853 Auxillary Hydraulic Solenoids

[cwjohndeere]

Good evening everyone, just thought I would share some information to possibly save someone some trouble down the road. The auxillary hydraulic solenoids in the "Apitech" valve have been leaking oil from the cartridge itself meaning I'm guessing that the stem of the cartridges were worn through. I had to change one of them when I first purchased the machine since it was leaking so bad and I ordered it through the bobcat dealer to the tune of around $300.00, recently the other cartridge began leaking worse so I did some talking with the local Parker distributor (Parker bought Apitech in the 90's) and he was able to find me a replacement part for $130.00, less than half the cost from bobcat. The part number is VS1320-0111. The only difference is the electrical connector, the machine uses a two pin metri-pack connector which you cannot get from parker, this solenoid comes with a weatherpack connector. I just cut the connectors off of both the harness and the solenoid and crimped on a deutsch connector I would imagine though that you could use whatever kind of connector you wanted though or even a butt connector if you wanted. My machine is an 853 with the BOSS controller I'm not sure if other versions of the machine will be different so this probably will not apply to all 853's. Hmm I was going to post some pictures but I cant figure out how.

 

[Tazza]

Great detective work. You did well being able to track down the part direct from Parker, it's rare to have success. I'd love to know what the aux hydraulic stems are, i'd think most of the parts bobcat use are not specific to them, just finding them is the issue.

 

[cwjohndeere]

Great detective work. You did well being able to track down the part direct from Parker, it's rare to have success. I'd love to know what the aux hydraulic stems are, i'd think most of the parts bobcat use are not specific to them, just finding them is the issue.

Yesterday I decided to cut the old solenoid apart to discover why it was leaking. These are built nothing like I would have figured they would be. They don't have a stem at all, the coil and a steel core forming the magnet fill up the entire end of the cartridge and how they function is the magnet pulls a small steel wafer against a wave washer used for spring tension. The wafer gets pulled away from a small orifice in the center of the body allowing pilot pressure out of the orifice and back out through two holes that connect with the portion of the cartridge that screws into the body of the valve. The way they are designed the coil of the solenoid is exposed to the hydraulic oil all the time I'm guessing only pilot pressure though. This explains why my oil leak was coming out of the wires in the coil, whatever sealant was used in there had hardened over the past twenty years and begun to let oil seep past. The whole assembly (the coil and the threaded portion)is all crimped together there are no individually replaceable parts. A pretty interesting design.

 

[Tazza]

Yesterday I decided to cut the old solenoid apart to discover why it was leaking. These are built nothing like I would have figured they would be. They don't have a stem at all, the coil and a steel core forming the magnet fill up the entire end of the cartridge and how they function is the magnet pulls a small steel wafer against a wave washer used for spring tension. The wafer gets pulled away from a small orifice in the center of the body allowing pilot pressure out of the orifice and back out through two holes that connect with the portion of the cartridge that screws into the body of the valve. The way they are designed the coil of the solenoid is exposed to the hydraulic oil all the time I'm guessing only pilot pressure though. This explains why my oil leak was coming out of the wires in the coil, whatever sealant was used in there had hardened over the past twenty years and begun to let oil seep past. The whole assembly (the coil and the threaded portion)is all crimped together there are no individually replaceable parts. A pretty interesting design.

Seems like a pretty simple device. Shame they didn't come up with a better way of sealing the wires though, charge pressure isn't that high, but any small gaps, it will slowly push out.