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question backhoe hydraulics

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=190512
Printed Date: 30 Nov 2024 at 4:53pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: question backhoe hydraulics

Posted By: LouSWPA
Subject: question backhoe hydraulics
Date Posted: 06 Sep 2022 at 10:25pm

I have a RK37 with a backhoe attachment. The inner arm up/down is real awkward. It will come up rather smooth (more or less), but going down it is real erratic. I can ease the lever forward, nothing, a little more, nothing, etc, and then all of a sudden, wham, it slams down. If I do get it to go down easy, as soon as it meets resistance, it stops. then wait, and wait, I ease the stick forward, and at some point, I and the hoe shoot up as the bucket sinks.

I admit I am a bit ham fisted, I struggle to operate any of the controls smoothly. But i do manage reasonable operation with a lot of concentration, but that one cylinder is a bear.

Any ideas?

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I am still confident of this;
I will see the goodness of the Lord in the land of the living.
Wait for the Lord;
be strong and take heart and wait for the Lord. Ps 27

Replies:

Posted By: DrAllis
Date Posted: 07 Sep 2022 at 5:56am

If possible, I would switch the hoses on that cylinder and see if the problem is the valve or not. I'm thinking the cylinder has internal issues, but test the valve first even if it means making a new hose or a jumper/splice hose.

Posted By: doctorcorey
Date Posted: 07 Sep 2022 at 8:28am

Is this a problem that just started, or has it always been like this? And, does the boom stay up with the tractor shut off, or bleed down quickly (seconds, minutes, hours)? I ask, because my Allis loader had bad packings that allowed pressure to bleed off the lift (with motor off) , and sort of hydraulic-lock the cylinder. It would take a lot of effort to move the lever/valve to get it unlocked, then would operate ok

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Semper Fi USMC 1958 HD6G, 1959 MF 203 loader, 1960 Case 420B Backhoe, MF 65 Tractor/Loader Diesel

Posted By: LouSWPA
Date Posted: 07 Sep 2022 at 10:46am

DrAllis wrote:

If possible, I would switch the hoses on that cylinder and see if the problem is the valve or not. I'm thinking the cylinder has internal issues, but test the valve first even if it means making a new hose or a jumper/splice hose. Good idea, I think I will try that, thanks

-------------
I am still confident of this;
I will see the goodness of the Lord in the land of the living.
Wait for the Lord;
be strong and take heart and wait for the Lord. Ps 27

Posted By: LouSWPA
Date Posted: 07 Sep 2022 at 11:04am

doctorcorey wrote:

Is this a problem that just started, or has it always been like this? And, does the boom stay up with the tractor shut off, or bleed down quickly (seconds, minutes, hours)? I ask, because my Allis loader had bad packings that allowed pressure to bleed off the lift (with motor off) , and sort of hydraulic-lock the cylinder. It would take a lot of effort to move the lever/valve to get it unlocked, then would operate ok

It's hard to say because, as I said, I am a bit ham fisted, although getting slowly better, and I was not the person who put the first 50 hours on it. When I first started using it, it was hard to tell if it was me or the machine. But I do think this is something that has developed over time. I have been meaning to ask the guys at the church if they had problems with it, but just haven't got the chance. I bought this new about a year and a half ago, and I loaned it to a local church right off the trailer on the way home from the dealer. The whole hoe bleeds down rather quickly. While I am using it, I occasionally need to reset the outriggers, and if I leave the boom all tucked up overnight, it's all relaxed and on the ground in the morning.

-------------
I am still confident of this;
I will see the goodness of the Lord in the land of the living.
Wait for the Lord;
be strong and take heart and wait for the Lord. Ps 27

Posted By: doctorcorey
Date Posted: 07 Sep 2022 at 12:01pm

LouSWPA wrote:

If you raise the boom, then shut off the tractor, wait a while, and then pull the boom lever to the 'up' position, and the boom drops harshly, probably a good sign of worn packings, with fluid leaking past the seal into the shaft side of the cylinder. Lucky, on a backhoe, only one to worry about.

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Semper Fi USMC 1958 HD6G, 1959 MF 203 loader, 1960 Case 420B Backhoe, MF 65 Tractor/Loader Diesel