A couple of loader hydraulic questions

[Kernopelli]

I have a ford/new holland loader valve and have blown a hydraulic hose on the loader and broke the hydraulic pump in the past. I have just been running the loader at low engine speeds since to keep the pressure low and avoid problems. I know this not a good idea to continue this and need to address the problem before I break something again ( I don't mind changing a hose now and then but replacing a $350 pump or damaging the tractor significantly by lifting too much are another story). I assume the joystick valve has a relief valve in it and that it is not working or opens at too high of pressure level. Can someone recommend how to test the relief valve? Are they usually adjustable? And can someone identify the relief valve from the picture in the following link. http://www.tractorbynet.com/forums/...97-ford-1220-fel-hydraulic-valve-img_4169.jpg

Thanks,
Darryl

 

[john_bud]

Top left of the picture on the left end. Should be a plug there for the pressure relief. Can't see where there is any room for one elsewhere.

It is usually very close to the hydraulic inlet.

The adjustable ones will have a cap you take off and a screw or nut to turn. Down (tighter) is higher pressure. Out (looser) is less pressure. You have to test it with gage. They are cheap. 0-3000 psi.

jb

 

[RonMar]

Looks like it would be across the top of that picture, as mentioned probably with a plug on one end or the other. The adjustable ones usually have a exposed nut with a locknut. Yours may be factory set using shim washers. If there is a plug on one end or the other, of the red valve body at the top of your pic, try removing it and see what is underneath. You will probably find a washer or two, a spring and a valve seat. The tension on this spring determines at what pressure the seat opens and starts to relieve pressure. If the plug sets the tension, then their will probably be some form of setscrew along the valve body that holds it at it's set point.

To check the hydraulic safety release pressure, buy a hydraulic pressure gauge with the same type fitting that your hoses on the working ports(hoses running out to cylinders) of the valve use. If you are expecting 2000 PSI, buy a 0-3000 gauge. Remove one of the hoses and screw the gauge into the port where the hose was. Before removing the hose, Make sure the loader is solidly on the ground, engine is off and no pressure is on any of the lines by working the valve to all it's positions. And of course when working with hydraulics, always wear eye protection. A jet of high pressure fluid can ruin an eyeball in short order. Place the hose you disconnect into a bucket and secure it there. This is in case you send fluid to the wrong port. If you do this a cylinder will move and the fluid forced back from the other side of the cylinder will flow out of the hose and into the bucket. Start up the tractor and try and send fluid to the port you attached the gauge to. Since the fluid has no where to go(dead headed into the gauge), you should quickly reach the safety valve opening pressure and get a wooshing sound as the fluid flows thru the safety. The pressure reading on the gauge while this is happening is the set pressure of the safety valve. Any adjustments you make can be tested in this fashion and when completed, the gauge can be removed and the hose re-attached to the working port.

If you want a permanent gauge, you will have to add a "T" onto the fluid input line into the valve and put the gauge onto the open port on the "T". With this in place, you can check the safety pressure anytime by just running a cylinder to it's end stop(full up, full down, full curl or full dump). When the cylinders reach their end stop, the safety will open and the relief pressure will be displayed. A permanent gauge also can help you estimate just how much load you are lifting.

If your pump is working OK, you should still be able to reach full pressure at lower engine RPM's, it will just take a little longer to do so as the lower RPM means it is moving less volume per minute.

 

[Kernopelli]

Thanks for the input guys. I have a 3000psi gauge already, just wasnt sure if it mattered what line I put it in and if I used the gauge to deadhead it or put it in-line. Thanks for all the info. Anyone have any input on where to purchase metal hydraulic lines for my loader? I built my loader and was surprised to not be able to fine hard lines to run down the loader arms. I ended up just using 3/8" hose and would like to replace them with metal like OEM loaders use but where the heck can a guy get them?

