VAC Hydraulics

[Victor Shields]

I have a 51 VAC Case and the hydro don't work unless I pour the oil into them like crazy! It leaks out the breather port.. Would it be possible to start over with some other kind of hydro since the 60 yr. old tractor is nearly impossible to find those parts for or find someone who wants to work on them for a reasonable price. Would an electric hydro lift be able to lift a single bottom plow and or a 4 ft. rotatiller? Or would another solution work? I am not very mechanical but would give something a try since I have spent too much on this old tractor to quit now!!

 

[Soundguy]

so lets see.. the hyds are not working.. and you are not mechanical' enough to fix them..... yet you feel you would like to completely fabricate a new system instead.. as an option, vs repairing the existing setup, for which you can at least find parts and help for.

did i get that right?

I have the email of a guy that has SOME vac parts.. and big salvage yards like wengers of PA usually have entire parted tractors..

here is another guy:

Case VAC Parts

i've bought plenty of allis chalmers parts from him.

he has a pump and valve listed as well as lines and some rockshafts and brackets..

what ya lookin for specifically?

 

[KYErik]

I installed a saginaw power steering pump from a 78 chevy truck onto my 1943 Case SC. The tractor came with no hydraulic system at all.

The power steering pump has an internal pressure relief around 1200 psi and the stock reservoir was just right to run a 3x8 cylinder. The biggest down side is that I had to remove the generator to install the PS pump. I also had to weld a wide pulley onto the narrow stock PS pulley since the fan belt was the wide size.

The 3"x8" cylinder was enough to lift a 6 ft bushhog (I welded up a "custom" 3 pt hitch) and make the front end of the tractor really light.

If you aren't into custom work, then a 12 volt electric hydraulic pump should work fine- it just might be a bit slower than your old system.

 

[Victor Shields]

I don't know where to start, even to determine what parts I need to fix the hydro. All I know is it does not work! I can see oil running out the breather pipe and I don't even know where the hydro pump is located. I am guessing it is either at the front of the engine since that is where the hoses go. The hydro system may also be a part of the belt pulley setup near/under the steering wheel column near where the breather is leaking. That is where the reservoir for the oil is located. You can check the oil level there by opening a plug. It seems to me that the hydro oil reservior and the oil reservoir for the rear end of the tractor are located inside the main "tube" frame of the tractor. Could they be allowing the oil from the hydro to spill into the rearend gear box because of a bad seal? I understand the rockshaft is what lifts what I would call the lift arms of the 3 point hitch, that is under the seat and has what I am guessing is the hydro lift cylinder inside a casing at that location? I did have a repair manual but it is so poorly reproduced that is is hard to read let alone understand the illustrations. I gave the manual to a guy that fixed the carberator and put in an electronic ignition. He unfortunately died without returning it, I did get the tractor back however! The tractor now starts good and runs pretty good except the governor is not working properly and the engine surges when pulling heavy. Thanks for the patience as I learn from you all about the mechanics of this tractor.

 

[CTPhil]

I can't help too much, but the can shaped thing on top of the rockshaft contains a piston with a leather cup to provide the pressure to raise the rockshaft. The seal between the axle and torque tube was known to sometimes fail. As far as I know the belt pulley is strictly mechanical. If you have tubes coming from the front of the engine, you likely have an engine mounted pump. There are usually a lot of parts for VAC's on ebay.

 

[Soundguy]

hre's what you do:

1, BUY A SERVICE MANUAL.

2, READ IT.

3, Come back here and start asking questions. Someone / many of us, should be able to help you thru this.

You are smart enought to use a modern vehicle and operate a computer... you should have no problem tackling a 70 year old tractor..

may the force bewith you!

soundguy

 

[CTPhil]

I find a parts manual to be more helpful. I have a shelf full of maintenance manuals I rarely consult, I usually end up disappointed when I try to use them. Most are written when something is new and are based on theory. There's nothing like an account from someone who has actually done a repair and has discovered all of the things the manual doesn't tell you.

 

[Victor Shields]

Thanks for the replies, they are helpful. One person says buy a maintance manual another person says buy a parts manual. I had the maintance one and lost it and it wasn't all that helpful due to it's poor quality. What is a parts manual and where do I get it and/or a maintance one? If I were to start by taking off the hydro cylinder under the seat to see if the cup seal were bad would that make the tractor unuseable for pulling my cart etc. for work I need to do this winter? I guess I would have to take off the hydro pump first to keep it from running oil out the lines? If I did that would that make the tractor unuseable too or could it be put back together without the hydralic pump and cyclinder? Maybe this is a good tiime to ask the wife if I can buy another cheap old tractor to use while this one is being fixed?? All you can do is pray for me on that one!!

 

[CTPhil]

There's no real need any more to buy a parts manual, just go here and type VAC into the search.

The cup seal would be last on my list to mess with, if it's failing the hitch arms will be weak or won't rise.

I wouldn't take off the pump unless to fix it, it's absence will leave an opening on the engine.

 

[Victor Shields]

Thanks I will leave the pump alone for the time being. The cylinder seal could be the problem since the arms don't raise at all now. I am unable to open the link to the manual's site. Try sending it again please. Maybe it is offline for the Christmas season so I will try later too.

 

[J_J]

Have you checked the pressure, and if not, why not.

Have you removed any hoses to check flow?

Have you checked the basics, fluid level in reservoir, filter, filter screen, etc.

Are you using the correct fluid?

What color is the fluid?

If you are losing fluid, where is it going?

Even a manual might not tell you the theory of operation.

For instance, just where does that 2000 psi of pressure come from?

 

[CTPhil]

Try the link now.

I agree with the previous poster about basics. Trying the simple stuff first is always a good way to go.

 

[Victor Shields]

HI, I don't have a pressure test device but I know the pressure is low or the 3 point would raise? The leak is going back into the torque tube from the breather since that is the way I plumbed it to go. It was going out the breather and onto the ground. I put the correct oil into it when I refurbished the tractor about 10 years ago and have since replaced it with regular Hydro oil when told to do so by a reputable tractor mechanic. The oil level is up to the overflow level when checked at the proper place. The tractor had no hydro oil filter nor screen when I got it and I assume did not have one at manufactoring in 1951? Another old Case mechanic said he figured I didn't need one if the oil is clean and if it had worked without it for 40 yrs. I guess I have checked all the simple things first as you all said but am open to more ideas.