2001 773G - Control Valve leak Bonnet

[Quadordie]

Need help, Have a 773G Turbo. Just started leaking horriblely at the back (engine side) of the control valve. I started it, lifted the cab and it runs out of the "bonnet". The bonnet is what the parts manual refers to the part as. They are covered with a green boot (plastic boot, like a cover on a bearing buddy). Anybody have any idea how to fix this?

 

[Quadordie]

I believe it is the upper bonnet (closest to seat) and it has a small hole in the center of the bonnet (the bonnet is a metal circle about 1 1/2 inches in diameter). thanks.

 

[Quadordie]

I believe it is the upper bonnet (closest to seat) and it has a small hole in the center of the bonnet (the bonnet is a metal circle about 1 1/2 inches in diameter). thanks.

Is it possible it just needs new covers/caps for the Bonnet?

 

[Tazza]

Is it possible it just needs new covers/caps for the Bonnet?

Its probably a bad seal on the spool. You will need to pull it out and replace the damaged seals. Access isn't great, but can be done without removing the control block.

 

[mrdeere1959]

Its probably a bad seal on the spool. You will need to pull it out and replace the damaged seals. Access isn't great, but can be done without removing the control block.

I agree. change the spool valves seals. If your going to do one spool go ahead a do both. It only takes a few more minutes, you already have the oil drained and some of the linkage removed

 

[Quadordie]

It was the spool seal. Pretty easy to replace, just took my time and kept as clean as possible. Overall, looked much worse than actually was. Replaced both the upper and lower spool seals and it doesn't leak a drop...for now! Thanks.

 

[Tazza]

It was the spool seal. Pretty easy to replace, just took my time and kept as clean as possible. Overall, looked much worse than actually was. Replaced both the upper and lower spool seals and it doesn't leak a drop...for now! Thanks.

They are a pain to access, but if you take your time, its not that bad as you have found. Glad its all sorted out now.