T200 charge pressure low

[Cab4320]

Hello I’m new here I’ve got a2001 t200 pulled it in the shop to change a bottom roller on the right side while I had it down I replaced the seals on the boom control valve spools and a drive hose that just had a rubbed place on it “ not leaking” now when I start my machine the brakes are trying to lock down due to low charge pressure I rigged a manual gauge up and I’m showing 315 psi at startup and 250 2 mins later I know crazy things happen but it’s hard to belive my pump went out just sitting there so would anyone know were I could check pressure directly from the charge pump a hose or fitting location ? I want to eliminate pressure bypass in a valve before I rebuild the hydrostat unit

 

[walio123]

The machine uses a charge pressure from the gear pum. After making the seals on the boom valve ... it is possible to exchange hoses. The gear pump return hose goes to the charging pressure of the hydrostatic pumps. Look for exchanged hoses

 

[Cab4320]

The machine uses a charge pressure from the gear pum. After making the seals on the boom valve ... it is possible to exchange hoses. The gear pump return hose goes to the charging pressure of the hydrostatic pumps. Look for exchanged hoses

I have checked that. But will check again thanks for your input. Also you say charge pressure comes outa the gear pump on the right side. I get conflicting info on this. Some say charge pressure is delivered from a pump inside the hydrostat unit. Does it vary by machine model ? Clearing this up would really help me trouble shoot my problem

 

[walio123]

My English is not very good.By returning gear pump line I understand the hose that comes out of the main hydraulic valve and goes to the hydraulic filter. Somewhere there should be a tee that goes to the hydrostatic pump. After you have not touched the hydrostatic pump, I do not believe it has been damaged just by sitting . It is possible svaped hoses or possiblle that you do not properly assemble the valve and that its center is not fully open. Does the hydraulic system work correctly now / the bucket, the boom, the aux/ ? It is also possible for the hydrostatic pump to have an autonomous charge pressure But I still do not believe it has been damaged by sitting. I can send you hydraulic diagram tomorrow if you want, i can not check it today, to be shure is there autonomus charge pressure.I will check tomorrow.

 

[Cab4320]

My English is not very good.By returning gear pump line I understand the hose that comes out of the main hydraulic valve and goes to the hydraulic filter. Somewhere there should be a tee that goes to the hydrostatic pump. After you have not touched the hydrostatic pump, I do not believe it has been damaged just by sitting . It is possible svaped hoses or possiblle that you do not properly assemble the valve and that its center is not fully open. Does the hydraulic system work correctly now / the bucket, the boom, the aux/ ? It is also possible for the hydrostatic pump to have an autonomous charge pressure But I still do not believe it has been damaged by sitting. I can send you hydraulic diagram tomorrow if you want, i can not check it today, to be shure is there autonomus charge pressure.I will check tomorrow.

Yes. All lift functions work properly as for swapped hoses I’ve checked and belive all to be right I don’t have a hose diagram if you do have one I would greatly appreciate if you’d share it

 

[walio123]

Yes. All lift functions work properly as for swapped hoses I’ve checked and belive all to be right I don’t have a hose diagram if you do have one I would greatly appreciate if you’d share it

It is possible that the hydraulic filter is clogged. Check the hydromotors case drain filters for chips in them, this can give you a pretty good idea of what's going on. Where do you hang the pressure gauge to measure the charging pressure? I can certainly say your machine uses charging pressure from the gear pump. If it is a single section, the charging pressure is taken from the return filter line, check the hose not to leak anywhere or to clog. If it has two sections, the second is for the charging pressure. The hose must go to the hydrostatic pump. Here's a pretty good explanation of how to measure the pressure.https://www.youtube.com/watch?v=vDCM0RbiFZ4 Are there codes for low charging pressure? You may have a problem with the brakes themselves too. I just do not believe it was possible there was everything wrong before you did the repair, right? Write an email to [email protected] to send you a hydraulic diagram, I do not know how to get it here.