Adding rear hydraulics to L2250

[repete]

Not really... I inherited a bridgeport, but have not had a chance to learn how to use it. My background is as an auto tech, not a machinist.

With your bridgeport this should be a fairly simple project. The biggest issue will be cutting the groove for the O rings to be retained in. You can get the dimensions off the cover plate you remove. I will look at my hose routing and tell you which is the pressure and which is the return line (holes). I am hesitant to remove mine as it has been on for many years and if the bolt snaps in the threads I am in big trouble. I suggest you get the softest steel you can get from the supplier as it will make the machining much easier. Fortunately with O rings, you do not need a gasket quality finish. I suggest when you assemble it you use some silicone to not allow water in between the surfaces though. Have fun learning. As for careers, I burned stuff down for a living and started machining when I was 59, two years ago.

 

[bjorn773]

It's an excuse to spend some learning time on the mill. Earlier it was mentioned that the kubota valve was open center. The valve I'm looking at indicates it can be converted to closed center or power beyond. Does that mean it is normally set up open center and if needed can be changed?

Prince Hydraulic Control Valve 8 GPM 2 Spool MB21BB5C1 | eBay

 

[teg]

...the kubota valve was open center. The valve I'm looking at indicates it can be converted to closed center or power beyond. Does that mean it is normally set up open center and if needed can be changed?

All that was mentioned before... MAY NOT apply here.

Since it's only two lines... I don't know but yes, the valve can be modified from open to close and with power beyond or not. I'm not sure which way the valve needs to be setup...

EDIT: I think the 3 options are; open with power beyond; open without power beyond or closed. I'm not sure of the differences and how it relates to your setup.

 

[J_J]

FYI, the seals in a hyd valve are not designed for pressure, but to keep water/debris out.

You should also know that the spools are selected for a precision fit, and they may select 8 to 10 spools before they get one to meet specs.

For this reason, most manufacturers do not sell replacement spools for hyd valves.

What if the bore is out of round, or worn. All the straight spools in the world are not going to make it work right.

Just my take on the situation.

The normal open center valve will come as open center using an IN port and a tank port with the PB port plugged.

To make it PB capable, you remove the plug and add the PB adapter.

To make it closed center, plug the PB port or remove the PB adapter and insert a closed center plug.

http://www.surpluscenter.com/_MoreSpecs/iPrinceMBValves.pdf

 

[s219]

Don't know if it's possible, but could the existing cap be machined to serve as a hydraulics connection plate? Depending on where the ports are located, I wonder if it would be possible to drill and tap some pipe threads into the cap. It likely already has o-ring grooves and o-rings.

The cap for my L3200 was on the side of the transmission case. It was thinner metal, but at the time I remember thinking how easy it would have been to make a replacement with the same pattern if I was trying to use this for generic hydraulics. In the case of the factory valve kit for the L3200, it came with a nicely machined aluminum block that bolted to the case and had the o-ring grooves machined in. Also had some fairly complex internal machining for the PB and return flows to/from the valves. Internal passages were machined and then the outside capped with plugs. The stacking valves bolted onto the block with long studs.

 

[bjorn773]

I'm going to take a closer look at my cover... I may be able to drill and thread it if it is solid. Then I could use 90's to get it routed rearward. If not, I'll try machining a new cover. I am willing to spend some time in lieu of 300 bucks.

 

[Leejohn]

Go for it, you can do it!! If you go to Jerry's auto for your hoses tell Jay, Todd, & Tim I said hi. Post a picture of the plate when you get it done.

 

[bjorn773]

Assuming I can tap in under the seat, I need to run press and ret to the valve. From the valve I just run short hoses to quick connects in back, right. One pair of hoses/quick connects for each spool?

 

[Leejohn]

Yes that's right.

 

[repete]

I'm going to take a closer look at my cover... I may be able to drill and thread it if it is solid. Then I could use 90's to get it routed rearward. If not, I'll try machining a new cover. I am willing to spend some time in lieu of 300 bucks.

How will you separate the O rings and fill the cross connection in the cover plate. I recollect Leejohn saying the O ring was oblong with a machining to allow flow between the two ports.