A Quick Question about fuel flow in the Hydraulic head

Helping out a fellow Steelsoldier I have run into an odd situation. Form my search on the operation of the IP hydraulic head I have found alot of info. But I still have a Question, We have good fuel to the head, good fuel out of the head and the plunger is free and moving. There is no fuel from the injector line at all. I removed the fuel metering plug on the side and no fuel there either. When we removed the return check there was some junk in it, not alot kind of loked like weed stems about the size of a Mosquito needle. Could the head be plugged? What gives? What have I overlooked?

Have you pulled the side off the IP to make sure the fuel shut-off rod retracts? Sometimes when you push in the fuel cutoff rod, the plunger inside the cover sticks. Its on the side of the IP that has 2 screws holding the cover on. Once you get the cover off, there should be a small swing arm. That arm needs to move freely. You should be able to push it "backward" toward the cab and when you let go, it should snap back to the "forward" position.

I did check that ,it moves freely. how far forward does it move? I would say the lever was straight up and down when i let it go.seemed to move 1/2-3/4"back.

Ehh, its been a while since I had to tinker with one. I'm thinking mine went from the 7 o'clock position to the 5 o'clock position? I can check tomorrow if needed. Is this a truck that was running and you did something, now it doesn't or is it "I know nothing about it" just trying to get it to start?

I was told by the owner , that the guy he bought it from said it ran.(when parked)

derby said:

the guy he bought it from said it ran.(when parked)

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Heard that before.

You crack one of the injector lines at the head?

Yes, cracked one at the head and two at the injector.

Check fuel pressure at secondary filters I can't remeber exact numbers but it should be up around 60psi. It's in the pump TM
Jim

You said the plunger goes up and down. When you checked, did fuel come out of there? I ask cause one that I checked, had fuel come out after a couple cranks. I hate to say it, might be time to pull the HH.

Mine was doing the same thing. I took the center plug out (top center of hh) spun over and getting fuel there but not out of lines. So I disconnected fuel pump (electric) and had someone spin over while I watched. My plunger was spinning and going up and down, but was only going up a little past the inlet where fuel comes in to plunger cavity, so I lined up the marks on gears on hyd. head and removed head. The plunger has a little button with a snap on retainer that is supposed to hold the button on to the bottom of the plunger and mine was lying down in the injector pump undamaged, I snapped it back on and put hyd. head back on and everything back together bled the lines and she fired up and has been running great every since. Mine also had sat a while before I got it and the only thing I can figure happened is the plunger was in the up position when parked and the plunger was stuck and when the cam went down the engine oil on the button and lifter caused a suction and pulled button and retainer off. Anyway it works now. Not sure if this is your problem but you might want to check. Sorry I didn't have a camera at the time.

There was alot of fuel coming out of the center plug, alot more than I thought there would be. as soon as the in tank pump came on. I will get with the owner and see about popping the head off. The truck did set for awhile.

That is how mine was doing plenty of fuel when pump was turned on, but the plunger wasn't going up enough to push the fuel out and back down to the distribution passages and to the lines. Good luck. I'll keep a check to see what you find.

send it to me

I too am having HH issues... First off, I haul heavy equipment, so Im gone for 6weeks at a time. My A2 w/w hardtop has a leak there at the 12pt screw coming out of the HH. Im thinkin that thats whats killin the prime to my cylinders (fuel out = air gettin in)...

Ive thought bout putting a new HH on there, BUT the previous owner said it had a new IP when he bought it...Soooooo, its either I put a new IP with NEW HH on it, or I just take it to Memphis Equip and have them figure it out. Id rather figure it out myself because I want to be able to work on it on my own, as I have done with my previous trucks (Plus its cheaper than Memphis Equip)

ANY help with the HH or anybody know of sources for the HH or IP will be MUCH APPRECIATED...

OverSizeHeavyHauler said:

I too am having HH issues... First off, I haul heavy equipment, so Im gone for 6weeks at a time. My A2 w/w hardtop has a leak there at the 12pt screw coming out of the HH. Im thinkin that thats whats killin the prime to my cylinders (fuel out = air gettin in)...

Ive thought bout putting a new HH on there, BUT the previous owner said it had a new IP when he bought it...Soooooo, its either I put a new IP with NEW HH on it, or I just take it to Memphis Equip and have them figure it out. Id rather figure it out myself because I want to be able to work on it on my own, as I have done with my previous trucks (Plus its cheaper than Memphis Equip)

ANY help with the HH or anybody know of sources for the HH or IP will be MUCH APPRECIATED...

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Not doubting but you shure it's the plug. The heads are knowen to run a crack at the number three line and it puts it on the head. I use the air chuck and with it running look and find.

NO new AMBAC not even a reman pump from AMBAC............ no such thing ........... yes you can order a china made head and rotor. First loosen the delivery port bolt and retorque to 50 to 55 ft pounds...your discharge fittings should be 25 ft lb MAX... delivery valve screw is also 50 to 55 ft lb it is located on the side of the head and rotor assy. Donot try to just tighten the pieces.. loosen and retorque them..

Do they all have the electric pump I have the same problem. I get lots of fuel out of bleeder and when I removed the plug center of hh I got fuel out there to when I spin it over. I removed the cover on the side and check the shut off it seems free. The hole under the plug center of HH when I look in I see a very small hole. I placed a small stright allen in the small hole it moves when I spin the engine but not sure if it's as much as it should. Should I remove the hh next and check the clip and button.
Thanks for any help.