Farm Equipment - 7040 losing prime

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7040 losing prime

Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=203132
Printed Date: 18 Sep 2024 at 11:30pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: 7040 losing prime

Posted By: AllisFreak MN
Subject: 7040 losing prime
Date Posted: 09 Sep 2024 at 8:10pm

My 1975 7040 just recently started losing its fuel prime if it sits for a couple weeks or more. I have to pump the primer and then it will start. It runs fine once started and if it's only a few days in between it will start fine. The primer plunger was replaced with a new one a couple of years ago. Any idea what would be causing this? Thanks.

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'49 A-C WD, '51 A-C WD, '63 A-C D17 Series III, 1968 A-C One-Seventy, '82 A-C 6060, '75 A-C 7040, A-C #3 sickle mower, 2 A-C 701 wagons, '78 Gleaner M2

Replies:

Posted By: Mattman
Date Posted: 09 Sep 2024 at 8:45pm

I had same issue. I had to change tank to pump supply hose. Didn’t leak fuel but sucked in air. Learned that on this site. Hose I removed looked good but haven’t had to prime it for 7 or 8 years since changing it. They deteriorate and let just enough air in to drain back and lose prime.

Posted By: nanuk
Date Posted: 10 Sep 2024 at 10:34am

my 7060 is with issues too

my prime plunger rubber disintegrate. I was able to source a new plunger from the "Local" (45min drive) dealer, for just under $100. They said they couldn't get the rubber separate.

now, when I prime, I can hear air coming out the pump.

I'm looking into getting the seals/gaskets for the pump and replace them.

it runs, but is rough with no load and from idle to 2/3 throttle.

once under load running PTO/RPM, it seems to run OK, with the frequent pulses....

only have one so no time to tear into it right now.

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AC7060Pd 1975