Adding a Hydraulic cylinder

[RaymondDurban]

When adding a small cylinder to the 54 blade to angle it, is it absolutely necessary to use a bypass block or can you connect directly to the ports on the lines going into the touch control block?

[John *.?-!.* cub owner]

If you do not use the block to divert the fluid to the external valve before it goes to the TC, you will only have pressure to angle the blade when the touch control is lifting or lowering.

[RaymondDurban]

I take it that's because the TC block has an internal bypass? So no pressure will be applied to the external valve due to the TC block bypassing until activated?
So, what happens when the external valve needs to be removed for some reason? Will the bypass block also need to the removed and the Hydraulics set back as factory? Or can a hose be looped around where the external valve was plumed in?

[John *.?-!.* cub owner]

you are correct, the TC is what is called open center, the oil just circulates at low pressure till used. You need an external valve that does the same, so when it is not used the oil will circulate through the TC. If you take the blade off you can just leave valve mounted and in center position, or replace the lines going to the valve with a bypass hose.

[RaymondDurban]

Thanks John!

[Rudi]

Raymond:

One of the simplest to install is a Cessna-Eaton valve off of a Cub Cadet. I acquired mine from Joes Outdoor Power - each of them for less than $20.00 - well actually I got 3 of them for $9.99 plus shipping. They are simple and kind of fitting since they are Cub Cadet valves.

The by-pass block that TM has is a good one - for the Cub and A - By-Pass Block. If I am not mistaken, I think Earl makes a by-pass block very similar to the ones Rick made for me. They are Cub specific and match the manifold boss and manifold itself for the TC - can't even tell it is there. Either one will be a great choice.

Take your time at it. It doesn't take much to deadhead -- ask me, I have done it a number of times.

[RaymondDurban]

Thanks Rudi. The application wasn't for me, but rather a question that was brought up this past weekend up at Bob's.
One of the guys there wanted to connect a cylinder to his snow blade, and had the valve, cylinder, bypass block and fittings to do this, but no hoses. We didn't connect anything for fear of dead-heading the pump with no where for the fluid to go, but as we stood around the tractor, all the questions above we're discussed.
None of us had ever done the conversion/mod before, so we moved on to other stuff to occupy our time!

[Rudi]

Raymond:

Once I got over the fear of actually doing the mod, it was a lot of fun. I am sure you and Bob will have a blast helping out should the other guy decide to do this.

[IH59cub]

Thanks Raymond for asking the bypass question.
Since last week I installed all the connections, had the hoses made and have everything connected except for installing the by-pass block. I need to get a jug of Hytran so when I install the bypass I have some clean oil to put back in it. Which brings me to a question...Is there any trick/procedure to putting in the oil and getting it through all the hoses/valves/connections etc. without blowing something up that I don't want to?

[Rudi]

Use a funnel with a stiff flexible hose that will fit into the fill port, or install an adapter like what I did at one point.



After you get say 3/4's of the Hy-Tran in, start the Cub up and start cycling the hydraulics .. up and down etc., and keep on doing it until you reach the top of the fill port which is what I do. If you are plumbed correctly you shouldn't deadhead at all.

[Matt Kirsch]

Gonna put my "know-it-all" hat on for a minute...

Open center hydraulic systems only work if there is one main loop for the oil to flow through. Valves block off that main loop and divert the oil to a cylinder. Any oil returning from the cylinder is dumped back into the loop.

That means it would need to come from the reservoir, go through the pump, go through the aux valve, go through the TC, and go back into the reservoir.

The bypass block diverts the oil from the pump and sends it to the aux valve.

If you just connect the aux valve to the plugs on the side of the manifold, you create TWO loops for the oil to flow through. One being the aux valve, and the other being the TC.

Oil will take the path of least resistance. With two loops, nothing will work because there will always be one clear path for the oil to take back to the reservoir without actually doing anything. Path A is blocked, so the oil goes down path B instead of angling the blade or moving the TC rockshaft.

[IH59cub]

Rudi,
Thanks for the info. I like your fill adapter. If you can remember can you tell me what parts you put on it. I was going to do something like that put couldn't get the right reducer to replace the reservoir plug, it seems the threads were the difficult part, but that was a couple of brain cells ago.

