Testing hydraulics..then a BANG

[Dan S (NY)]

Finally got all the lift arms together on the 1964 MF50 and was testing the hydraulics. I was standing on the carryall platform to add some weight and a friend of mine was lifting me up and down to test the system. Everything was working great for a while, then when I was near the fully raised position there was a Bang and I dropped to the ground. Pulled the top cover today and found lots of cracks in the cylinder so the problem is obvious, but what was the cause? I don’t want a new cylinder to suffer the same fate. This top cover had a crack that was welded up and that weld seems to be holding fine. I have run a straight edge over all the mounting points for the cylinder and everything seems flat. I had torqued all the nuts on the cylinder and all the bolts on the top cover by the book when this was put back together. We had gone through the control linkage adjustments before assembly, but now wonder if something wasn’t adjusted correctly??? Could that have caused this and wouldn’t the relief valve have prevented such a thing from happening? I didn’t hear the pump laboring hard or anything. Any thoughts are welcome. I don’t want to break another one!

Thanks in advance.

Dan

 

[Dan S (NY)]

Picture of cylinder removed.

 

[dhamps10]

Just a thought, could a bolt have bottomed out, causing stress?
 

[Gearhead210]

I would check 2 things first:

1) Make sure that the pressure relief valve is working- although this breakage is still possible with a properly functioning relief valve.

2) Make sure that the quadrant controls (lift controls) are adjusted properly. If they are not, the cylinder can bottom out and the valve will be in "constant pumping" as they refer to it on the newer models.

The pressure relief valve is just ahead of the side cover on the "dipstick" side of the transmission- if it is still full of oil you will have to drain 4-5 gallons out to see it. They aren't that expensive, and I would replace it if it were mine.

I do not know the steps for checking the adjustments of the quadrant controls off the top of my head, but if you own or have access to an I&T manual, they do a pretty good job. An MF service manual will go into a little more detail.

Hope this helps
 

[trac]

WOW never have i seen such a thing No i don't think the relief vavle is working properly.I'm sure you'll get some words of wisdom on this
 

[Dan S (NY)]

The cylinder is held in by studs and fine thread nuts outside the top cover so you can't really bottom anything out on those. I don't think any of the top cover bolts did either but its something I will pay attention to. Thanks for the suggestion.

Dan
 

[Dan S (NY)]

Yes, I was planning on replacing the relief valve just to be sure. I will definitely be reading up on the adjustment procedures again!

Thanks,
Dan
 

[Jerry/MT]

It looks like there was some some side force applied on the cylinder. Is the rock shaft loose on one side or not centered properly?
 

[trac]

Looking at the first pic. again it shows wear marks on ram arm almost like it is off center like someone said before.What would cause that piston rings not in right?Now that you have it off what do you see?
 

[Dan S (NY)]

I was never able to get the lift arms off so I never removed the rockshaft. It didn't seem off center and I don't think the bushings eeemed to loose. I will check tonight to see if one side seems looser than the other.

Thanks,
Dan
 

[Dan S (NY)]

I will have a closer look tonight. I didn't really notice anything about the ram arm when I was taking it apart, but then again the cylinder was my main focus at the time.

Dan
 

[JMOR]

[Dan S (NY)]

I have been thinking along those lines as well. Because this cover has a welded crack I was wondering if there might be a slight deformation between the individual cylinder mounting points. I will see what I find when the new cylinder arrives.

Dan
 

[Dan S (NY)]

Here is a picture of the ram arm directly from the front. The rockshaft isn't loose. I can see a mark on the back side of the ram arm that would indicate the lift was topping out though. When the new cylinder arrives I will check it sits square and flush on the cover and be very carefull with the linkage adjustments.

Dan

 

[Shane Tharp]

About a year ago, mine did basically the same thing. The problem was ice froze up the pressure relief valve and the cylinder broke into two pieces. I looked on the inside of the cylinder and it was worn out also.