Control Valve Spool popping on 853

Help Support SkidSteer Forum:

Rambler

Member
Joined
Jul 29, 2020
Messages
20
I replaced the Seals on both Spools and as you can see in the video one of them seeming to be popping or binding. Not sure if it has always done this. I did use the old rubber boots since they were in good shape. Is the linkage pushing the spool into the control valve to far and I just need to adjust the linkage? I appreciate the help!
 

Attachments

  • Video.MOV
    14.8 MB
Where were you a week ago when I needed a picture of that lever that connects the spool to the left pedal mechanism? The prior owner took mine out for repairs at one point and neglected to toss it back in when they threw in the towel. I ended up using the graphic from the parts manual and a protractor to guesstimate the angles.

2F3FAED7-0593-495C-9737-F07A95015578.jpeg


Back to your question, the first thing I noticed in your video is that the connection from the lever to the spool is missing the second metal link. That's likely not causing the pop issue, but it will stop that twisting angle of the cotter pins you see in the video.

IMG_4746.jpeg


Have you fully purged the air out of the system after the spool seal replacement? I ask because that final pop may be air pressure acting on the spool. As a check point, if you pull the spool out, does the pop happen the opposite direction as well?

Make sure it's not the linkage causing the issue. Try disconnecting the cross lever from the spool and then see if moving the pedal causes any jerking motion at the same point of travel.

Finally, see the below thread on BTI374 regarding the spool seals to see if everything in there lines up with the rebuild you just did.

 
Thank you for the reply. The one link was off since I had been testing it with and without the two links connected to the spool. The spool makes the pop with one or both links attached. Also it only pops when the linkage is attached and the spool is push in. If I disconnect the linkage and push the spool in with a screw driver it does not pop. I have disconnected the cross lever from the spool and there is no jerking motion when using the pedals, I did use the correct seal per the Bobcat Bulletin.. Regarding purging air, I refilled the Hydraulic tank, let it sit overnight, then started it and let it run for 15 minutes. At start some grinding, but it disappeared. This is stumping me.
 
Last edited:
If the spool doesn't pop when the linkage is disconnected, then it's clearly your linkage, and from your testing, only when the linkage has resistance. Something (obviously) is loose, worn out (check the pivot bushing and related hardware) or misadjusted in the linkage. Don't forget the pedal itself. When I reassembled my linkage, my pedal needed to be moved forward a little bit because when I tried to pivot the pedal, it was catching on the frame piece to which it was bolted.
 
Top