4200xl old problems

[gmmiller06]

So I got this excavator back in early 2015 or 2016. I had a servo go bad which was giving me a lot of crazy feedback causing tracks to move, carriage rotation, etc. So I replaced the servo with a hitec. I haven't been able to get it to work right since. The booms barely move at all. I shelved it when my kid was born back in 2017 and I am just now getting it back out to try and fix. Now I have replaced all of the servos with hitecs, and I reversed the 4th servo prior to installing since I read Hitec servos run reverse from the tower pro's that were in it from rc4wd.

Is there a good way to check the 4th valve alignment? I have been thinking that was the issue but I have taken the servo out completely and even tried manually adjusting the 4th valve and I still cannot get the booms to raise no matter the position of the 4th valve. I am wondering if it is a pump issue now or if I am just not getting this 4th valve set correctly. I do hear the motor strain a little when trying to work the boom functions but nothing happens. If I push or pull on the arms of the excavator while working the functions the booms will move with assistance, but have no power at all.

Any ideas on getting this beast back to digging?