Davis Loader - Source for Hydraulic Parts?

Inno · Nov 11, 2009

Hi all, I just signed up to the forum. Looks like there is a wealth of great information and great people here.
I recently purchased a MF 202 Industrial (Workbull) with a Davis 102 Loader and 220 backhoe.
One of the spool valves for the dump control on the loader is slightly damaged. It looks like someone has attempted a repair previously and left it not quite round so now when you pull the lever to tilt the bucket up you get a nice shower of hydraulic fluid. It only happens when you pull it more than half way back.
So I am wondering if anyone might have a source for maybe some used or new old stock parts for this unit. There are many other things that will need to be looked after on this tractor but the major mechanicals are all working at the moment. I plan on finessing it a little bit here and there.

Thanks in advance and I look forward to looking around here a bit more.

Anonymous-0 · Nov 11, 2009

Valves usually aren't successfully repaired, only replaced. And are usually generic so you buy what's available at your favorite source of hydraulic parts like Northern Tool or Baum Hydraulics.

Gerald J.

Inno · Nov 11, 2009

I guess that would explain why there are no parts available. It just seems so much simpler and more cost effective to replace just the parts needed.

Anonymous-0 · Nov 11, 2009

True enough but the valve spool is made to fit the valve body with too small a clearance for oil to leak past. When those parts wear and the spool is spilling oil out the end there are no replaceable parts to fix it. Some valves do have an o-ring seal on the ends, but the rest of the valve is so worn that it won't control right. The valve could be built with a bunch of o-rings, but putting an o-ring in a groove 4" into the valve body in a hole less than an inch diameter would try your patience to the extreme. But then the valve would be stiff and you'd not be able to control it smoothly. So they don't make it fixable.

Gerald J.

supergrumpy · Nov 11, 2009

if your loader is like my 200, the backhoe gets its oil from loader valve body

"surplus center" has lots of loader valves and other hydraulic kinda stuff but this stuff isn't cheap

might be good idea to haunt the boneyards

chuck41 · Nov 11, 2009

Did you try MF for a new spool ? p/n 1752344m1.
They are easy to put in. The seal is 1752350m1.
Chuck

Inno · Nov 11, 2009

(quoted from post at 20:26:35 11/11/09) Did you try MF for a new spool ? p/n 1752344m1.
They are easy to put in. The seal is 1752350m1.
Chuck

Yes, I got the part numbers from the Agco parts site and called one of the dealers listed. The guy told me they were discontinued/obsolete but he tried two other sources that he knew of for NOS parts and came up with nothing.
I wonder if it might be worth going through all the dealers listed on the Agco site and maybe I'll get lucky. I would think they should all be computer linked but maybe not.
I had them out this past weekend because the split ring came off the bottom of the other one so I had to take it all apart.
I had also considered taking it to a machine shop and maybe just having them take off enough material to make it round again and finding a seal with a slightly smaller inside diameter.........maybe this will not work because the clearances inside the valve body need to be so close.

Inno · Nov 12, 2009

(quoted from post at 20:19:53 11/11/09) if your loader is like my 200, the backhoe gets its oil from loader valve body

"surplus center" has lots of loader valves and other hydraulic kinda stuff but this stuff isn't cheap

might be good idea to haunt the boneyards

The stuff at "surplus center" is better priced than some I've seen.
So if I were to go that route I should roughly match the GPM of my current valve which is 20GPM according to the manual. If I exceed this I'm assuming my hydraulics will be quicker? Also assuming that it will put more load on the pump etc. so probably best to stick close to what I have now.
I should also look for a pressure relief valve that is adjustable in the range of the one I have now at 2150psi. Other than those factors and of course making sure it is double acting, is there anything else I should be looking for when selecting a replacement valve? Other than mounting etc.

Anonymous-0 · Nov 12, 2009

The flow rate of the valve needs to be at least as great as the flow rated needed by the cylinders. You don't need 20 gpm on most loader cylinders unless you are trying to toss material. 5 gpm is often just fine for 3" cylinders.

Consider a loader valve with float for the main boom, that makes cleaning snow off surfaces many times easier.

Yup, you need the pressure relief valve for an open center system and it needs to be set at a reasonable value for the pump in use.

Gerald J.

Inno · Nov 12, 2009

Thanks for the info Gerald.
So for most applications 20 would be overkill. I do not want to toss things, I'm guessing lower flow rate would be easier on all moving parts of the loader and on the hydraulic system.

I am somewhat familiar with the float function but not entirely sure how it works.
From what I understand you set the bucket to where you want it and it will more or less follow the contour of whatever it is you are plowing/grading without digging in or becoming too far off the ground. Is this correct?

Anonymous-0 · Nov 12, 2009

You also need the open center valve to pass all the hydrauic pump volume which is likely less than 20 gpm.

With the float function, you set the bucket on the ground, then it stays on the ground rising and falling as needed to stay on the ground. If you go to float with the bucket in the air it will fall instantly. That keeps you from digging into the ground when the ground rises, the tractor back tires go over a hump or the tractor front tires fall in a hole. Make snow moving much happier.

Usually the float position is plumbed so its a notch on the spool past the lowering position.

Gerald.

Anonymous-0 · Nov 13, 2009

A lot of MF loaders used a 17 gpm pump and with a backhoe an even higher capacity like 21 gpm. 3 or even 5 gpm would be pitifully slow, especially with 3 inch cylinders which I doubt you have. On the hoe you would dig faster with a shovel! Hoes often need at least 2 functions operating at the same time. If you replace the valve for the loader, you need a power beyond adaptor to direct fluid to the hoe valve. Float position is for back blading only and should NEVER be used while driving forward. If you dig in or hit something, there is nothing to stop the lift cylinders from from bottoming out and catapulting you out of the seat at 50 mph. Bulldozers also have float position as do skid steers. It lets the blade or bucket follow ground contours while reversing without digging in. On a tractor it allows you to steer as well. If you just put the bucket down and lifted the front tires, you'd have no steering. With a good control valve, it is easy to control the speed of cylinders from fast to slow depending on what you're doing. Manufacturers are pretty good about sizing the right pump for the machine. Stick to something close. Dave

Inno · Nov 13, 2009

All of this has got me thinking about a few things.

First of all, I could leave the factory original valve in place to retain proper functionality to the backhoe and use the one good spool to replace the bad one on the dump lever for the loader bucket.
Then I could simply add a new single spool valve with float for the loader arms.
I have a background in electronics so I am guessing that the same rules for series and parallel circuits apply to hydraulics as they do for electrical circuits. I will need to get my head around this before I start.

Thanks again for all the responses

supergrumpy · Nov 13, 2009

hydralics per MF isn't quite like moving electrons around, I have to wrestle with all the considerations involved

open center valves at rest allow the pump to push the oil right back to the tank, the oil is always flowing

you will have a nice plumbing challenge trying to hook up a loader tilt valve next to your OEM valve while allowing return oil back to the tank

an awful lot of engineering and clever design is built into those spool valves

Inno · Nov 13, 2009

That is somewhat what I expected to hear after thinking about it some more.
Easier to install a whole new set of valves for the loader rather than trying to use some of what is already there?

GaryF · Nov 13, 2009

Listen to what Supergrumpy is telling you. You are better off trying to find a new 2 spool valve with powerbeyond and maybe a float position. I'm not even sure that float was available in those older loaders (the 200 may have had it and self leveling as an option)

Lon Jackson · Jan 29, 2016

Anyone know where I can find either a front mount (crank driven) hydraulic pump or possibly a PTO driven hydraulic pump that will fit a TO-35 Ferguson tractor

Davis Loader - Source for Hydraulic Parts?

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