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

Shop Now

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

Attention Forum Users: On the 28th of December 2023 at 9:00am Central Time, we will be taking the forums down for maintenance while we prepare the new forums for your use. Please click here for more information.

John Deere Tractors Discussion Forum
:

gages

Welcome Guest, Log in or Register
Author 
Chuck in Ks.

12-06-2003 06:59:19




Report to Moderator

I was curious to see if anyone was bleeding air from the oil pressure line to the gage or not? The dealers in my area say just hook the line up.
One says it will bleed itself and the other says the air won't matter.
Does anyone have an opinion on whether direct reading gages on 2 cyl. tractors should be bleed or not?
Chuck
720D




[Log in to Reply]   [No Email]
Jake

12-06-2003 09:47:30




Report to Moderator
 Re: gages in reply to Chuck in Ks., 12-06-2003 06:59:19  
The air will not matter.
Interesting side note.... I had a gauge on my car with the plastic line for several years. One day the needle on the gauge started to flutter rapidly in a blur and the gauge made noise. It really had me baffled. Finally I figured out the plastic line no longer had any air in it. It was completely full of oil so the pressure pulses from the pump were going directly to the gauge. I disconnected and drained the line. After that all was normal with the air in the line dampening the pressure pulses from the oil pump.

[Log in to Reply]  [No Email]
Britt Misker

12-06-2003 08:56:35




Report to Moderator
 Re: gages in reply to Chuck in Ks., 12-06-2003 06:59:19  
I agree with all the above posts. The oil line on tractors is short enough that any air won't make any noticeable difference. However, on very long gage lines, shch as on a combine, (or in my case twin engine aircraft.) A 1/8th inch or 1/4 inch line with air in it will positively cause a pronounced delay in reading on a cold day. I tend to get extremely nervous when starting a pair of $80,000+ aircraft engines and wait for 30+ seconds for the gage needles to move. I have found that air is the biggest culprit for this delay, followed by cold oil. The combination of both of these has caused me to shut down the affected engines & look for EXPEN$IVE problems. Only to find out that it was a combination of air and 50 weight oil and 28 degrees. I have gone as far as teeing in a gage at the engine and watching it reach operating pressure almost immediately and the panel mounted gage requiring almost a minute to catch up and read the same. I attribute this to several air bubbles and thick oil in the lines. The thick oil causes resistance to flow and delays the equalization of pressure in the gage system.
To cure this problem, I have used jet fuel (kerosene) to purge the lines and make sure that all the air is bled out. The engine oil will slowly mix with the jet fuel over time, but will usually not travel much past the firewall.
Once that the lines have been filled with jet fuel, there will usually not be any more problems until the line is openend again. This problem usually shows up in cold weather, or when a oil pressure line has been left open for an extended period of time, such as at an engine change. If you are nervous about using keroosene, substitute 10 weight oil.
One other thing to keep in mind:
Aircraft oil pressure fittings at the engine have a small orifice inserted to restrict the flow of oil if a line should break while flying. I gives the pilot a little more time to discover the problem and (hopefully) land before the engine locks up. I suppose that this orifice contribtes to the delay experienced as mentioned above. But when the lines are properly bled and filled with a light oil, the existance of the orifice is not noticed. I install an orifice in all my ground bound equipment. If I have an oil line break on my 620 or 730, I will notice the problem before the engine runs dry.

Sorry for the long post. I tend to get carried away when describing things.

Britt

[Log in to Reply]  [No Email]
Ralph

12-06-2003 19:16:06




Report to Moderator
 Re: Re: gages in reply to Britt Misker, 12-06-2003 08:56:35  
Good discussion Britt. I think you covered it.



[Log in to Reply]  [No Email]
Clooney

12-06-2003 08:10:17




Report to Moderator
 Re: gages in reply to Chuck in Ks., 12-06-2003 06:59:19  
Chuck, I can't see where bleeding that oil line would make any difference. The oil line has such a small internal volume & even if the line is bled the bellows in the gage would still be full of air [that has a big volume].. Pressure is pressure even if it's air so other than slightly changing the response time on the gage needle bleeding wouldn't be worth the time..

[email protected]



[Log in to Reply]  [No Email]
John T

12-06-2003 07:44:10




Report to Moderator
 Re: gages in reply to Chuck in Ks., 12-06-2003 06:59:19  
Chuck, if Im hooking up a new one, I leave it cracked to bleed air out just for the sake of it, but have seen them not bled off (especially some after market ones with plastic lines where you can see the air space voids) and it never seemed to make much "noticeable" difference with the air bubbles there. With only 10 to 30 PSI or so theres not all that much air bubble compression and theres still pressure against the gauge to make it read. If your like me, its one of those thigns you just have to do lol, even if it dont matter.

Good luck n God Bless

John T

[Log in to Reply]  [No Email]
old

12-06-2003 07:18:17




Report to Moderator
 Re: gages in reply to Chuck in Ks., 12-06-2003 06:59:19  
I've never bleed oil preassure lines and also it the tractor sits for a few days the line will have air back in it anyways. The air that is in the line will compress up to what ever the preassure is in the system and still give you a good reading .



[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