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Trying to track down a leak on my Hydraulic steering assembly. The leak is from the front of the hydraulic control value as shown in the exploded attached TM view. Looking at my components I am missing J & L which are 2 O rings but they are not really key O ring elements in the whole design of the item. These look more like external dirt seals versus the oil seals.
Problem:
After running for a period of time 30 minutes and steering alot, hydo oil is pissing out of the hydro control valve in the front and of the unit towards the cover end or left in these pictures. It will drain out about 1 cup and then stop. This happens even with the motor turned off. It will not exhibit these problems if you just get the engine hot it seems to require alot of steering to make it leak. I have not been able to confirm if it leaks when driving. My diagnosis is that it is leaking from the front seal on the socket into the front cover.
Questions
1.) Lets assume the problem is in the pressure relief value, looking at the TM the pressure relief is set to 750 lbs which seems that the system is designed to be a closed system and only relief in case of high pressure? If the system is designed to be more of an open system like the air commpressor then there should be a bleed off of pressure as necessary but would leak hydraulic oil and thus I do not believe the system is an open system but more closed and the relief only used in terms of emergency thus not part of my problem. Can anyone shed any light on the actual operation of the pressure relief valve. Does anyone know the operating pressure of the system?
2.) Looking at the spool and the actual drawing there 2 machined grooves on the left end of the spool but only one O ring. The TM confirms this is the design but it would make more sense to add another O ring into the assembly. I find it hard to believe that a single O ring is a good seal for 250lbs or more pressure.
Action Plan at the moment
1.) Replace O rings
2.) Add additional O ring to the left front of the spool
3.) Dependant on answers related to the relief value, take apart relief valve
Any additional insight or ideas is appreciated.
Problem:
After running for a period of time 30 minutes and steering alot, hydo oil is pissing out of the hydro control valve in the front and of the unit towards the cover end or left in these pictures. It will drain out about 1 cup and then stop. This happens even with the motor turned off. It will not exhibit these problems if you just get the engine hot it seems to require alot of steering to make it leak. I have not been able to confirm if it leaks when driving. My diagnosis is that it is leaking from the front seal on the socket into the front cover.
Questions
1.) Lets assume the problem is in the pressure relief value, looking at the TM the pressure relief is set to 750 lbs which seems that the system is designed to be a closed system and only relief in case of high pressure? If the system is designed to be more of an open system like the air commpressor then there should be a bleed off of pressure as necessary but would leak hydraulic oil and thus I do not believe the system is an open system but more closed and the relief only used in terms of emergency thus not part of my problem. Can anyone shed any light on the actual operation of the pressure relief valve. Does anyone know the operating pressure of the system?
2.) Looking at the spool and the actual drawing there 2 machined grooves on the left end of the spool but only one O ring. The TM confirms this is the design but it would make more sense to add another O ring into the assembly. I find it hard to believe that a single O ring is a good seal for 250lbs or more pressure.
Action Plan at the moment
1.) Replace O rings
2.) Add additional O ring to the left front of the spool
3.) Dependant on answers related to the relief value, take apart relief valve
Any additional insight or ideas is appreciated.
Attachments
Last edited:
. I will post part numbers later. The first machined groove is necessary to get the snap ring installed and a o ring will not provide any value. It takes a good greasing to install the spool. It is all back together now. One tip is to install the snap ring before pushing the spool all the way into the housing. Once installed you can push the spool all the way flush to the back of the housing.
