Welcome! Please use the navigational links to explore our website.
PartsASAP LogoCompany Logo Auction Link (800) 853-2651

Shop Now

   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver

Crawlers, Dozers, Loaders & Backhoes Discussion Forum

310A Hydraulic Question

Welcome Guest, Log in or Register
Author 
TomNTex

02-02-2008 01:41:10




Report to Moderator

Hey Guys,

I have a 81-82' 310A and I'm trying to get a better understanding of the hydraulic system. I have the tech manual that I've been studying and now I have a quick question. I know it's ignorance on my part but bare with me please.
I understand the trans pump feeds the main pump and also feeds the clutch control valve (reverser). Testing pressure at the bottom of the reverser control valve should have at least 135 psi. With the trans filter down stream of the trans pump, what keeps the pressure relief valve from opening when it reaches 50 psi and dumping back to the sump?
I'm troubleshooting slower hydraulics once the machine warms up. I've got 155 psi at the reverser with little fluctuation going from forward to reverse while in park. So I don't think the relief valve has any trash. I only register about 3-5 psi inlet pressure though on the main pump in stand by (2200psi). Also the pump is a little noisy. I have about 60 hours on this rebuilt pump, reverser, and engine. I hope to "fine tune" the hydraulic performance myself as I've already given the dealer all I can afford on the major repairs. Anyway I know I have some issues with the steering and after reading some archives I think I will cap off the pressure to the steering and see if that improves my inlet pressure. Maybe I have a high pressure leak causing some of the problems. If not I will continue testing through the loader and backhoe controls as well as checking the priority valve adjustment.
But looking through the manual I didn't understand how the trans pressure reaches 150psi with the pressure relief valve on the filter is set at about 50psi.

Sorry for the long post and I appreciate any guidance or suggestions.
p.s. Even though the main pump pressue appears ok, could this still be a problem with the stroke control valve hence the noisy pump(slight tapping). I guess that wouldn't cause a low inlet pressure though would it?
Tom

[Log in to Reply]   [No Email]
Roy Suomi

02-03-2008 05:22:15




Report to Moderator
 Re: 310A Hydraulic Question in reply to TomNTex, 02-02-2008 01:41:10  
I went out to my barn and picked up a tech manual for this machine this morning...That 50 lbs differential pressure is a measurement obtained if you use Deere"s fancy schmancy filter test package...I use the old road mechanics test...With a gauge in the reverser control valve bottom port , tractor idling, notice pressure reading...Now , speed up the engine to wide open slowly..How much pressure difference is there from 600 to 2500 rpm?? At 40-50 lbs difference on this test , I"ll pull the filter relief valve and pull that little piece of crap out of the poppet in the spool..That poppet will seat on the roll pin when free..If it"s up from the roll pin ,it"s stuck...

[Log in to Reply]  [No Email]
Roy Suomi

02-02-2008 19:25:30




Report to Moderator
 Re: 310A Hydraulic Question in reply to TomNTex, 02-02-2008 01:41:10  
Another thing.....Noisy pumps offen can be attributed to loose splines on the pump drive..Seem to rattle louder when slightly worn..Splines may look OK by eye...



[Log in to Reply]  [No Email]
Roy Suomi

02-02-2008 14:23:57




Report to Moderator
 Re: 310A Hydraulic Question in reply to TomNTex, 02-02-2008 01:41:10  
Hi guys...Just me again...On your hydraulic pump there are 2 plugs on the starter side of the pump, on the front cover ..Top plug is stand-by pressure...Bottom plug is charge pressure..I've found that taking your readings there are going to be a bit more accurate..You will be able to see what actually is going to the pump for charge pressure..I've run into a LOT of destroking solenoids[ opposite side of test ports on front cover] that are faulty and cause reduced hydraulic pressure readings..A quick test for this is , Remove the coil from the solenoid , remove the protruding solenoid stud/valve from the pump cover..Install a "test" plug available from Deere into the port and try to start the machine..A good tight hydraulic system will drag the starter down as it's cranking..operate a function to unload the hydraulic pressure and it should start..Now take your reading..If it's better , the solenoid is faulty....

[Log in to Reply]  [No Email]
Jonathan in MA

02-02-2008 04:22:37




Report to Moderator
 Re: 310A Hydraulic Question in reply to TomNTex, 02-02-2008 01:41:10  
havent had the pleasure of working on a 310a in awhile so take it as such.. with luck, Roy will chime in soon. I've found that if the front pump isnt "chattering" that its being fed enough oil from the charge pump. Even though the charge pressure is low, its still enough to run the hydraulics. If the front pump is starving for oil it will cause a shuddering or chatter in the loader or backhoe functions. You can cap the pressure line right at the front pump and see if your stand-by pressure increases. That will tell if you have a high pressure leak downstream. Or just start it and dont operate any functions and see if the pressure lines get hot. They shouldnt with a closed center system. That "steering issue" could be dumping oil and more so when warm . As the steering gets priority, it will slow the loader down if it is leaking. See if the pressure adjusting screw (the allen screw on the bottom of the front pump) is buried into the locknut. Generally if everything is kosher, then the head of that screw protrudes out of the lock nut approx. 1/8 inch. If its below the surface of the locknut, then its adjusted too high trying to "not-by-the-book" methods, but it may help..

[Log in to Reply]  [No Email]
TomNTex

02-03-2008 22:12:28




Report to Moderator
 Re: 310A Hydraulic Question in reply to Jonathan in MA, 02-02-2008 04:22:37  
Guys,
Sorry I've been away for a couple days.

I really appreciate you willing to share your knowledge.
I'll be leaving Kuwait tomorrow night and will have a month to play around with this toy.
I stay posted as I progress through the test and results.
Thanks again I really appreciate you guys.

Tom



[Log in to Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop to:


TRACTOR PARTS TRACTOR MANUALS
We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]

Home  |  Forums


Copyright © 1997-2023 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters

Website Accessibility Policy