1020 Inj Pump no output

[john dudgeon]

I have been restoring a 1971 1020 with the major problem being a leaking main hydraulic pump. This is a project tractor I had it apart for a couple years. After reassembling and attempting to start, I am getting no fuel from the JDB pump to the injectors. I removed the line at the pump from the filter, and cycled the primer lever and have a strong stream of diesel to the inj. pump. I removed the bleed screw and the line from the top of the pump returning to the tank to allow air to escape. The wire from ignition to the terminal on the pump is attached and I can hear a definite click which sounds like the valve is opening when I turn on the ignition. I cracked the lines at the injectors and turned the engine over several minutes but no fuel came out. I replaced the injectors during repairs but did not do anything to the pump which was working fine when I shut it down. I would surely appreciate any suggestions for getting this pump working.

 

[Tx Jim]

Loosen the 2 timing widow screws on inj pump and see if fuel comes out of window area & injector lines while turning engine over??

 

[Anonymous-0]

I have been seeing this same problem more and more in the last few years. The new ultra low sulfur diesel and biodiesel are causing the plungers to stick insde the pump.. The roosas and cav DPA pumps seem to have more problems than the others. If a tractor sets without running much over 6 months this starts to happen. You will need to get the pump torn down and the plungers freed up. I can tell you I have fixed this same problem at least 30 times in the last couple of years. I can help you with this pump if you are interested. 231/757/0064 Al Baker

 

[Dieseltech]

X 2 what AL said. My MF 165 has been sitting inside to have the three point repaired just over 6 months. Was slow to start last night as metering valve was stuck in off position. It finally moved enough to start. Any water in fuel will cause valves and plungers to stick, especially if not run for awhile. Have repaired a lot of rotary pumps lately with this trouble.

 

[JDemaris]

If the plungers are stuck in the pump (which I doubt) - you don't have to pull it part to free them necessarily. Unhook one of the injector lines from pump - easiest is to unhook #1. Then line up the timing marks in the pump. Then hook an air-line to that pump port and shoot some 100-150 PSI air in there. It will push the plungers all the way out. Then when you rotate the pump, the cam-ring pushes them back in.

Main thing is to check as follows:

#1 - make sure the pump is actually turning. Take off the timing window, crank engine over and make sure half of what you see in the windowh-hole is rotating. If not the pump's "shear-shaft" is broken.

#2 - if turning - take off the top of the pump via the three little 10/32" screws. Make sure the metering valve is free and you can push it back and forth with your finger. The electric solenoid does NOT push it into "run" position. When the solenoid is "ON", all it does it get out of the way and a light spring pulls the metering valve into "RUN." If can easily get stuck and often just push with your finger will free it.

#3 If the pump is turning and metering valve in "RUN." Then use compresses air to make sure the high pressure pump plungers aren't stuck.

#4. When checking the fuel pump - do so with the engine cranking and NOT with the hand primer. Pumps can wear so they work fine with the hand primer and not at all with the engine cranking.

 

[Mike M]

First thing I'd do is to MAKE SURE the voltage stays at that shut off wire while you are cranking it !

Had a 5105 give me FITS just because I'd loose voltage there while cranking. I'd tested it as one of the first steps,but only with the key on and not as I tried to crank it to bleed it.
Boy did I feel dumb when I finally figured out the voltage disappeared after cranking a bit.

 

[john dudgeon]

Thanks for all the great suggestions. I restored a 1935 B a few years ago and found lots of help just from the archives.
This evening I'll check to be sure I'm getting voltage to the pump while starting. If so, I"ll recheck the fuel flow to the pump and, if needed, try to free up the plungers. I"ll let you know how it works out. Thanks again. John

 

[Bob]

Demaris wrote... "If the plungers are stuck in the pump (which I doubt) - you don"t have to pull it part to free them necessarily. Unhook one of the injector lines from pump - easiest is to unhook #1. Then line up the timing marks in the pump. Then hook an air-line to that pump port and shoot some 100-150 PSI air in there. It will push the plungers all the way out. Then when you rotate the pump, the cam-ring pushes them back in."

QUESTION... HOW does the air flow BACKWARDS through the delivery valve, essentially a heavily spring-loaded one-way check valve that blocks the path between the delivery (injector line) port and plungers?????

<img src = "http://i167.photobucket.com/albums/u125/27Grainfield/Deere/demaris_zpscb8f2765.jpg">

AIN"T gonna happen by blowing back through an injector port (even IF the "rotor" is indexed to that port) without removing the delivery valve.

Air blown into the CHARGING passage, with the rotor indexed to a "charging" position WOULD get to the plungers, and force them outward.

 

[Tx Jim]

Bob
I'm betting if John states it can be done(accomplished) to an injection pump IT CAN BE DONE. How many odds are you giving on a bet since you think he's wrong 10 or 20 to 1?

