JD 401C Hydraulic chatter

[snknby123]

Hello,

1st time poster here and looking for some advice. I purchased this 401C with front end loader about a year ago. Currently everything is operating and has plenty of power but I have a heavy chatter when I first engage the loader or boom. After the initial engagement it is not so loud but is still there. Removing the foot panels under the brake levers I have isolated to what I think is the pressure control valve. I can feel the chatter in the line going from the pressure control valve to the front pump.

2nd problem I have is the brakes, once depressed do not return to the neutral position. In otehr words they stay depressed and need to be manually disengaged. I have noticed a leak on the brake housing so I cleaned it up so I can find exactly where it's coming from. I bled the brakes per the manual but it did not help.

What I have done so far after I purchased the tractor.

changed engine oil and filter
flushed hydraulic oil (had water in it) and changed trans filter
changed loader hydraulic filter
cleaned out hydraulic oil cooler and radiator from the front with high pressure hose. After bush hogging about 5 acres the trans oil seemed way to hot to me.
bled brakes


I have read about a trans pump screen but with my configuration (loader filter) I can't seem to locate where it is? Thanks for any help you can provide.:thumbsup:

 

[jd110]

Welcome to the forum! Your label for the sump screen is correct. A pain to get to with the loader filter. I would recommend checking that first to rule out a problem there. Trans oil will need to be drained to remove. The pulsating line is the main pressure line from the pump. THat usually pulsates due to a lack of sufficient oil supplied from the transmission pump from clogged screen, filter or internal leak in rockshaft, steering, filter relief valve or weak transmission pump. Could also have a problem with main pump. A failed inlet valve, outlet valve or a stuck piston can cause this also.

 

[snknby123]

Thanks so much for your input.
Some more questions if you don't mind:

Once I put everything back together is there a procedure for purging the air out of the hydraulic system/lines? I can't seem to find anything in my manual.

If I use some type of screen over a 5 gallon bucket can I reuse the fluid or is that bad Ju Ju? thanks again

 

[jd110]

Just be sure to cycle all functions multiple times to purge out air. As long as you are careful to keep dirt out of the oil, I would use it over if it is in good condition. I usually try to save the oil drained from drain plugs, since you can usually do that cleanly. Other oil you catch from filter removal or line disconnects I would discard. Too much chance of dirt getting in oil during those procedures. It does help to clean the underside of the tractor with a pressure washer before you start to help keep things clean.

 

[snknby123]

Update:

I got the loader filter Assy. removed and pulled out the sump screen. Unfortunately, it was clean. Now I'm looking at the pressure control valve while I have this thing drained and torn down but I can't seem to get the control valve out of the end of the housing. I stick my finger in the end and try and slide it out but it just stops. Sliding it in and out I do feel a little resistance at one point.

Any tricks on getting this thing out? Does the whole Assy. need to be off before it comes out? I tried to remove the complete pressure control valve housing off the side of the tranny but the stainless steel connector is rusted tight. Lines are drained, can I use some heat or is that a no no?

Spring measures a little short from what the manual says but there are two washers or shims that bring it pretty close. It doesn't look like the washers or "shims" were installed at each end of the spring like the diagram shows. Doubt it matters. I want to check this aperture or orifice to make sure it's not clogged.