Thanks again
DK

 

[Farmerford]

DK:

For metal lines, Discount Hydraulic Hose has two types of metal tube fittings that do not require welding or flaring. One type (made by Eaton) connects tube to JIC 37 male flares and the other type has its own end fittings that adapt to pipe (NPT). I have used both and had good results in a 2500psi system. When you see them you wonder how the compression ferrules that go around the tube can possibly make a tight joint, but they do. I prefer the JIC "flareless" because you have access to all the JIC male fittings, and they are a little more compact than the standard "Flareless". The tube itself is available locally or from places like McMaster Carr (which is my favorite). The 1/4" tube is easy to bend, the 3/8" a bit more difficult, and the 1/2" and larger sizes are impossible to bend (properly) without a serious bender.

 

[SPYDERLK]

DK, make sure you have a relief valve before deadheading.
larry

 

[RonMar]

DK, make sure you have a relief valve before deadheading.
larry

It has to have one, testing by putting the gauge into the valve work port is just the same as running that cylinder to it's end stop or trying to lift more than the loader hydraulics can handle on that circuit. If it can't handle that, it has real design issues and would not survive very long in normal use

 

[Soundguy]

By the way... keeping rpm low only keeps the flow low.. pressure should still be the same once it runs up against an obstruction.. etc..

Soundguy

I have a ford/new holland loader valve and have blown a hydraulic hose on the loader and broke the hydraulic pump in the past. I have just been running the loader at low engine speeds since to keep the pressure low and avoid problems. I know this not a good idea to continue this and need to address the problem before I break something again ( I don't mind changing a hose now and then but replacing a $350 pump or damaging the tractor significantly by lifting too much are another story). I assume the joystick valve has a relief valve in it and that it is not working or opens at too high of pressure level. Can someone recommend how to test the relief valve? Are they usually adjustable? And can someone identify the relief valve from the picture in the following link. http://www.tractorbynet.com/forums/...97-ford-1220-fel-hydraulic-valve-img_4169.jpg

Thanks,
Darryl

 

[SPYDERLK]

It has to have one, testing by putting the gauge into the valve work port is just the same as running that cylinder to it's end stop or trying to lift more than the loader hydraulics can handle on that circuit. If it can't handle that, it has real design issues and would not survive very long in normal use

Im reading broken pump, blown hoses. Hes being careful with speed and lift because hes worried about overpressure. Dont see the relief valve. I say find it.-- then make sure it works before intentional deadheading.
larry

 

[Soundguy]

Pump pressure will be constant when under load.. flow is what will change with engine rpm..

Soundguy

 

[Kernopelli]

OK, I figured out that my control valve does not have a relief valve built in (apparently, my ford 1220 control valve relied on a relief within the tractors system). Can I buy an adjustable relief valve with 3 ports and put it inline on the "in" line before the control valve and plumb the 3rd port to a "t" in the return to tank line coming out of the joystick control. Sound reasonable?

Darryl

 

[Soundguy]

I have seen some systems use a seperate relief, similar to what you are saying.. Plumb relief port to tank/sump line.. and then plumb out of r-valve to in of loader valve.. etc. Not ideal.. but then.. WAY better than deadheading anything..

Soundguy

 

[Farmerford]

Darryl:

I put a Prince three port adjustable relief valve into a circuit like you propose and it must have opened a zillion times in the past several years without a problem. It is awkward to do the plumbing, but once installed it seems to work as well as the ones built into the pumps on my other equipment.

 

[john_bud]

go to

www.baumhydraulics.com

they have diagrams of ways to plumb.

jb

 

[RonMar]

So who assembled this combination of pump, loader, valve ect without providing for a safety relief/system pressure regulator? That is a good way to get someone hurt. A ruptured hose or pipe can spray a jet of oil that will penetrate clothing and skin causing very serious tissue injuries that will have difficulty healing.

I made some assumptions(properly engineered installation) when I made my earlier suggestions for checking system pressure. I am terribly sorry about that.

 

[Steve_Miller]

I'm going to go out on limb here and say that one of those covers on the valve is a relief. Not very often a valve like that will come with no relief, it may just be set at it's maximum relief which is also unusual. Curiousity would get he better of me and I would have it opened up by now. If your tractor has a hydraulic 3PH then the sucker would lift anything in its path with no relief on the hydraulic system.

