged the 90 degree elbow coming out of tank, your guys replies led me back to this , so I Thank You Very Much, some times it is hard to see the forest thru the trees, I am just glad it is working, Winter is knocking at the door, You guys all pick a place in the middle and I would buy a beverage of your choice. Thanks and Have a Very Happy Holiday!!!

 

[ptsg]

Update: problem resolved, My mistake, stupid as it is, I own it, restriction in reservoir so not adequate flow to pump, I purchased the reservoir a long time before all the other hydraulic components, I took it out of the box to look it over, before putting back in the box I put blue shop wipes in all the openings, 9 months later started the project, I looked in the reservoir thru the outlet bung hole, did not see anything inside, guess what there was a shop towel in there, did not think flow was my issue at first since I blew hydraulic fluid all over side of tractor when I plugged line from pump with my thumb, towards the end of all of this the rag totally plugged the 90 degree elbow coming out of tank, your guys replies led me back to this , so I Thank You Very Much, some times it is hard to see the forest thru the trees, I am just glad it is working, Winter is knocking at the door, You guys all pick a place in the middle and I would buy a beverage of your choice. Thanks and Have a Very Happy Holiday!!!

Great news. At least it was an easy and cheap fix.

 

[LD1]

Love a good resolution. Glad you found it.

Reminds me of about a year ago I was replacing a powersteering pump on a 05 ford powerstroke. New one from Napa had a plastic plug in the little suction tube to keep dirt out (and assembly lube in). And a threaded plastic plug in the pressure port. That one was obvious because it had to be removed to thread in the pressure hose/fitting. But the suction tube....the hose just slips right over it even with the plastic plug still in place. Usually these plugs are a bright color and stand out....like red or yellow. But this one was painted over black like the rest of the pump. Took a minute to figure out why the new pump wasnt working....lol.

 

[PILOON]

Thanks for keeping us advised of the successful conclusion, (so few don't).
Also bravo to admitting the cause.

 

[mrmikey]

Good show Scott, told u it'd be something simple , least ways you didn't suck the rag into the pump...............Mike

 

[jonsstihl]

in aviation we use bright colored caps that extend beyond the hole (we call them baseball caps) so they are easier to see.

Glad to hear it was something simple and easy to fix and that it probably didn't do much damage.

 

[leonz]

Where are the three return lines from the functions?
That is the first question I have as they should be attached
to one of the three spool valves in the correct position for return flow.

 

[leonz]

First off you never adjust a relief valve without a proper hydraulic gauge.

In a gear pump the oil flows around the gears from the inlet/suction side to the outlet side not through them.
After the oil leaves the pump the resistance created by the spool valve or hydraulic motor under load creates pressure in the hydraulic system.

Can you please provide more detail exactly as to what type of spool valve you have there as it is very important.

Your description of the valve is very odd as a spool valve can be open center, closed center, open center with single detent,
open with dual detent or a pilot operated open center spool valve. There are others but for now let's concentrate on what you have.

I have never seen a 4 position open center valve on the mining equipment I operated or repaired they have always been spring centered
open center valves or single detent spool valves.

You have 3 sets of quick connects; where are the 6 hoses that attach to them?? you have to have them connected to a function for the valves
to work and not dump oil under pressure back to the return line to the tank.

If your oil tank has a baffle plate the return oil is stopped and held long enough to cool to some extent before the oil is pulled out by the gear pump.

You will not see any agitated oil until you connect the six hoses and operate one or all three of the valves separately.

 

[LD1]

Where are the three return lines from the functions?
That is the first question I have as they should be attached
to one of the three spool valves in the correct position for return flow.

Plumbing looks fine to me

 

[Scott Y]

In the picture the hoses to the loader are not hooked up yet, the valve bank just has the supply and return hoses hooked up, once I got the system to work I dialed in the relief setting then put loader on tractor, then the control hoses were hooked up. Thanks

 

[Scott Y]

I used a quality liquid filled gauge for setting up the relief valve, the valve is a 4 position, open center, spring return spool valve, the hoses to the cylinders do not need to be hooked up until the system is working properly, it was a snafu on my part, there was a rag in the reservoir, plugged the output fitting. Thanks