control valve rebuild, pressure relief valve problem?

[shepherd]

The main control valve on my 773 finally started puking after 10 years of ownership, I knew the valve was going to be very difficult (or impossible) to overhaul as it had lots of rust, so I bought a used valve and gave it a cleaning and seal kit while it was on the bench. All in all, not a bad job if you can stay organized and are good with small parts.. I'm glad that I did it, as I found some seals that were obviously worn, though overall it is in very nice shape. Everything went fine, except for the relief valve. When I removed it, the large ring that seals it against the valve body was wound down into the threads, which seemed strange. And on inspection, theres a part that looks like it was crushed, either accidentally or perhaps peened down on purpose? I can't tell. I removed the valve from my bad unit, and it is crushed sort of the same way. Can anyone tell me what's going on here? I did put the new seals on it, and reinstall it, but I'd like some more info before I fill the system and fire it up. I can't get my laptop to paste the pics in, so I'll post the links one by one in the responses. Copy and paste them to load the images of the valves. Thanks in advance. SD

 

[shepherd]

https://www.flickr.com/photos/24397585@N02/33722846126/in/dateposted-public/

 

[shepherd]

https://www.flickr.com/photos/24397585@N02/33722846126/in/dateposted-public/

https://www.flickr.com/photos/24397585@N02/33607241682/in/dateposted-public/

 

[shepherd]

https://www.flickr.com/photos/24397585@N02/33607241682/in/dateposted-public/

https://www.flickr.com/photos/24397585@N02/33722846426/in/dateposted-public/

 

[shepherd]

https://www.flickr.com/photos/24397585@N02/33722846426/in/dateposted-public/

https://www.flickr.com/photos/24397585@N02/33722846286/in/dateposted-public/

 

[Tazza]

https://www.flickr.com/photos/24397585@N02/33722846286/in/dateposted-public/

Not sure that it's damaged. For it to have been over tightened, it wouldn't have pushed just that part up. Not even sure what that opening is for, i noticed it on mine when i was digging around in it a few weeks ago.
If you are concerned, use the original one, even though the outside is a bit rusty.

 

[shepherd]

Not sure that it's damaged. For it to have been over tightened, it wouldn't have pushed just that part up. Not even sure what that opening is for, i noticed it on mine when i was digging around in it a few weeks ago.
If you are concerned, use the original one, even though the outside is a bit rusty.

Just for the record, to answer my own question, both the dealer service department, and Bud from Buddy's service in ND confirmed that the "dent" on the pressure relief valve is the way it comes from the factory. I've got it all back together and working well

 

[shepherd]

Just for the record, to answer my own question, both the dealer service department, and Bud from Buddy's service in ND confirmed that the "dent" on the pressure relief valve is the way it comes from the factory. I've got it all back together and working well

So, after getting the machine back together and running, out has exhibited a problem that did not exist before the I swapped the valve for a rebuilt one. At several points after getting it running and working again, it has had very jumpy, jerky, loud lift and bucket hydraulics. At first I thought it must be some air in the system, and it would get better. But the problem seems to come and go. Today it was the worst it's been, and the arms and bucket locked up completely for a while. The whole job entailed: swapping the control valve and rebuilding it with a bobcat kit. I split the bics from it, and re sealed everything. Several new lines, a few I made with larger diameter hose than was stock. But, those were all return lines and I don't think it matters. Specifically, the return from the control valve to the tank, the return from the left drive motor to the main pump, and the other return to the tank. I used 3/8 2 wire hose, as I had ends for 3/8" hose to make it work. I think they were 1/4 or 5/16 stock, with JIC-6 ends. I replaced both case drain filters. Rinsed the tank, new tank cap, and fresh AW32 hydraulic fluid Got the aux hydraulics working. I did a lotta other work to the machine, but this is all that was done on this system. I'm wondering if the BICS valve is sticking, as the way the hydraulics seem to bang on and off is similar to what happens when the seat bar gets lifted accidentally when you're running the machine. Anything else it might be? I'm fxxxin stumped..

 

[Tazza]

So, after getting the machine back together and running, out has exhibited a problem that did not exist before the I swapped the valve for a rebuilt one. At several points after getting it running and working again, it has had very jumpy, jerky, loud lift and bucket hydraulics. At first I thought it must be some air in the system, and it would get better. But the problem seems to come and go. Today it was the worst it's been, and the arms and bucket locked up completely for a while. The whole job entailed: swapping the control valve and rebuilding it with a bobcat kit. I split the bics from it, and re sealed everything. Several new lines, a few I made with larger diameter hose than was stock. But, those were all return lines and I don't think it matters. Specifically, the return from the control valve to the tank, the return from the left drive motor to the main pump, and the other return to the tank. I used 3/8 2 wire hose, as I had ends for 3/8" hose to make it work. I think they were 1/4 or 5/16 stock, with JIC-6 ends. I replaced both case drain filters. Rinsed the tank, new tank cap, and fresh AW32 hydraulic fluid Got the aux hydraulics working. I did a lotta other work to the machine, but this is all that was done on this system. I'm wondering if the BICS valve is sticking, as the way the hydraulics seem to bang on and off is similar to what happens when the seat bar gets lifted accidentally when you're running the machine. Anything else it might be? I'm fxxxin stumped..

My first thought was the BICS lockout valve too. Did your other valve have the stem and coil? I'd swap the stem over and see how it goes.
The coils do fail over time, they can get hot and stop working, this would lock your lift hydraulics out.