Steve

 

[Soundguy]

I'm with ronmar on this one. Who cobbled this system up where you have a spool valve feeding from the pump with no relief betwixt them?

This some previous owner monstrosity?

Usually when i hear of a loader and a lack of a relief problem I think "chinese". The have a fondness for plumbing quick connects right after the pump with no provision for relief.. i secretly think they just like selling new hyd pumps.. cause it is a pretty' hokey engineering concept.. even if they are trying to make a bargain basement tractor and save a few yuan... I mean.. as cheap as their component parts are.. how much would one more hose and a relief valve cost???

Soundguy

So who assembled this combination of pump, loader, valve ect without providing for a safety relief/system pressure regulator? That is a good way to get someone hurt. A ruptured hose or pipe can spray a jet of oil that will penetrate clothing and skin causing very serious tissue injuries that will have difficulty healing.

I made some assumptions(properly engineered installation) when I made my earlier suggestions for checking system pressure. I am terribly sorry about that.

 

[Kernopelli]

Actually guys......I put it all together. I built my FEL myself, I found an old Freeman trip bucket loader at our local salvage yard. It had the original trip bucket, arms and subframe for a considerably larger tractor than mine. I was able to use the metal from the original sub frame and cut it all up and fabricated a frame for my tractor, I cut length off each end of the arms and cut sections out of the width, welded it all back together, installed proper pins and bushings and made the bucket. I bought all the cylinders and the control valve off Ebay. The valve was NOS from a dealer and I got it for a song. The valve came with all the plumbing and quick connects for a Ford/NH ,1220 tractor. I got into the valve after discussing it earlier in this thread and couldn't find a relief cartridge so I contacted the seller and he supplied my with schematics for all the Ford valves and explained :
""All of the Ford (New Holland) 20-series tractors used the same valve, except the 1220 valve relief port
had a plug installed. They started with Zexel and switched to Kayaba in
later production, but basic function is identical. I don't think that these
valves share any internal components. The 1220 models used full system
pressure for loader, but the 1320 and bigger had a relief valve to clip
system pressure for loader operation."""

I knew before hand that this valve was produced specifically for a 1220 and although I own a Mitsubishi tractor ( grey model CIH 254) wasn't worried about it since I assumed every valve had an internal relief valve, it never occurred to me that it was possibly otherwise. This was originally a $700 valve package from Ford and is a joystick w/ PBY and I (AS*)umed it would work with no problem. SURPRISE!

Well, My loader has turned out great, I only have about $400 whole thing ( in the loader that is.......... the $350 pump replacement kind of negates all that!), it looks pretty factory (except I haven't sandblasted and painted it yet-that's a winter project) and is way more sturdy than my needs require, hence even more need for a relief system.

I am going to get a 3 port relief and go that route. I already had a Baum Hydraulics catalogue and forgot there were plumbing diagrams in it, so maybe even I can figure it out now . I'll get the valve from one of the other suppliers though- Baum seems to sell most everything at a high premium but they do have things you can't find just anywhere.

I appreciate all the help and now I will sleep better knowing we have saved some other poor soul the heart ache of buying an antiquated Ford NH 1220 valve and putting it on their cobbled up loader ( like anyone else would ever have this problem).
Thanks to all,

Darryl

 

[MikesTractor]

Darryl,

I have used a separate relief on several different jobs. The one that I usually use comes from Northern Tool. Northern has 2 different sizes. The valves are basically the same. The only difference is port size. One is 3/4" and the other is 1/2". Both are fully adjustable

They are simple to plumb in. As you suggested, you put it in the pressure line between your pump and valve. The third port is routed back to the hydraulic tank in some way. If your return line goes directly back to the tank, then you can tee into this line.

Here is the link for these relief valves.

Nothern Tool

Maybe this will help.

Mike

 

[Soundguy]

Darryl.. as you found out.. not all ford valves have reliefs. I have 2 ford valves at home that rely on the relief built into the tractor hyd lift cover.. thus there is no integral relief valves built into the spool body.

Soundguy