I just rebuilt, in a way, a hydraulic pump. It
had some issues lifting, figured I'd see what I
could do about it. I dropped the pump, took the
whole thing apart, blew out all the channels,
replaced the side chamber gaskets, ground down the
valves and seats. I did a really nice job.
Replaced the safety valve. I replaced the lift
piston earlier with the newer style.
Everything was going great. Went out to test the
system. Test one (about 200#) worked great for
the lift and lowering. Smooth and held great.
Thought I might trying something a little heavier,
before I started patting myself on the back too
hard.
As I was lifting the heavier item, something in
the pump went BOOM!! Much to my surprise, it was
the side of the chamber, at the top, just below
the plug, as listed in the exploded view in the
I&T manual.
I was shocked to say the least. I can replace the
side chamber, as I've got spares, but not that
many spares. I don't want to make the same
mistake twice.
I can't figure out a few things: a) why didn't my
new safety valve relieve the pressure before the
metal blew out? b) did I tighten the cap screw
too tight. I didn't find a torque value for that
cap screw, and I've had them leak in the past, so
I really bore down when I put this together. c)
could the side chamber have been stress before,
had a hairline crack or something like that.
I did remove this pump from a parts tractor I
have. It is actually a steel pump, not a cast
aluminum pump (which surprised me). There was
some water in the belly as expected, but not that
much water. This blow out was right where the
plug (part #3 in the exploded view) meets the
valve chamber. Which would have been much higher
than any water that was in the belly.
I'll drop the pump later, and get some pictures if
that will help. I appreciate your thoughts. This
really woke me up this morning when it happened.
Bill........
had some issues lifting, figured I'd see what I
could do about it. I dropped the pump, took the
whole thing apart, blew out all the channels,
replaced the side chamber gaskets, ground down the
valves and seats. I did a really nice job.
Replaced the safety valve. I replaced the lift
piston earlier with the newer style.
Everything was going great. Went out to test the
system. Test one (about 200#) worked great for
the lift and lowering. Smooth and held great.
Thought I might trying something a little heavier,
before I started patting myself on the back too
hard.
As I was lifting the heavier item, something in
the pump went BOOM!! Much to my surprise, it was
the side of the chamber, at the top, just below
the plug, as listed in the exploded view in the
I&T manual.
I was shocked to say the least. I can replace the
side chamber, as I've got spares, but not that
many spares. I don't want to make the same
mistake twice.
I can't figure out a few things: a) why didn't my
new safety valve relieve the pressure before the
metal blew out? b) did I tighten the cap screw
too tight. I didn't find a torque value for that
cap screw, and I've had them leak in the past, so
I really bore down when I put this together. c)
could the side chamber have been stress before,
had a hairline crack or something like that.
I did remove this pump from a parts tractor I
have. It is actually a steel pump, not a cast
aluminum pump (which surprised me). There was
some water in the belly as expected, but not that
much water. This blow out was right where the
plug (part #3 in the exploded view) meets the
valve chamber. Which would have been much higher
than any water that was in the belly.
I'll drop the pump later, and get some pictures if
that will help. I appreciate your thoughts. This
really woke me up this morning when it happened.
Bill........