(800) 853-2651
SHOP NOW

rebuilding oil pumps

D

David G

Well-known Member
I would think that a CNC mill would be good to rebuild oil pumps with, just mill down deeper, then mill top off.
 
Unless you can make oversized gears and mill the "gear pockets" larger to a precision fit to the gears truing up the "sides"
is only fixing part of the problem, and probably the smaller part of the problem.
 
Not necessarily. The outside edges of the pump gears don't normally touch the outside of the housing or the inner edge of the space between teeth. Also, one gear usually drives the other always pressing against the driven gear taking up the space. Unless garbage or other bits are flowing through the pump I don't see how the outer edge of the internal housing wears.
 
"I don't see how the outer edge of the internal housing wears"

Ag hydraulic pumps don't exist in a "clean" world, and I've never seen a pump with HOURS on it WITHOUT the housing worn and gouged from debris passing through the pump.

And if the bushings or bearings wear even a little the gears tear into the housing. When you replace the bushings or bearings and get the shafts back centered there's excessive clearance between the gear teeth and the housing where the gears chewed on it.
 
Most of the gear pumps that have aluminum housings and steel gears are "machined in place" for lack of a better term. The gears are pressed into a very slightly undersized center housing. When the pump is turned the gears "cut" the housing for a perfect fit.
 
Just the fluid passing through the pump will cause wear even if there is no debris in the oil. The pressurized oil will cause some side thrust on the gears. I have a Buda oil that was worn out. Their design has the idler gear's shaft pressed into the gear and turning in housing. The shaft bore and gear bore were both worn badly. I think it would be possible to mill the housing oblong and make a liner to fit, then bore the liner to fit the gears. After the gear ODs were reground to round and straight. I saved that pump just in case I ever get the chance to do it.
 
Did not want to stir something up, just thought most of the wear is on the body and plate on end of gears.

I am thinking about this because of NLA parts.
 
.....I am thinking about this because of NLA parts.
Click to expand...

I agree that a simple re-machine of the housing and end plate might be just enough to put a badly worn pump back to a usable condition. Certainly not like new but good enough to keep an old machine running.
 
That would help immensely. There would still be some loss but it will get you close enough. It's been done plenty of times.
 
(quoted from post at 21:09:13 05/05/18) Most of the gear pumps that have aluminum housings and steel gears are "machined in place" for lack of a better term. The gears are pressed into a very slightly undersized center housing. When the pump is turned the gears "cut" the housing for a perfect fit.
Click to expand...

No offense intended sir, but I don't believe that for a second.
 
If it is a gear pump.

As you should know. The oil travels between the gears and housing toward the outside and not between the gears. In order to create enough vacumm they're is nearly no clearence at all between the flat surfaces of the gears and housing.

Milling the surface where the flat part of the gears run would be no big problem. You could use plastigage to check the clearence on the top and bottom before and during the milling process. Just need to use extreme caution to not cut into the sides of the housing where the oil gets transfered between the gears and housing. Cutting into it could cause a loss in vacumm and oil pressure rendering the pump useless.

The only other thing to watch for would be a pressure refeif valve if it has one. To much cutting and it could be thrown out of whack.
 
David, I think you're right but I can't remember where I saw it.

A very interesting website on hydraulic system repair and diagnosis is here
http://www.insanehydraulics.com

Brandon
 
You must log in or register to reply here.

Similar threads

J
drill presses
2
Replies
31
Views
1K
Hdonly
Hdonly
Majorman
Crossley Engine
Replies
2
Views
241
Janicholson
Janicholson
D
Got new mil
Replies
6
Views
881
730virgil
7
L
Something different today
Replies
2
Views
223
Richard G.
R
T
times have sure changed
Replies
9
Views
903
Texasmark
T
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.

Copyright © 1997-2024 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

Back
Top