Construction and other equipment - Allis Chalmers HD 21 Dozer torque converter proble

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Allis Chalmers HD 21 Dozer torque converter proble

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=207495
Printed Date: 25 Jul 2025 at 9:00am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: Allis Chalmers HD 21 Dozer torque converter proble

Posted By: Shaun
Subject: Allis Chalmers HD 21 Dozer torque converter proble
Date Posted: 17 Jul 2025 at 5:56pm

I have an early 50s Allis Chalmers HD 21 Dozer with a torque converter issue. The torque converter is the old style which uses diesel for its fluid. The Dozer was working good until parked for several years runs great now but has no push power at all barely moves back and forth under its own weight. I have changed the fuel filters and I know the fuel in the tank is good and clean. If anybody has any ideas of where I can start I would really appreciate it I have looked on the Forum for other postings I am having trouble finding the mentioned restrictor to make the fuel pressure in the torque converter stay above 30 PSI I do not have a fuel pressure gauge if I can share some pictures with someone who can maybe give me a hand locating what I'm looking for I would really appreciate it. Thanks.

Replies:

Posted By: gemdozer
Date Posted: 17 Jul 2025 at 7:36pm

I am not sure but when these machine ben long time park the fuel tank have to be 75% full for good working. AM NOT A EXPERT

Posted By: Shaun
Date Posted: 17 Jul 2025 at 8:14pm

Thank you very much I will try throwing a few more Jerry cans in it and see what happens if it makes a difference

Posted By: Shaun
Date Posted: 18 Jul 2025 at 10:56pm

Hey guys I tried more diesel and didn't make any difference. When I used to operate the tractor I could be crawling along pushing a load and lift the blade at the end of a hard push while still moving no problem. Now it doesn't barely want to crawl and the blade only lifts when clutch is engaged but not in gear. I should also tell you that it is an old cable lift blade using the rear winch. Any help would be much appreciated