Removing, rebuilding, reinstalling Hydraulic Head

kennys@wi.rr.com

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On Saturday my Deuce died at my shop and it was suggested to me that my hydraulic head may be the problem. I spent the last few days reading threads on what to check and how to go about removing the head and I talked to Gimp about it. I will admit that at first the idea of diving into any part of the IP scared me a little bit. The price tag of a new IP or even just the head scared me more though. But I dug in and did it. I found the problem and am in the process of taking care of that problem. I noticed when reading all the threads there was great information and good diagrams, but no real world pictures. So what I did was take lots of pictures to help the next guy do this job a little easier and to help me remember how it all goes back together. I will do my best to explain what the pictures are and hope they help. Also when reading this I know there will be a few people out there that will point out why I am wrong how I did it wrong and what I should have done. That's great, why didn't you post a thread when you did it and share with us all what you learned? If there is a tip that can help please add it, if there is a reason why I'm an idiot, well add it to the list.

One thing I learned was there is a plunger inside the HH that moves up and down on a cam. This plunger can become stuck if any debry gets past your fuel filters or with the ULSD fuels that do not propperly lubricate our pumps. The first pic shows the tp of the HH. Remove the bolt/plug in the center. It's a 3/4" and may be better reached with a nonimpact socket because it's a bit tight in there. Remove the plug and be very careful not to let anything get into that hole. Might be a wise idea to spray the area with a cleaner first and then wipe it or blow it off. Now get a wooden dowl or a soft metal drift and someone to turn the motor over for you. When the motor is turning that dowl/drift should move up and down. If it does not, as mine did not, then here is your problem. Use the down/drift and hammer to lightly tap on the plunger. This may free up the plunger. Do not hit it too hard, there is a small button on the bottom of the plunger that can be easily knocked loose, this is a bad thing to have happen. After tapping if the plunger has gone down turn the motor over again and see if it is now moving. If it moves great, hope that it was a fluke and carry on. If not,as mine did not, you have more work to do.

To remove the HH it's not that hard, took me a little over an hour with taking pictures. Make sure you have some way of marking your fuel lines. I'm sure there is only one way for them to go back in as long as you don't bend them, but why waste the time trying each lines fit, just lable them and be done with it. Also remember the order they come off and reverse that order to replace them. What I found worked best for me was to do the lines to the cylinders in this order: 5,3, 6, 2, 1, 4. Again as stated earlier I'm sure someone has a better way, but this is what worked for me. There is also the over flow T in the front of the HH to come off. Those lines ar 7/16" if memory serves me correct. Then the fuel line to the back of the HH and I believe that was a 9/16". It is much easier to get to that back fuel with all the injector lines out of the way first. when you look at the second pic you will see a cover with 2 screws just below the HH. That is the cover for the fuel shut off valve. Remove this cover and it should look something like the third pic. Slide off the clip that holds the slide bar on. Then cut the wire holding the retaining screws in place and remove the screws. The whole piece will slide out now. Be careful as there is a piece on the end of that shaft that spins on a very small pin. In the last pic you can see the gear inside that housing and just above the gear in te middle of the housing is a small indicator arrow. My gear has a red and scorred tooth, your may only be scored. This is not easy to see with the fender in place. You can see it here because I was able to lower the camera in place. For you to see it you will need to crawl under the fender and look through the vent slots, and even then it's not easy. That tooth muct line up with that indicator, that's the only positiong the HH will come out in. To line that up you need to rotate the motor. Here is where you need to do what works best for you. When that is lined up remove the 4 nuts that hold the HH down. There are clips under the nuts and on top of the HH, don't lose them. Then as long as the gear is in the right position the HH should be able to be picked straight up and out.
 

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kennys@wi.rr.com

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Now that you have the HH out what are you going to do with it? Most guys I know will go ahead and spend the money to just replace it. All that I have read says these parts can not be rebuilt. Pesonally I take that as a challenge. Here is my thinking (and again there will be plenty of you out there to tell me I'm wrong and I'm wasting my time, it's my time so deal with it) I can spend $400 on a new HH or I can waste 3 hours of my time to pull it out, redo it and put it back together. I have way more time than money and if it's bad then what's the harm.

I took the HH down to my dads house, this is where we have rebuilt a few items that we were told couldn't be done. As you can see in the pic my plunger was stuck up and wasn't coming down for anything. A lot of WD40 and a few taps with a drift and the plunger moved down. lubed it up and tapped it back up to see if it would move freely, and of course not. So we decided it was best to take it apart, and yes it can come apart very easily. The plunger must be down, do not force it too far down there is a retaining plate holding it from going too far and it's the same plate that rotates it with the gear. When the plunger is down collapse the spring and remove the 2 spring retainers. These are no different than if you were looking at the top of a valve. When those come out off comes the spring and the bottom plate. Now you can see the gear and the plunger retaining plate I was talking about. Tap the plunger up and use a drift to move it the rest of the way up if needed. The button fell off the bottom of mine and forced the plunger too far up on mine sticking it in place, that caused it to not be able to spin and therefore cracking the retaining plate into 2 pieces. You would also brake the retaining plate if you pushed the plunger too far down. Now you should have the Head, plunger, coild spring, bottom spring plate, top spring plate, 2 spring retainers, button, 3 finger spring that holds the button in place and the fuel shut off plate.

