While moweing today, I noticed for just a few minuets that I was haveing to push a bit further on the sticks. Then, during my turn I really felt something a miss.
Although I have done repairs on the right side pump recently, the left side seems to be acting up also. It kind of feels like the pumps are not getting fluid. belt is tight, dump valves were cllosed and it's full of fluid.
I would remove the filter and cut it open to check for metal and other unwanted particles. Also there may be a screen in the suction line(s) to the pumps from the reservoir, check the screens. When you remove the return oil filter, the oil in the reservoir will drain out thru the oil filter adapter so be prepared for this. Let the oil drain and check it for foreign particles. Hydraulic drive oil is 20W-50 engine oil more than likely.
Let us know what you find.
Mad Mackie in CT
Is the oil in the reservoir as bad? This filter is there to capture this stuff in the return flow from the pumps/wheel motors.
Either the system wasn't fully flushed or there is another failure of a system component.
Mad Mackie in CT
Put on a new filter, refill the system and give it a try. But before you refill the reservoir look inside to see if there is/are screens on the suction fitting/s and if they have any foreign material stuck in the them. Most hydraulic systems of this type have some sort of filter screen installed in the suction to filter out the big chunks from getting sucked into the pumps.
In the parts manuals I see no reference to any screen filter as a separate part. However it may be soldered into the suction fitting and listed as a Scag assembly part number.
Anyway, put on a new filter, fill the system and run it. At this point in time any major component damage if any has already happened.
Mad Mackie in CT
Picked up my filter and oil today. Was told to take lines loose to wheel motors and flush witj diesel . Also he said if the diesdl is not a steady stream when you turn the hub the wheel motor is bad. Ever heard anything like that?
Yes I have heard of doing this. Both hoses to the wheel motors need to be disconnected from the pump. You may be able to utilize the hoses from the pump to the motor by disconnecting them from the pump and the motor and reposition them out from the motor so they can be put into a container that diesel fuel can be poured into and have the end of each hose below the level of the diesel fuel. You will need to jack up the machine and remove the wheel to do this. Turning the wheel motor will cause it to act like a pump and it will suck up the diesel fuel thru one of the hoses and push it out the other hose. Changing direction of the wheel motor will reverse the flow of the diesel fuel thru the motor. When you determine which hose is the suction then you can lift the other hose out of the diesel fuel and watch the flow out as you turn the wheel motor. Potentially a messy job.:frown::frown:
If the hydraulic hoses are not cooperative enough to do this you may be able to use clear vinyl hose and push it onto the male fittings on the wheel motor and then into a container.
You will need to remove as much diesel fuel as possible from the motor and hoses before reconnecting the system as it will mix into the hydraulic system and thin the oil.
Have fun!!:laughing:
Mad Mackie in CT:biggrin::smile::laughing:
Looks like I dodged another bullet. I did have to roposition the hoses and there was a lot of gunk that came out of both motors. After filling with fluid I started mower, ran controls and all seems well. I was thinking about changing filter and fluid again in about 10 hours or so just to make sure the system is clean.
Here we go again. Today, I thought I would give the mower a good test run. However, after about 45 min or so it started to loose power to the right. I continued to mow for abot 5 more min but it kept getting worse. now im stumped again. I am going to check it in the morning to see if it works when its cool.
Took my left pump off today and when I opened it up to check the piston pac it is obvious it has had a bearing failure. There is also metal shavings in it and the area the bearing sets in is pretty scarred. As I have mentioned earlier in this post, I am experiencing problems with both sides. whats my next move?
Hi Jeff,
This doesn't sound very good!! I suspect that cross contamination has happened from the R/H pump failure. No doubt very frustrating for you.
You are probably looking at new pumps and wheel motors on both sides, and dissassembly and cleaning of the entire hydraulic system. Metal particles have a way of hiding in spots that a system flushing would not clear out.
This job will probably cost more than the machine is worth in proper working order, so you need to do a rough estimate and then decide what you want to do.
Mad Mackie in CT
Yeah, I am kind of worried about that also. When I cleaned out the wheel motors the right side was very tight and hard to turn while the left felt smooth and fairly easy. I gues I will start with this pump and see what happens.
The R/H wheel motor has a problem if it turned with difficulty when you flushed it.
There is no doubt in my mind that the entire hydraulic system is contaminated. With a common reservoir supplying both pumps and a common return back to the reservoir from both pumps there is no way of preventing cross contamination. I think that the return filters have bypass valves and when the filtering element gets plugged enough then it goes into bypass which passes unfiltered oil back to the reservoir.
As an aircraft mech I have replaced engines that had only a scavenge oil pump failure and the oil supply tank, oil cooler, thermostat valve assembly, oil shutoff valve, and all hoses had to be replaced just as if the engine had a major internal failure. The scavenge oil pump is used in a dry sump type engine to pump expended engine oil thru the oil cooler and back to the oil supply tank.
Mad Mackie in CT
Purchased new left side pump and had the right side pump checked out by a local dealer. Also had right side wheel motor checked and to my surprise the dealer said it looked fine. Removed and Had entire hydro system flushed. Going to put it all back together Monday.
Any hints on how to purge system, or do I just hook up hoses fill tank and fire it up.
I would jack up the rear on the machine and put blocks under the frame behind the rear wheels.
The system is probably totally empty and I would fill the reservoir full, and start the engine and add oil as the reservoir empties. Release the parking brake and carefully cycle each direction lever as you monitor and add oil to the reservoir until the level stabilizes and the wheels turn and respond to the direction lever input.
Ask the dealer if they have any suggestions for refilling the system as my above mentioned method may not be the recommended way, these are just my thoughts.
Mad Mackie in CT
Ok, update timr. I have replaced both pumps and the right side wheel motor. All seems to be working ok, but feels a little weak on a hill. The looks like it has alot of air bubbles. also, I have a leak that I am haveing a hard time finding. Is it normal for the oil to look like that? Coukd the system be getting air and causing it to feel weak?
I suspect that because of the way the pump and wheel motor units are designed that it will take a while to bleed the air out. Basically the pump circulates oil thru the wheel motor to varying degrees and direction, the reservoir provided a liquid level above the pumps and a place for the return oil to flow to thru the filter. You need to make sure that there are no leaks particularly in the pump suction lines to the reservoir. Have fun!!
