Construction and other equipment - AC 816 backhoe or person w/dual Ft. HYD pump?

Print Page | Close Window

AC 816 backhoe or person w/dual Ft. HYD 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=31346
Printed Date: 26 Jun 2025 at 5:28pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: AC 816 backhoe or person w/dual Ft. HYD pump?

Posted By: duramax-rob
Subject: AC 816 backhoe or person w/dual Ft. HYD pump?
Date Posted: 26 May 2011 at 8:36am

Does any have an A-C 816 backhoe or had one? I have a problem with my hoe before and after I rebuilt the front hydraulic pump of the hyd oil foaming in the resevior and some at the pump. The steering which also uses the hyd fluid is jerky, but the only leaks I can find are in the loader and backhoe valves. Doesn't seem to have any air leaks. It foams enough that after 10-15 minutes of high idle time the hydraulic start to get weak. Any help would be appreciated.

Thanks Rob

Replies:

Posted By: Dave A
Date Posted: 29 May 2011 at 1:47pm

not all oils are compatable. Sometimes mixing oils will cause this. Also heat will break down the fluid and cause this. or water in the fluid will cause this. Most hydraulic fluids have a anti foaming additive. with the new pump you might have better flow causeing high suction pressure. witch pulls air out of the fluid (suto cavation). Check the suction line to see if the inside has collapesed

-------------
Play the game for more than you can afford to lose... only then will you learn the game.
Winston Churchill

Posted By: duramax-rob
Date Posted: 30 May 2011 at 10:34am

Thanks for the reply. Before I rebuilt the pump there was some water in the system and I changed all the fluids with the 33 hydraulic fluid. I replaced the bad hoses and cleaned the screen to make sure that I couldn't see or imagine any leaks. Essentually the suction side is good and working properly. I'm going to fix some of the other leaks in the pressure side of the control valves on the backhoe in the mean time while I get some different thoughts on the foamong problem. Thanks duramax-rob (rob)