Hydraulic lift pressure adjustment

[hayden]

I bought a Salsco 824 chipper for my B2910, and my dealer warned me that I might have trouble lifting the chipper with my 3PH. He was right.

I decided to tweek up the hydraulic pressure to get it to lift, and spent some time with one of the mechanics at my local dealer discussing the topic. He gave me all the obligatory warninings, etc., and I decided that I'd go no more than 10% over spec, where spec pressure is 2000 psi (actually something like 1970, but close enough).

First step was installing a pressure guage. I placed it in the supply line coming into the loader valve. That way it could read pressure for any of my implements. Once I got it installed, my first discovery was that my system was releasing around 1700 psi! No wonder the 3PH couldn't lift the chipper. I first set the loader relief to 2200 psi so it would be above the 3PH relief. Otherwise the loader relief would go first and I wouldn't really know where the 3PH was set.

The 3PH relief is set with shims and is a nusance to change. The machnic was kind enough to give me a shim he had left over so I got one adjustment I could make. The relief plug is on top of the 3PH case and access requires removal of the seat and rear fender support cross member. I have a heavy duty 3PH bracket and that had to be losened up too. With all that done I was able to remove the plug, add the shim, and replace the plug. A quick test showed the pressure up to about 1950psi (right at spec), and the chipper lifted without trouble.

With everything put back together, I'm back in business, and I didn't have to overpower the hydraulics.

 

[JohnMiller3]

Hi Peter,

Do you have a picture of the location...? /forums/images/graemlins/smile.gif

 

[JerryG]

hayden,
As John said, do you have any pictures. I am sure several of us would like to see more.

 

[hayden]

Not of the relief plug, but I do have some of the pressure gauge installation. I'll post them a bit later.

The relief plug is the only ~3/4" bolt head on top of the 3PH housing. I originally identified it from the repair manual and parts manual, and after I got the seat removed there was no mistaking it. I was able to get a wrench on it and back out the plug without removing the support stay, but the plug wouldn't withdraw completely so I had to disassemble further.

 

[Pks]

Do you know the thickness of that shim?

 

[hayden]

The shim I added was .040", and is the thickest shim available. You are supposed to combine them to reach the desired release pressure. The .040" shim raised the pressure by about 200psi.

I was planning to buy a combination of thicknesses until the mechanic offered me a .040 shim he had left over, so I figured I give it a try.

 

[Anonymous Poster]

Just out of curiousity, does anyone know if this kind of adjustment is avialable on the BX tractors? TYIA

 

[jrlichina]

Yes the BX has the same type of relief valve design. You need to add shims to increase the pressure. These shims come in various thicknesses.

 

[Pks]

Thanks hayden,

Could you now describe where you placed the pressure gage in order to measure the 3 pt lift pressure?

 

[Anonymous Poster]

I spent some time with all the "exploded" drawings I have for the BX and for the life of me, I can't find anything called a relief valve! I'm not necessarily going to do this kind of mod, but would like to know more about my machine. Point the way, my friend...and thanks in advance for your help!