asv pt 60 hydraulic problem

[stoneybrook]

Hi. I am having a drive issue with one of our machines its a 2008 asv pt 60 with a two speed hyd transmission. Looking for some advice. WE have checked all the basics, seat and lap bar switches. I have hooked up a gauge to check charge pressure. Asv says charge press should be a constant 400 psi. In low range while trying to travel ( empty bucket ) the pressure drops to around 300 psi. If I try to load the bucket with loose material it drops to zero psi and then the loader also looses all functions. after releasing the joystick to the neutral position the loader will operate again. The machine will move in all directions but very erratically all the time. It will not climb a hill without squealing and stalling. When using it in high range it maintained around 400 psi and this is how we have been trying to get it thru the busy season. However it is now beginning to do the same thing in high range. I am thinking it is the pump seeing how it looses press in all directions rather than a bad drive motor. I don't want to waste any more money on this machine without being positive. I have already replaced a $1300.00 posi relieve valve and a $ 500.00 joystick and all the spools and solenoids. Its a bosch Rexroth system and they don't give out any info on their products. Does anyone know if there is a seal kit for the hyd pump ? Any tips or advice would be appreciated. Thanks

 

[skidmarx]

i have the same machine and am trying to figure out the problem, mine sounds basically the same as yours, locks up on left side after a short distance , they say its the drive motor assumingly, after replacing hydraulic relief valve, still doing it, now in high speed also

 

[stoneybrook]

Skidmarx I tried e mailing you back but for some reason it would not deliver. Your problem does sound like a drive motor as only one track is locking up. What I'm trying to find out is whether the 2 speed is located in the pump or is it in each drive motor ? Both of my tracks are locking up under any resistance at all and then the loader loses all power. I spoke to a tech the other day and he said that it still works in high range because its more fluid at less pressure vs low range which is less fluid at a much higher pressure. So basically what ever is leaking back to case drain is still holding together at least under the lower pressure. Which does make since. Try loaderpartssource.com for the cheapest drive motors I could find. I'm not positive but I think its the same drive motors that are in the cat 247 and 257 models. I plan on tearing it apart as soon as we finish this job I will keep you posted. Let me know how you make out.

 

[sew350]