Backhoe Backhoe Questions

[SPIKER]

slorne:
sorry about the blown pump: #1 reason i suggested setting up a pressure gauge inline... anyhow

#2 there should be an o-ring under the small metal bracket/hose fitting on eash side of the pump between the 4 bolts that hold the fitting to the pump and the fitting. there is a grove cut in them. all of the hoses have o-rings between the hoses and the flat mating surface of the cylinders & fittings too.

more than likely the pump was damaged prior to the PV blow out. the metal more than likely came form the pump? had to come from someplace. I would removing the pump inl;et & outle hoses and cleaning them inside with flush & air. same for tank if possable use long magnetic pickup tool to forage for debris. dissassemble the valves and do the same for them if (IF) you find much more than flakes the sice of metal flake paint.

keep up the work it will be rewarding SOMEDAY /forums/images/graemlins/smile.gif

MarkM

 

[schmalts]

**** that sucks. I knew you would find crap in the PR valve from the other things you told me(fluid moving in tank)
It is possible that you replaced the PR valve and had screwed it in all the way or too far. Like i said, if you dont have a guage dont worry about doing it the way i said, you cannot hurt anything by having it set too light.
Start with the PR valve set almost all the way out, then work the outiggers until they just have enough power to lift the tractor off the ground. do small incriments until you achieve this. Then go have a little fun and if you find the hoe is not able to dig like it should make small adjustments. Remember, skill is everything with hoe operation. if you never used one before dont attempt to just push the bucket into the ground because everything is done by touching the bucket down, then pulling the main boom towards you to fill the bucket about half way, then curl the bucket and it will fill the rest of the way. That is the proper low stress way to work it.
Do you need a spare pump?

 

[Boltonpower]

Suggest the following:

1) Take the dead pump apart and see there is any
indication that it took a piece of metal from
the suction side.

2) Drain tank (if you haven't done this) and remove
the suction strainer. Check to make sure it isn't
compromised somehow.

3) I would have a "Tee" made up to test the pressure
since there seems to be some question about what it is.
The fittings on the pump are Seal LOC type 18mm X 1.5mm
You can guess if you want but you risk a hydrualic
explosion if it's way to high. The system is rated at
16 mPa or about 2,300 psi. I wouldn't screw with that.

4) After putting the gauge "Tee" in line I'd back off the
cap nut on the underside of the PR valve and with
the tank filled so you can see the oil start the engine.
watch the gauge carefully. The 2,300 is max so at idle
it maybe a little less.

5) watch the gauge carefully and crank the cap nut in. The
pressure should rise. The oil should be moving from the
right side of your tank to the left. I'd set it at about
2,000 psi max.

6) After you know you have good pressure and flow in the
valve gallery then you can test for issues with the
induvidual spools. Lets get that going and safe first.

Yes I do service. I'm in central Mass, where is your fathers tractor??

Graham

 

[JohnS]

I am surprised that it didn't just blow the pump seal, like on the engine mounted pump (very similiar design). That casing is fairly thick. Went through to the bolt hole and out.

Did it stall or load down the engine significantly? When you dead head the engine mounted pump, it will load or stall engine.

 

[slorne]

John,

I have given alot of tought to what happend with the pump after I found the metal shavings and cleaned out the PR valve. I'll list what I think happend:

1) Cleaned out the PV, which was definitly the problem

2) Started, enguaged PTO and tried moving stablizers

3) They moved - lifted bh off the ground

4) Then they did not work the second time

5) I slightly tightened PV - thinking there was an inital burst of fluid, but then not enough pressure

6) Nothing - So I turned up the RPM's - and bang

I think the error was probably the following

1) too much pressure (PV too tight to begin with)

2) First action from stablizers was a result of the metal shaving being removed and fluid flowed briefly

3) Tightening and increasing rpm overloaded the system

Tomorrow I will clean all controls, the tank, filter, replace all fluid. Then start with a very loose pv (tight enough not to fall off) and slightly tighten. I will be very careful and tighten slowly and wait (patience)

Although the crack looks like it's through the bolt hole, it is not. It's only through the casing and the face plate with 4 bolt holes has no crack.

No drop in rpm or strain on the engine when the bang occured. It only started pumping fluid out of the crack like a waterfall.

Also, no sign of broken metal in pump or gears. Although the gears look like something could have scuffed them. I will post detailed photo's after I get this thing figured out.

Once again, I am greatful for everyones help and sincerely could not have assembled, trouble shooted this tractor with out everyones support.

Regards-

 

[slorne]

Left something out

6) Nothing - So I turned up the RPM's / AND TRIED TO MOVE THE BOOM - and bang

 

[slorne]

All,

Well I am pleased to report the whole issue is fixed. I will do a quick write up with photo's for John to post on BH installation, if he is interested.

Here's a summary of what the problem was:

1) No bh operation was a result of metal shavings in the PV

2) After cleaning the PV, I had the pressure set too high and later found out there were a heck of a lot of metal shavings in the fluid tank and each hydraulic line (bled each line)

3) The other big problem I had was that the bh ships with a pin in the boom to lock it in place
-I did not remove the pin and when I tried the boom (after correcting the pv issue), I think the pin and the high pressure caused the pump to blow

Although this issue took me a week, in my spare time, and cost about $100, I learned the following:

1) Always remove the pin in the bh boom after assembly and before trying operation (I was a dumb ****)

2) I found almost a hand full of metal shavings in the fluid tank, no kidding
-I used a big rubber coated magnet and a two foot flexable piece of spring connected to the magnet (about 1/2 inch thick) to completely clean all the metal shavings out of the tank

It almost seemes like the tank was under a drill press and alot of shavings fell into the tank during manufacturing. Also, make sure to clean the screen filter well as there was metal shavings inside the filter.

Once again, I am greatful to everyone who helped me with this issue.

Thanks Again-

slorne

 

[bluechip]

Be sure to adjust your PR valve, moving the boom with the pin in place should not blow the pump but should hit the PR valve, makes sort of a buzz/screach type noise.

 

[JohnS]

Glad to hear it all worked out. Thanks for letting us know about the pin. I didn't understand when the PV was cranked down, why the rams didn't move. /forums/images/graemlins/wink.gif

 

[mark1]

Hi Just a quick note about the "Storage pin" The pin is great for keeping the boom in position when not in use.BUT DO not slip the pin in the hole of the boom when in use.I looks like a good place to keep it.But it will crush the steel hyd.line on the boom cylinder when using the hoe. This was written up a while back in the NYCTOA site. /forums/images/graemlins/shocked.gif