Allis 5040 slow Hydraulics

[MHarryE]

Here is a quote from one of my hydraulic design texts - "When fluid returns to the reservoir, it often contains bubbles which will dissipate, if given enough time. For this reason, reservoirs should be made large enough and have enough baffles to provide this time interval. A reservoir capacity equivalent to two minutes of maximum system flow is generally considered adequate." So your system has a 6.3 gpm pump so the minimum reservoir size should be 12.6 gallons - but you probably don't have one that size. Your open center system with a gear pump is constantly circulating that 6.3 gpm, but most of the time it is going right back to tank. Air bubbles happen, and it is the reservoir's job to get rid of them before the fluid takes its next trip through the system. So I wouldn't be concerned to see bubbles in your oil.

At the start of this thread, you plugged the gauge into the outlet port and couldn't get close to relief pressure even at high idle. Now your system reaches relief, and by the hose in the bucket method your flow is correct although you didn't get to check it at full pressure. Your posthole digger is now working okay so the 3pt will lift it at low engine speed so you don't have to have it spinning fast when you pull it from the ground. Sounds like the dump wagon is working okay although you have not yet been able to run it with a full load since fixing the problem. Unless I am missing something, sounds like you have taken care of the problem.

The guy who sold you the o-rings sounds like he wants to build customer relations. One time we were running a prototype combine in Eastern Colorado and blew an o-ring on our fuel injection pump. The mechanic and I drove to the nearest town that had farm equipment dealers and first went to the Allis-Chalmers dealership. The parts guy looked it up, said he didn't have anything that would fit. We asked if he could have one air freighted out and he said we wouldn't want to pay the air freight for a 50 cent o-ring. Huh? We were down, whether it was a 50 cent o-ring or an expensive transmission. We next drove to the John Deere dealership since at that time A-C and Deere used the same fuel injection pumps. The parts man said he didn't have any in stock but he took us out in the workshop to his senior mechanic to see if he could help us out. Of course they knew we were from A-C -- by the caps and the Allis-Chalmers Engineering sign on our service truck. He pulled out his box of left over o-rings and we searched all searched until we found a couple close matches. No charge. Back to the field and running in a few minutes. We talked about it later - even though our paychecks came from A-C, if we farmed in that area it would be hard for us not to buy from Deere just because of the dealership and how they treated the customer.

 

[ametcalf]

MHarryE,
Thank you for all of your help on this project. We are very satisfied with the progress we made on making the operation of the tractor safer by improving the way the hydraulics are working. My wife and I had already decided not to try and solve the air bubble problem. Your last post justifies that decision. The tractor is like me, it is old, leaks and has taken a lot of abuse over the years. But we can both still do what we need to do. Your information on the air bubbles was very informative. The reservoir on the tractor is 19 qts. I did notice took about 2 hours for the bubbles to disipate from the bucket in which I caught my flow test. Last Wednesday I was able to use the dump wagon to dump the heaviest load I had ever had on it and it dumped great with only 1500 rpm on the tractor. I don't think we could get the system working much better thanks to all the good help given by everyone.
Your combine story brought back some good memories. In 1962, when I was 19 I drove a John Deere 95 on the wheat harvest starting in Kansas and ending in Montana. A great summer job for a Wisconsin kid who had never even seen one of those big machines before I got there. When I flew Lear Jets I remember picking up a computer board in Louisville, KY and taking it to Chicago, waiting for it to be repaired and flying it back to Louisville. I think the repair bill was something like $12.00. GE didn't hessitate to pay the $5,000+ for the trip because of what it cost them to have a whole assembly line sitting on their hands. Later in my career I flew for one of the premire overnight freight outfits and I couldn't believe some of the stuff I saw in the back. Everything from empty cardboard boxes to car tires. A lot of people don't understand the price of a product is not always related to the value of the product.
Thanks again to everyone who helped. Now on to the next project. Brush forks and a home made grapple for our BX23.

 

[MHarryE]

Nice to hear of someone who was on the harvest even before me. My first year was 1967. Gleaner insisted that all engineers get field time every season, driving and repairing. It gives a person a lot better insight when they are designing something if they have to fix it, so we at Gleaner tended to design things for easy access and serviceability. 22 years later when I moved to Case it was similar - I wrote 3 weeks in the field for all of the engineers reporting to me. After a couple years there it was on to Caterpillar for the rest of my career. A lot more difficult to talk owner with a 60 ton excavator to let you play with his machine, so eventually when I retired I got my own mini-excavator. My dad fumed about having such an expensive toy for spading a garden the first time I used the mini to get ready for planting, but what a back saver, and loads of fun.

 

[ametcalf]

......so eventually when I retired I got my own mini-excavator. My dad fumed about having such an expensive toy for spading a garden the first time I used the mini to get ready for planting, but what a back saver, and loads of fun.

Reminds me of the old joke about the man in prison whose dad wrote him lamenting the fact that due to his son's incarceration he had no one to dig up his garden. The son wrote back and said, "What ever you do, don't dig in the garden, that is where I buried the guns." Well the FBI, Sheriff, and State Police all decended on the poor old man's garden but after extensive digging found no guns. A week later the man wrote his dad and appologized for the method of getting the garden dug up but under the circumstances he said it was the best he could do. :laughing:
I saw the excavator in your signature and wondered what the story was. I have so much fun on our BX23 that I don't charge anything for the small jobs I do for friends so I get very little kidding about my expensive toy. I seem to know a lot of people who need a favor that the BX23 seems to be the right size for.

 

[J_J]

Another fellow on TBN also fixed the sluggish hyd on his tractor by finding a pin hole leak in the suction line. Bubbles in the tank/reservoir is almost a giveaway for a suction leak. Other things that can cause bubbles is cavitation, and relief valves, releasing fluid under high pressure.