HD6G Weak 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=209715
Printed Date: 16 Sep 2026 at 1:00pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: HD6G Weak Hydraulics
Posted By: Paul-HD6G Start-up
Subject: HD6G Weak Hydraulics
Date Posted: 14 Jan 2026 at 7:12pm
I have an HD6G that I'm working harder than its had to work for the last 20 or more years clearing fence rows. We've had this machine for about the last 50 years so I do have a little history with it. The machine sat idle for about 15 years up until about 4 years ago. But I was able to get it started after new batteries and refreshing the fuel. Over the last 4 years I've used it for some small short term projects with no noticeable issues. However, I started using it to push over some trees while clearing an old fence tree line. The longer I use it the weaker the hydraulics become. Can anyone point me in the right direction? I have not been able to locate a new hydraulic filter. I don't have a book on the loader part of the machine so any information would definitely be helpful. Recommended fluid? Filter part number? Any other suggestions..... Thanks for the help
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Replies:
Posted By: Codger
Date Posted: 15 Jan 2026 at 6:25am
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There are a couple of things that come to mind that are very basic in nature. First is fluid parts wear that exacerbates as the fluid/hydraulics warm. Usually you can discern this by the engine needing higher revolutions to accomplish the same repetitive tasks as the system warms. The second is pressure relieving at too low of pressure. One would normally see this hot, or cold. You would need to tap into the system and check/adjust system relief pressure as a starting point. If you cannot surmount system relief pressure by adjustment(s), most likely the main hydraulic pump needs rebuilt, or replaced. ------------- That's All Folks! |
Posted By: Paul-HD6G Start-up
Date Posted: 15 Jan 2026 at 8:22pm
| Thanks for the input |
Posted By: DiyDave
Date Posted: 15 Jan 2026 at 8:46pm
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Might also be suction leak or plugged strainer, if so equipped... ------------- Source: Babylon Bee. Sponsored by BRAWNDO, its got what you need! |
Posted By: Paul-HD6G Start-up
Date Posted: 21 Jan 2026 at 7:24pm
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The weather warmed up a bit today (30 degrees) so I started the HD6G. The hydraulics worked normally even at low RPM. Still no leaking noted. I didn't use it to do any work today but I do have a couple of other questions. The current hydraulic filter is a WIX CW-523-MP. I contacted WIX only to find that that filter was discontinued and obsoleted many years ago. They told me that that filter had never been sold as an individual unit and was always sold as an Allis-Chalmers Hydraulic Kit that contained (1) CW-522-MP and (1) CW-523-MP filter. I'm looking for help in finding a suitable filter replacement. Thanks for the help
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Posted By: DMiller
Date Posted: 22 Jan 2026 at 6:37am
| Check Applications Associates for Cross to Baldwin as is where I got the kit for my 7G. |
Posted By: Codger
Date Posted: 23 Jan 2026 at 4:24pm
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Obsolete in Baldwin but site does give sizes to match up: https://ph.baldwinfilters.com/baldwin/en/product/baldwin-hydraulic-filter-elements/pt181-kit-baldwin?cm_re=Search-_-Flyout-_-Part&se=PT181%20KIT&sr=1" rel="nofollow - https://ph.baldwinfilters.com/baldwin/en/product/baldwin-hydraulic-filter-elements/pt181-kit-baldwin?cm_re=Search-_-Flyout-_-Part&se=PT181%20KIT&sr=1 ------------- That's All Folks! |
Posted By: Paul-HD6G Start-up
Date Posted: 28 Jan 2026 at 8:04am
| Thanks for the recent info. Very useful. |
Posted By: Paul-HD6G Start-up
Date Posted: 22 Jul 2026 at 8:27pm
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I have finally gotten back to work on this HD6G and still not having much luck. My gut tells me its a problem with the hydraulic pump. Here's what I've done: 1) Drained the old hydraulic fluid and replaced with new. While draining I found a lot of dirt in the tank. The Suction screen was completely plugged with stuff. 2) I have not been able to find replacement filters from anyone I've tried' 3) I cleaned out all of the dirt out of the tank prior to refilling. The hydraulics is still sluggish when bucket is empty particularly after it gets about 1/2 way up. With the bucket full (with dirt) it does not want to lift it. I do not hear any unusually noise or sounds when operating. At idle it will only lift the empty bucket about 1/2 way. I have to increase the RPM to get a full lift. I'm thinking I probably damaged the pump by using it with the plugged suction filter. Any Suggestions on next steps? I this Hydro pump still repairable? Thanks for any and all help and suggestions. |
Posted By: gemdozer
Date Posted: 23 Jul 2026 at 9:15am
| The hydrolic oil filter kit is 3019695 from my parts manual and it could be the pump but you could recheck the oil streaner condition maybe it could still have metal in lines . |
Posted By: 8070nc
Date Posted: 23 Jul 2026 at 9:27am
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Does it have a oil cooler and is it clean. The cooler you can keep the oil the longer you can run it before it gets slow ------------- 1984 80780 1957 D14 DES 300 with 25000 engine 616 tractor |
Posted By: gemdozer
Date Posted: 23 Jul 2026 at 5:08pm
| The oil hydrolic kit used 2 filter 1 for oil and 1 air filter breather and and a friend had the same probleme and he change the pump and he had the same probleme and finally it was a inside hose probleme |
Posted By: Paul-HD6G Start-up
Date Posted: 23 Jul 2026 at 5:22pm
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The system does not have a cooler that I see for the hydraulics I have tried sourcing the filters through Wix (#CW-522 MP and CW-523 MP), Baldwin (#181 Kit) and Application Associates, none have been any helping locating the replacement filters. Can ... you be more descriptive on the hose issue that your friend had? thanks
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Posted By: gemdozer
Date Posted: 23 Jul 2026 at 8:14pm
| My friend is died a couple years and you could check oil filter DONALDSON P164270,BALDWIN PT8395,CARQUEST 85500 or you could GOOGLE 3019695 THEY HAVE MORE NUMBER |
Posted By: Les Kerf
Date Posted: 24 Jul 2026 at 9:36am
Maybe a suction hose collapsing?
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Paul-HD6G Start-up wrote:Posted By: Paul-HD6G Start-up
Date Posted: 24 Jul 2026 at 10:16am
| Possible... maybe the hose collapsed when the screen was plugged in the suction line. I'll have to figure out how to get access to it. I think its pretty buried ... |
Posted By: Les Kerf
Date Posted: 25 Jul 2026 at 2:07pm
If it's anything like an HD5G it is definitely a tight fit to gain access  Best wishes on your endeavors
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Posted By: dadsdozerhd5b
Date Posted: 28 Jul 2026 at 6:21pm
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Should be a hose from tank to metal pipe that runs up along the right side of the machine to another hose that connects it to the pump. Check the pressure at the dump/lift valve that is where the relief valve spring is. It is adjustable. If you can’t get enough pressure for that adjustment then the side plates of the hydraulic pump are probably worn and in need of a rebuild. I think the hd5 and 6 has the same pump. Driven off the front of the engine. I have a parts HD6G with a valve on it if you need parts, pump is gone. ------------- HD5B, HD5G, (2) FARMALL A's, CUB. DO IT RIGHT THE FIRST TIME, IGNORE THE LAUGHTER. FLANNEL IS ALWAYS IN STYLE. |
Posted By: Paul-HD6G Start-up
Date Posted: 29 Jul 2026 at 6:54am
| thanks I'll know what to look for |