wdchyd
Elite Member
They're gonna need the whole splitter, easier to put flow/meter inline than to mount the pump on a test stand (which most repair shops do not have)
No cylindder pressure....
- Thread starter mrcaptainbob
- Start date
- Views: 6436
They're gonna need the whole splitter, easier to put flow/meter inline than to mount the pump on a test stand (which most repair shops do not have)
J_J
Super Star Member
- Joined
- Sep 6, 2003
- Messages
- 18,952
- Location
- JACKSONVILLE, FL
- Tractor
- Power-Trac 1445, KUBOTA B-9200HST
What is the HP on your log splitter engine?
Is this a factory or home made splitter?
Is this a factory or home made splitter?
OP
mrcaptainbob
Platinum Member
It's a home made splitter, J-J. And, from what I understand, the neighbor that owns (now deceased...) is/was the third owner and has had it for about six years. A month or so ago it needed a head gasket. I was told it was a ten horse Briggs. Glad I brought the old gasket for a match up, as it turned out to be a Tecumseh! It still may be a ten horse, though!
OP
mrcaptainbob
Platinum Member
Moved the cylinder to center and checked for any internal bypass. It's good. The pump is now on the bench with both ends off. Under the inlet end there were six balls, each covered by a light duty spring. Nothing broken there. No obvious signs of pitting. The ports the balls lay in appear to be screw inserts. The casting is lightly punched two sides at each insert. Each insert has two large slots assume are used for unscrewing. On the mounting end there's a seal in that casting. Removing it and there was a shim on a ball bearing. That's as far as I got before I start damaging stuff. My question is how to remove the shaft and bearing. There is a center hole at the inlet end of the pump where it appears I could punch the shaft. But only if it has a shoulder that the ball bearing at the other end rests on. Looking for guidance on this. Once the bearing comes out, what guts should I expect? Lots of small spring loaded bearings? Fins? Should I lightly tap the far end of that shaft?
OP
mrcaptainbob
Platinum Member
Took the pump apart. It's a piston with swash plate type. The six pistons are very smooth in the cylinders with absolutely no side movement. I mic'd the polished used part with the unused surfaces and there is no difference in diameters. The springs are all equal length. Nothing seems out of sorts. Except....at the port end there are two 'O' rings. One around the input port and the other at the casting perimeter. Both seem to be less than 'supple'. And flat. Could it be that pressure was leaking past a weak seal? I presume it should be an 'O' cross section and fits in a square slot. I'll take the end plate and 'O' rings to a local hydraulics shop and maybe they can match them up. Anxious to see if this solves the problem....
oldnslo
Super Member
Captain,
On the six balls, do some of them connect to the suction or inlet port and the others to the pressure port or are they all common to one port? It almost sounds like you are describing a check ball style pump.
If this link works it is an example of a Dynex check ball pump.
High Pressure Pumps for Hydraulic Systems
On the six balls, do some of them connect to the suction or inlet port and the others to the pressure port or are they all common to one port? It almost sounds like you are describing a check ball style pump.
If this link works it is an example of a Dynex check ball pump.
High Pressure Pumps for Hydraulic Systems
OP
mrcaptainbob
Platinum Member
That's it, Oldnslo. Except the intake is on center on the end and is sucked in through the sidewalls of the cylinders similar to a two cycle. But it compresses and does eject through the check balls at the end of the cylinder. Since it would allow oil to drain from the tank through the pressure port, I assume it can only mean that either the center seal is allowing bypass or the check ball springs need replacing. Come Monday I will try to scare up new seals and try for new springs, too.
oldnslo
Super Member
Captain,
In theory the pressure should seat the check balls. I have limited working knowledge on this style pump so i would only be guessing on what would cause it fail. Possible only one or two of the pistons are pumping properly which would allow pressure buildup with the needle valve but add any leakage from a spool valve and it may all be lost.
Best of luck on the rebuild.
In theory the pressure should seat the check balls. I have limited working knowledge on this style pump so i would only be guessing on what would cause it fail. Possible only one or two of the pistons are pumping properly which would allow pressure buildup with the needle valve but add any leakage from a spool valve and it may all be lost.
Best of luck on the rebuild.
OP
mrcaptainbob
Platinum Member
Eureka!! I purchased the two 'O' rings and found that they should be circular in cross section and not square. But while reassembling it I found two of the six check ball springs to be shorter than the others by two coils! While the 'good' ones were flat and tapered at the spring ends, these two were obviously cracked off, as the wire was flat at it's tip. Easy to see comparing the two ends. It does appear that this would allow for the slow but constant dripping of the reservoir through the pump, and would also point to the low pump pressure. And may also point to the high reading when using that gate valve. High pressure, but low volume. So, I need to get six new ones. Six springs with six coils at .025 wire diameter x .40 high x .30 diameter. Where can I get stuff like that? Would a hydraulic shop sell me something like that?
oldnslo
Super Member
A good hard ware store may have some or possibly McMaster Carr. I doubt a hydraulic shop would have them but possible.
