volvo ec25 one track wont turn

[oggy307]

Hi first post from a newby! ive a volvo ec25 with a track problem. One track works perfect but the other tries to work but it seems like a pressure relief valve cuts in. if the track is off the floor it works perfect but wont move when on the ground. I am sure its a valve block problem as when i swap the pipes over the oposite track then dosent work. It cant be the main relief valve as everything else and 1 track work perfect. Is there a relief valve in each seperate valve of the block? would an O ring problem on the shaft through the valve cause this problem? its the same in forward and reverse. Any help or advice would be greatly appreciated thanks

[Muz]

Does it move at the same speed as the other one when jacked up ? Does the double speed travel work ok ? That machine has shock valves on the block too if I remember correctly

Welcome to the forum BTW

[oggy307]

hi thanks for your reply. ive had another coulple of hours on it today. does anyone know if theres some other balance valve somewhere under the machine to match the track speeds? ive swapped the pipes over with the next valve on the valve block (breaker pipes) and it does the same fault so i dont think its a main valve block problem. the four pipes from the valve block to the tracks disapear under the machine and I wondered if there was another valve somewhere underneath. Not sure about a double speed setting? im quite new to this machine.

[oggy307]

Ah yes found the double speed button! yes works on both speeds when track is in the air. Im sure its a pressure relief valve somewhere. dont think it has shock valves. does anyone know where i can find a hyraulic diagram on line without having to pay! thanks

[Muz]

Could be a rotary distributer problem, a seal break up or something. Theres no balance valve as such . Is it a cable operated connector to the valve block from the track levers, I take it youve checked they are clear and both levers pull on the same amount of travel ?

[oggy307]

yes there are cables to the valve block and are travelling correctly. Ive found one of the other rams on the arm is very weak as well. now looking into a relief valve. thanks

[Muz]

yes there are cables to the valve block and are travelling correctly. Ive found one of the other rams on the arm is very weak as well. now looking into a relief valve. thanks

Wouldnt be unusual ... could you give us a note of the correct pressure for that machine ?

I was asking about the double speed travel because its a solenoid that controls the flow, and Ive had bother with one before, where it increases the oil flow but reduces the tractive effort produced

I think there's 3 main reliefs on that block