We looked at all these parts for a few minutes and I thought for sure I was going to need a new HH because of the cracked plate. However, thank to Gimp, I now have that retaining plate on the way. I was also still dealing with the fact that my plunger would not move freely in the head. Well my dad being the old Air Force mechanic and shade tree mechanic that he is pulls out a tube of lapping compound and we got to work. Using a small dab of compound and a drill we relapped the plunger into the head. If this is something you decide to do, make sure you change directions of the drill freaquently and move it up and down, do not stay in one place for any length of time. Just did it enough so the plunger is snug but movable. That plunger needs to be able to move up and down as well as spin in the head, so snug is good loose is bad. Also make sure to spray cleaner into all the journals of the plunger and the head to get any debry out of them. And when spraying into an injector port note that it will come out of the port 180* from it and it does not taste very good. When all done and all clean use some fresh oil to lube the plunger and pu it all back together. Best of luck that it will now work for you. I have to wait until I get the retaining plate from Gimp to put mine all back together and try it. If you look at the included pics on this post you can see all the parts that we removed as well as the broken retaining plate. If anyone has a "bad" HH they would be willing to send me, next I'd like to remove the set screws from one and see what's inside of it. Or maybe you want to know if this will help fix yours but just aren't able to try it, maybe I can help.

I can't tell you for sure yet that this is going to work, but I see no reason why it won't. Either way I will be sure to post more pics and results of my testing when I get the part in and get it all back together.

O-Ring Sizes:

Large O-Ring: 2.484 x .139 = -230 or 230 (depending on which standard)
Small O-ring: 2.109 x .139 = -227 or 227 (depending on which standard)
Actuator O-Ring: .426 x .070 = -013 or 013 (depending on which standard)
 

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gimpyrobb

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Also, when taking things apart, make sure you see which way it goes. Neither Kenny or I noticed which way the fuel shut-off block goes in the head. One side of that block has a dimple in it. We don't know if it is supposed to face up or down. :roll:
 

doghead

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Kenny, once your HH is reinstalled, I would suggest you leave the shut off cable cover off and turn on your in-tank fuel pump. You need to watch for leakage of fuel around the shaft you lapped(to free it up). That lapped assembly is "fuel tight", if it leaks after lapping it, you will get fuel in the engine oil. Just be sure to check that.

Of course, if the O-rings leak, you could see fuel because of that also.
O-ring sizes have been posted. I would use new o-rings.

Great pics and write-up.
 
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Nice write-up this far, Kenny.
Like you stated, it's only gonna cost some time and a few bucks to try. I hope it works well, if not, the education will be worth the time.
I.P.'s have a bad reputation for being "replace/rebuild" only, I hope you can prove them wrong.
 

kennys@wi.rr.com

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Well it was without question a learning experiance. However, I am sad to report that the HH leaks real bad through the fuel shut off. I will go back to the shop later today and see if there is anything else I can try, but at the moment I am out of ideas. So if anyone has a good/mostly good HH laying around I could use one.
 

kennys@wi.rr.com

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I have an UPDATE. I talked with Gimp on the phone and believe it or not, I may have forgotten something. The shaft that actuates the fuel shut of has a small O ring on it. That shaft and O ring need to be in place before testing for leaks. I put that in and I am happy to report there is no more leak. Later I will get the injector lines back on and see if she will run.
 

treeguy

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What is this HH you all speak of, is it that infamous bow tie/drive washer that I had split in my MEP-002? It looks like yours has split from a stuck (non rotating shaft) and the gearing forces the bow tie to spin so it shatters. I just filed a V groove into the crack and welded it together and filed it smooth....VOLLA! IMHO, real gutts to tackle the deuce IP, nice article, good luck!
 

JDToumanian

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"HH" is the injector pump's "hydraulic head".... the round part on top that the injection lines come off of.

The shaft that actuates the fuel shut of has a small O ring on it. That shaft and O ring need to be in place before testing for leaks. I put that in and I am happy to report there is no more leak.
I suspected that was the problem too... Glad to hear it's so-far-so-good.

Jon
 

kennys@wi.rr.com

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Well I put it all back together. Then I went to try it and...... nothing. Then I let the batts. charge a bit more and hit it with a shot of ether. She fired right up. She runs great and no leaks to speak of. I will have to wait for the rain to stop before I can take it out for a victory lap, but the main thing is that she runs. And of course I get bragging rights for rebuilding the HH after being told it couldn't be done.
 
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