[Rudi]

Most TC's Reservoirs had a normal pipe plug thread, but some had an odd-ball thread. Before I measured it properly, I made a couple of the adapters for it. Still have them (3) and if yours needs one simply let me know. The Wouldn't This Frost Your Heinie ? thread would be kinda useful I think.

Threads should be 3/4" NPT but could actually be 7/8"-18NC. There are other threads that document the process from adding the by-pass for my Blade project to the Splitter Project. Most are in the CBoK and in the How To Forum.

[Jim Becker]

OK, this gets complicated. Unless you are ready for your head to spin, stop reading now.

The Touch-Control is a closed valve system. That is, when the control valve is in the neutral position oil can not flow through it. The pump supplies a flow of oil into the main Touch-Control block. This oil can take any of 3 paths back to the reservoir.

1) When the control valve is in neutral, the flow returns directly to the reservoir through an open pressure regulator valve.

2) When the control valve is activated, the regulator valve closes and flow is directed through the control valve to the piston. Oil on the opposite end of the cylinder returns to the reservoir.

3) When the control valve is activated and the cylinder can not move (blocked, overloaded or end of stroke), the safety (relief) valve opens to return oil to the reservoir. This is generally a bad situation. The oil is under maximum pressure, the engine is loaded and a lot of heat is produced.

If the flow is prevented from all 3 of these paths, the system is dead ended and a lot of damage happens very quickly.

If you want to add an auxiliary control valve and cylinder, there are 2 ways to do it. One method allows use of the internal Touch-Control cylinder (and thus the rockshaft) while the other one blocks/disables it. Both methods require the added control valve to be open center and require addition of an external safety valve. The safety valve may be incorporated into the added control valve. In both cases, the flow from the pump is captured between the pump and the main Touch-Control block. This is a point BEFORE the flow reaches any of the 3 individual paths listed above. Thus, you are AT RISK of dead ending the pump if any errors are made in connecting the addtional components. You have to make sure there is ALWAYS some path back to the reservoir. This path can be directly from an added component (into the filler plug opening) or into the original pressure inlet to the main TC block (where path 3 is always available).

There are many designs of auxiliary valves. I am only going to describe 2.
1) Simple open center valve, one inlet, one outlet and 1 or 2 feeds to the (1 or 2 way) cylinder. A built in relief valve can dump flow directly from the inlet to the outlet when the cylinder is blocked.
2) An open center valve with the same connections as above plus a return connection. The built in relief valve dumps flow into the return connection rather than the outlet. Return flow from the cylinder also goes to the return connection. Thus flow only reaches the outlet when the valve is in neutral.

If you have an auxiliary valve without a built in relief valve, you can add a separate relief valve in front of the control valve. The safty return from the relief valve is equivalent to the return line from the second type valve and needs to be run back to the reservoir.

To use an external valve/cylinder with the rockshaft disabled:
Tap into the high pressure connection on the Touch-Control manifold. Run this to the inlet of either type valve. The outlet (and separate return) from the valve connects to the reservoir through the filler. You then cycle the rockshaft to the rear position, block or chain the rockshaft in this position and move the control lever to the forward position. This forces the flow to inside the unit the safety valve (path 3). But the flow is diverted upstream to the auxiliary valve and back to the resarvoir. Using this method, the internal safety valve is still in play and the pressure relief of the external valve is not required.

To use an external valve/cylinder with the rockshaft in service:
This requires addition of a diverter block (or equivalent modifications) between the manifold and the Touch-Control block. The added block forces all flow from the pump to the auxiliary valve AND BLOCKS FLOW TO THE SAFETY VALVE!!. The flow from the pump is connected to the inlet of the auxiliary valve. Output from the auxiliary valve is returned to the diverter block where it can continue into the main block and take one of the 3 normal paths that operate the Touch-Control system. In this set-up, you need to have the second type valve and connect the return line directly to the reservoir. If you happen to block both the rockshaft and the auxiliary cylinder at the same time, both safety valves will come into play at the same time. If you have the type 1 control valve, output from its safety valve will be input to the other one. The pressures will add to each other. If both open at, for example 1,200#, the pump will see 2,400#. That is way over the design limits, potentially doing the same damage as dead ending the system.

The bottom line, there are a couple ways to do this. Which you choose depends on what you want to accomplish annd what you want to spend. In any case, be sure of what you are doing to avoid some expensive mistakes.

[IH59cub]

Danke again! It's nice to know that I'm not totally nuts....yet!