Hd11 injection pump leak
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Construction and other equipment
Forum Description: everything else with orange (or yellow) paint
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=151260
Printed Date: 17 Jun 2024 at 4:28pm
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Topic: Hd11 injection pump leak
Posted By: 7060
Subject: Hd11 injection pump leak
Date Posted: 13 Jun 2018 at 7:58pm
I have a leak that looks like it’s coming from the center cap in the middle of the injection lines. Can I remove the cap? My fuel pressure gauge also reads just below the green and under a load it goes down to almost nothing. That’s the only leak I find, but that shouldn’t affect the pressure at the gauge should it? Changing the filters didn’t help the pressure.  
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Replies:
Posted By: CAL(KS)
Date Posted: 14 Jun 2018 at 7:25am
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i dont have any experience with that pump but you might have a partial blockage in bottom of tank or in shutoff valve at tank affecting pressure. is the pressure a new problem or always that way? alot of these systems have a restricter fitting somewhere and they can become plugged or removed by owners. ------------- Me -C,U,UC,WC,WD45,190XT,TL-12,145T,HD6G,HD16,HD20 Dad- WD, D17D, D19D, RT100A, 7020, 7080,7580, 2-8550's, 2-S77, HD15 |
Posted By: 7060
Date Posted: 14 Jun 2018 at 8:49am
| I have a good flow when I pulled the filters off. I haven’t owned it that long, but it did run up in the green I thought and now at high idle it is right on the line between green and red which I think it says is 8psi. |
Posted By: CAL(KS)
Date Posted: 14 Jun 2018 at 8:52am
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transfer pump could be getting weak. check your owners manual and see what it says about it, probably the same thing my 16 manual says but i dont have it on me. ------------- Me -C,U,UC,WC,WD45,190XT,TL-12,145T,HD6G,HD16,HD20 Dad- WD, D17D, D19D, RT100A, 7020, 7080,7580, 2-8550's, 2-S77, HD15 |
Posted By: Ian Beale
Date Posted: 14 Jun 2018 at 4:14pm
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There is more on those PSB pumps in here http://www.oldengine.org/members/diesel/Ambac/AmbacMenu1.htm" rel="nofollow - http://www.oldengine.org/members/diesel/Ambac/AmbacMenu1.htm We had a considerable round of the kitchen with the one on our AC 45 grader but that was a while ago. IIRC there is a copper washer under that plug, which is on the high pressure side so shouldn't be affecting your gauge pressure. The primary is a gear pump so it shouldn't be physically affected by changing filters. They can leak from the shaft seal but that ought to show up in the engine oil. The seal is a standard commercial one if you need one. Depending on which version you have the return restrictor is either a valve assembly screwed into the front port return line or an elbow with a restrictor hole same place. If you get to taking the injection head off there is a screw in fitting on the side of the head that has to come out before you can remove the head. It has a square section o-ring on the end which has to come out too - and apparently it is now made of "unobtanium".
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Posted By: Ray54
Date Posted: 15 Jun 2018 at 10:47pm
| Ian you sure the ring is square. The common leak in old Cat fuel pumps from the 50's is a O-ring. But after 60 years they all look square and when a new o-ring of corret size is installed leak goes away. |
Posted By: Ian Beale
Date Posted: 16 Jun 2018 at 1:33am
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Ray IIRC it gets a mention on here back quite a way when I was battling our AC 45 pump problems. As did the "unobtanium". I gather some of the later heads didn't have that oil (IIRC) feed but I've never seen one.
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Posted By: DMiller
Date Posted: 16 Jun 2018 at 6:24am
| I have a spare inj pump for my 7G, tried to have it looked at by a few rebuilders to make a good spare, seems parts for these PSB pumps are really Unobtanium. |