splitter pump pulling a vacuum?

[Patrick62]

I was thinking about this the other night, and today I poked a vacuum gauge into the feed line of the pump, with some rather surprising results

this is the setup. Vacuum hose poked thru the hunk of radiator hose on the inlet of the pump (22gpm). Cheesy, but this is what happened (and is about to be changed out this winter) Splitter was origionally built by me around a 16 gpm pump, and I built the supply tank and iirc 1" hose. couple years later I upgraded to a 22 gpm pump and discovered that the inlet was larger. so I used a hunk of radiator hose to connect, and we have run it several years that way.

Last summer I was puzzled as to why it was running warmer than usual, and later on this fall I was noticing a reduction in speed. These thoughts tend to get stuck in mind, and eventually they get more thinking time. I am thinking the pump is okay. I can connect a pressure gauge to determine that, but it has plenty of pressure to push a block thru the wedge sideways!


Fired it up this morning, and engine running at 2400 rpm, outside temperature of 30 deg. Holy Cow. 7" of vacuum. I have been known to start this thing up on cold days and have it collapse the inlet hose before... puzzling as to why that didn't happen today... Okay, warm it up a bit, drove it over to a pile of blocks and split some up. 1/2 hour later I have noticed that it settled into a steady 5" reading. Busted up a few more, and for giggles Stuck a 9" limb in there sideways a cut it in half. This forced the pump into the high pressure/low volume stage. And the reading dropped to zero or very close to it. Busted up more blocks and it is now warmed to 80 deg, and the reading is now:

Just about 3" of vacuum...

My thinking is that I am going to build a new tank. I might be able to modify this one, but it might not be worth it. What I did was to weld in a pipe with about a thousand itty bitty holes drilled in it. If I can cut it out, and re-do it without blowing myself up.... might be better to start with a fresh tank, and make the inlet serviceable

 

[GM_Grimmy]

You need a strainer for your input line.

http://www.surpluscenter.com/Brands/Zinga/2-NPTM-TO-1-1-4-NPTF-23-GPM-TANK-STRAINER-9-7290-125.axd

One like that. A pipe with drilled holes in it is a bad idea. You can get a weldable bung to put in there, so you can screw the strainer in.......bam, serviceable.

I had my splitter out a week ago, to do some small stuff for my fire pit and even at 70-80 degrees oil temp, it was slow. I have a tank heater built into mine, but I wasn't going to plug it in overnight for 30 minutes of splitting. I like my oil 80+ before I start if I can help it.

 

[Patrick62]

Excellent idea. all I gotta do is get a flange welded on, and viola...
The vent hose kept getting clobbered with blocks for years and I am certain that there has to be some sawdust in the tank. I actually thought my tube with a bunch of holes fairly clever... but really only fine enough to filter the sawdust (mostly).

I am thinking that getting the correct size hose would help bunches. The 1" really was only sufficient for the 16 gpm pump... but, we have split hundreds of cords of wood since then with it.

 

[GM_Grimmy]

The inlet to my pump is just over 1" but I have a bigger hose going right up to it.

If you suspect saw dust, might be a good time to empty it, and clean it, and check. I'd suggest refilling it with new oil though. You can get a filler cap that has a breather built into it as well, or a screw in breather, that would be better to keep saw dust out. I would hope your filter would catch anything that might be in the oil. Might be time for a change of the filter as well.