Bobcat 743 control valve and relief valve

[markool]

I am working with my control valve rebuild, valve block inspection and new seals . My 743 serial number is 5019-M-23834 and it has one piece cast iron control valve. Now the problem is relief valve o-rings and back-up rings position. In the control valve component repair manual shows different positions for the o-rings and back-up rings vs parts manual. So, what is correct locations for the rings?

 

[markool]

I forgot to mention it is main relief valve.

 

[markool]

I forgot to mention it is main relief valve.

I will reply to myself. Control valve component repair manual has an error in the text of the valve picture. In the picture, the position of the rings is correct.

 

[Tazza]

I will reply to myself. Control valve component repair manual has an error in the text of the valve picture. In the picture, the position of the rings is correct.

Glad you worked it out.
As a general rule, a backup ring is opposite the pressure side. So the Orings face the pressure, the backup ring sits behind the Oring.
Same with hydraulic seals, the lips face the pressure side, the more pressure applied to them, the harder the push, creating a seal.

 

[markool]

Glad you worked it out.
As a general rule, a backup ring is opposite the pressure side. So the Orings face the pressure, the backup ring sits behind the Oring.
Same with hydraulic seals, the lips face the pressure side, the more pressure applied to them, the harder the push, creating a seal.

Yes, that's exactly what I thought also.