Hd7g injector pump filter in pump?
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=140977
Printed Date: 02 Aug 2025 at 10:54pm
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Topic: Hd7g injector pump filter in pump?
Posted By: doctorcorey
Subject: Hd7g injector pump filter in pump?
Date Posted: 31 Jul 2017 at 4:53pm
| Trying to find some info on a small filter located at the base of the pump head. My service manual shows it on page 4-14, figure 18, but the parts book doesn't show it. Bosch pcb pump.I don't have a pump book for this. The service manual also makes no mention of this filter or it's effect if it gets clogged. |
Replies:
Posted By: gemdozer
Date Posted: 31 Jul 2017 at 5:42pm
| He sould't have a filter at bottom head, he has a line from fuel filter who connect to bottom pump injection head . |
Posted By: doctorcorey
Date Posted: 31 Jul 2017 at 6:07pm
| There is a hex head plug or bolt below the pump feed line going into the injector head. It would probably be there. |
Posted By: Ian Beale
Date Posted: 31 Jul 2017 at 6:44pm
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Try this http://www.oldengine.org/members/diesel/Ambac/Fuel1.htm" rel="nofollow - http://www.oldengine.org/members/diesel/Ambac/Fuel1.htm |
Posted By: doctorcorey
Date Posted: 31 Jul 2017 at 10:23pm
| Thanks, Ian, that's a pretty good article with excellent cutaway diagrams. |
Posted By: doctorcorey
Date Posted: 06 Aug 2017 at 8:18am
| I got back down home to my loader and changed the fuel filters, had a heck of a time getting this normally flawless-running machine started. I traced my problem to a sticky control sleeve in the injector pump head. With some manual manipulation of the linkage I managed to free it up and got it started. Worked perfectly again but then displayed a tendency to get sticky again. More working the linkage by hand and freed again. Next morning stuck again, freed it again and used the loader for 2 straight hours with flawless performance. I think there's still some varnish or gunk in there, hopefully with the clean fuel and a little fuel conditioner it will eventually stay free. THis problem started last year when the tractor had sat for a year or so. I started it up and it ran away full throttle. I hit the cutoff handle and it died, would not restart without a lot of cranking and cussing. Months later same thing but I finally got it started and it ran fine till last week. If I still have problems I'll remove this valve, etc. and clean/polish it. The shut-off cover removes with two screws and you can run the motor with it off and observe the operation of the valve. Once I determine if it's the little shaft and lever assy. sticking, or the actual sleeve/plunger mating surface, I'll service that area. There is a little info, mostly old, out there on this subject, but most of the people who have dealt with problem either won't share their knowledge or have passed away. Same way with the old airplane engines I deal with. I'll soon know, and I will share it. I also feel that my fuel pressure is a little higher than I recall the norm being. Maybe I just never paid much attention as it was always in the green. 30 is in the green but at the top of it. AC specifies a minimum of 8psi. Cheers from Missouri |
Posted By: Ian Beale
Date Posted: 06 Aug 2017 at 5:08pm
|
We mobilised an AC forty Five that had sat for quite a while. It would start OK then once brought back to idle would stall when you advanced the throttle. Diesel mech son eventually traced the problem to a tiny burr on the control shaft in to the control valve in the head. When it got primary fuel pressure on it was when it locked up. Took him about 8 hours to find. Might help your search. |
Posted By: doctorcorey
Date Posted: 06 Aug 2017 at 8:50pm
|
Ian Beale wrote: