7580/ 8550 Fuel Tank Plumbing Question
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=164078
Printed Date: 31 Jan 2025 at 6:05am
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Topic: 7580/ 8550 Fuel Tank Plumbing Question
Posted By: GM Guy
Subject: 7580/ 8550 Fuel Tank Plumbing Question
Date Posted: 03 Sep 2019 at 6:25pm
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Hey all, I have a wild hair to get Dad's 7580 (the 78 or 79 model I talked him into trading some balers for, not my 81) going for a little tillage this fall, and the major hurdle right now is sucking air in the fuel system. So, I wanted to ask: Provided I leave the air vent crossover line and big lower fuel crossover hose intact, what would be wrong with capping off the suction and return ports on the left tank, and doing all the engine's "business" off the right tank? This would minimize potential air intrusion spots. I assume they were plumbed this way from OEM to deal with steep sidehill ground? Luckily we are fairly flat, and dont plan on getting too wild with low fuel levels, so even with the left side on the downhill side I doubt I will ever have an issue running dry. Is there any other fault to my plan that I am not seeing? Any info appreciated, Thanks! ------------- Gleaner: the properly engineered and built combine. If you need parts for your Gleaner, we are parting out A's through L2's, so we may be able to help. |
Replies:
Posted By: LB0442
Date Posted: 03 Sep 2019 at 8:37pm
The pickup tubes in the tanks are a problem with these. I thought when and if I have an issue with that I would just tie into that equalization tube running on the bottom between both tanks. Tee into it and then run up to the electric lift pump. Just a thought, haven't had a problem yet. |
Posted By: darrel in ND
Date Posted: 04 Sep 2019 at 8:59pm
| On my 7580, I had the "sucking air" issue every time the tank got down to about half full. Had a friend/allis tech tell me that the draw tubes were prone to cracking, so when the fuel level got below the crack, it was sucking air. That guy just tapped into the bottom of the tank somewhere, and it worked fine after that. On my 8550, I put an electric lift pump down near the bottom of the tanks. I can't remember all of the details of how I plumbed it, but I know that the pump sucks from a Tee that feeds from each tank. really no way that it can suck air unless the tanks go 99.9% empty. Works good. darrel |