574 Brakes and steering problems

[Clark]

I"ve got a 574 diesel that has been a real workhorse but late last summer the brakes and steering started going south on me. The steering is usually good but other times you can spin the wheel around and around and barely move the wheels. The brakes usually start out fairly good but after the tractor warms up you have to pump them a time or two and then it gets progressively worse to the point that the pedals will go all the way down and barely slow the tractor. Needless to say I can"t keep using it like this so I need some help.I was told that the brakes and steering are part of the main hydraulic systems and to change the hydraulic fluid and filter which I did (even though I do that regularly anyway) and that didn"t help. I was told to take out the diverter valve and make sure that it wasn"t sticking and that all the O-rings were good so I did that and still no lick. My understanding was that the diverter valve only provided fluid for the steering so I don"t think this would have solved my brake problems but it was worth a shot. I feel sure that the hydraulic pump is fine because the lift and PTO both work great and have as long as I have had the tractor. Does anyone have any other ideas that may help?

Thanks!

Clark

 

[FromJB2]

Hi Clark, you are correct there is a flow divider in the MCV valve that splits the 9 GPM output of the hydraulic pump into 3 GPM for PS and PB and 6 GPM for 3pt and remotes.
The brakes are supplied by hydraulic oil from the return side of the hydraulic oil cooler in front of the rad. The brakes are also a dead end circuit so any air that gets in the brake system stays there until the brakes are bled.
Re your problem, try activating the remote control valve until your hear the relief valve squeal. Sometimes this will dislodge dirt stuck in one of the MCV valves.
If the above dosen't cure the problem then it is time for diagnostics with hydraulic flow and pressure guages to determine if it is a weak pump or MCV valve problem.

JimB

 

[Kippster]

we had a 574 gas on the farm and the darn thing always had issues with the brakes. I was the one who ran it the most and I usually just used one brake, otherwise the pedals would go all the way to the floor and not do anything. bleeding the brakes helped for about 4 hours and then back to the way it was. Using one brake was tricky, but at least it worked. As far as your steering goes, I would check the output on the cooler with a pressure guage and then also check the flow and pressure at the ports on the steering cylinder. Also, check the packing in the steering cylinder, we did have to replace that once, if I remember right. A pretty simple deal really. Just keep everything super clean.