 

[Dieseltech]

JD has it right, air will bring plungers out when discharge port has air applied, not quickly, but the will come out if not stuck. Stanadyne service bulletin 177 explains how it should be done. Have been seeing more stuck valves and plungers lately, last 4020 JDB had to use a brass drift to get plungers out for cleaning. Only sat 4 months after previous repair, with biodiesel. Told the owner he needs to use it more with that fuel, or he will have trouble again.

 

[Bob]

So, HOW does the air get backwards past the delivery valve???

We KNOW air applied to the CHARGING passage will force the plungers outward, but he is saying to apply it at one of the INJECTOR ports(#1), and, with an intact delivery valve, flow in that direction is COMPLETELY blocked.

That is how sharp cutoff is accomplished at the end of the injection cycle... the delivery valve closes. The manual even states "some residual (fuel) pressure is trapped in the injection lines. So, if the last of the pressurized fuel (below the injector "pop" pressure) cannot get backwards past the delivery valve, HOW can shop air?

I just dug out a tech manual, and what I have posted about the operation of the delivery valve is clearly spelled out.

Does anybody have the details of "air timing" the pump at hand.. It's been a while since I've dealt with that, but in that procedure, air IS used to force the plungers outward... IIRC, there's a special Stanadyne "jig" involved, but where is the air injected in THAT procedure?

 

[Dieseltech]

Pumps that are air timed use the #1 outlet, with 60-100 PSI per the service letter.. "Note; It may take several minutes for air pressure to push plungers apart due to the sealing action of the delivery valve". Air will get past the valve, just not quickly. The valve does not seal off the outlet like Bosch or Simms pumps do.

 

[JDemaris]

Not something I ever concerned myself about (that is, how or why?). It just does. Air-timing is a commonly used technique on Stanadyne/Roosamaster pumps. A full description is given in the Allis Chalmers HD4 and Ford 4000 manuals. The purpose is not to "unstick" the plungers. It's to blow the plungers all the way out until they contact the cam-ring when the discharge injector port and head-port are aligned (for timing purposes). I've done it many, many times. Hook an air-line to the discharge port -and when the holes line up - wham. The plungers slam all the way out. A good way to static time a pump when the timing marks are missing.

 

[JDemaris]

I wonder if some of these stuck plungers are caused by anyone using heating oil instead of off-road diesel? Here in central NY, heating oil and off-road diesel come from the same bulk tank. But - when it's sold as off-road diesel a lube additive is put in. No additive if sold as heating oil.

I use two-stroke-oil as an additive in all my diesel fuel - car, trucks and tractors. I don't trust the newer fuel has enough lube for rotary pumps and it's a cheap investment.

 

[nlastovi]

From this study -

http://www.dieselplace.com/forum/76-gm-trucks/64-maintenance-fluids/177728-lubricity-additive-study-results.html

it would appear as though if 'lubrication' were to be something that someone was most worried about, 2% REG SoyPower biodiesel is by a very wide margin the thing to do.

 

[nlastovi]

another reasonably good technical reference:

http://www.infineum.com/Documents/Fuels%20Technical%20Papers/SAE/2009-01-0848.pdf

 

[john dudgeon]

jdemaris, I did # 4 on your list first to be sure I was getting fuel and while cranking the engine, I get what I consider to be a pretty week supply at the line going into the JDB pump. I reattached the line, removed the timing window cover and cranked it over and nothing much came out. Should it? I think I have a bad transfer pump. Neither the rebuildable or sealed pump (like I currently have)are available from Deere so I'll try at NAPA. If this doesn't solve the problem, I'll try unsticking the plungers with air pressure as you described. Meanwhile, I removed the top of the pump and checked both the solenoid operation and the metering valve. Both appear to be working correctly.

 

[Bob]

You still haven't explained HOW the air gets from the discharge port BACKWARDS PAST the closed one-way delivery valve and forces the plungers outward.

SOMETHING is missing here... perhaps removing the delivery valve???

 

[Tx Jim]

(quoted from post at 20:42:15 10/30/13) jdemaris, I did # 4 on your list first to be sure I was getting fuel and I think I have a bad transfer pump. Neither the rebuildable or sealed pump (like I currently have)are available from Deere so I'll try at NAPA. .

JD dealer parts personnel that told you diesel fuel transfer pump was unavailable from JD needs to attend a parts training school.
parts key #5 AR52159 FUEL PUMP 1 (DIESEL) (SUB RE42211 AND R97350)

1st is JD PN 7 2nd PN is A&amp;I

RE42211 Fuel Pump ADD 53.57 USD
A-RE27667 Fuel Pump 41.27 USD

 

[JDemaris]

One slight problem with some of the Deere fuel
pumps if the machine is a 3 cylinder like a 1020
or 300. Deere often sells Airtex pumps to replace
the original AC pumps. The same Airtex pumps are
sold at NAPA. They have a piece that sticks way
out and hits the starter if it's been replaced
with a gear-reduction type instead of the direct-
drive Delco. I had to get a farm-tractor type
Sofabex pump made in France to fit my 300B. The
pressed-together tin-can Airtex from Deere would
not fit. On four cylinder engines, it's not a
problem since the fuel pump is further from the
starter.