NEW MEMBER!! resealing 4625 main control valve

[artnadam]

HI, I'm a new owner of an older 4625--trying to dry it up, main leak was the old plastic hyd. sight glass--replaced that with new style, no leaks. Now main source of an annoying weeping leak is the main control valve. It functions fine, replacement new valve is almost $1600 !!-crazy!! I bought replacement seals for the two spools and a few O rings. Main question--can I replace the four spool seals without removing the spools?? If I have to remove them, will I have to drain the fluid of the entire system to below the valve level to prevent gravity loss ?? Anybody have any pointers or experience doing this? Thanks, Art Young 717-648-3070

 

[SkidRoe]

Welcome to the Forum!
Providing you have room on either end of the spools, you should be able to replace them without pulling them out completely.
Disconnect the linkage and remove the rear cover and centering spring assembly. You should then be able to push the spool in to expose the seals, one side at a time.
Hope that makes sense...
Cheers - SR

 

[artnadam]

Welcome to the Forum!
Providing you have room on either end of the spools, you should be able to replace them without pulling them out completely.
Disconnect the linkage and remove the rear cover and centering spring assembly. You should then be able to push the spool in to expose the seals, one side at a time.
Hope that makes sense...
Cheers - SR

Thanks, SkidRoe! Sounds reasonable, I'll give it a try when I can get it on the schedule. Thanks for the input. Artnadam

 

[4510]

I have thrown an old shop vac on the hydraulic tank fill and stopped the tank from draining. I have read that others have had luck with this as well. My buddy did a sight glass on a full tank using the shop vac technique. A lengthy job might require you to drain it, but worth a try if you can swap seals quickly.

 

[artnadam]

I have thrown an old shop vac on the hydraulic tank fill and stopped the tank from draining. I have read that others have had luck with this as well. My buddy did a sight glass on a full tank using the shop vac technique. A lengthy job might require you to drain it, but worth a try if you can swap seals quickly.

Thanks, 4510---thats a great idea!! Ill give it a try when I get ready for the project Art Young

 

[SkidRoe]

Thanks, 4510---thats a great idea!! Ill give it a try when I get ready for the project Art Young

I can vouch for the shop vac method mentioned by 4510 - it works well.
HTH - SR

 

[artnadam]

I can vouch for the shop vac method mentioned by 4510 - it works well.
HTH - SR

Thanks,SR, good to know its a proven concept.