Log splitter will only split at low engine RPM

[nezwick]

kevin, that's one crazy story. Sounds like some of the things my brother used to be involved with (he worked for Brookville locomotive in PA).

Yep, the capped nipple at the rear of the tank is the fill for the gasoline (the tank is divided into two compartments).

I will have some free time this morning to dig into some of these issues. First, check for the presence of water in the tank and remove if needed. Second, check/clean the strainer. Third, try operating the splitter with the "vent" plug open to test for the vacuum condition.

And I'll try to take pictures along the way.

 

[kevin j]

And check the return connection and routing.

 

[jetsam]

This is the best splitter thread ever.

 

[VirginiaIron]

This is the best splitter thread ever.

I'll bite..., why?

 

[nezwick]

Well guys it rained here all morning and we had family stuff this afternoon so no splitter troubleshooting today... hopefully tomorrow!

 

[jetsam]

I'll bite..., why?

Why??

Homemade splitter, mystery being resolved, technical experts talking hydraulic bits... we also had a big explosion if all that's not enough for ya!

 

[VirginiaIron]

I'll agree. There are so many success stories on here and a lot of knowledgeable people in the forum who are eager to help someone. Plus the gear section is a smorgasbord of topics that will keep the participants engaged

 

[greg13]

In my 40+ years of doing hydraulic work I have never seen a suction line come out of the TOP of the tank, that right there is a major potential for problems. You are relying 100% on the pump being able to pull fluid to it. I would add a port to the bottom of the tank to supply the pump and let gravity do the work.

Think back to when you were a kid and you tried to drink soda through a straw with a crack in it, if you got any it was more foam than liquid. The pump will be the same way.If you have ANY type of leak on the suction side the way it is plumbed you will have the same results.

 

[VirginiaIron]

Yes, that suction line is doing an alioop and would be better sailing under the beam to the pump. This way the fluid level is already above the pump.

 

[Jags]

I am interested in the definitive answer to whether we are dealing with water or air (possibly both). And I really don’t like the idea of a closed loop hydro system on this thing. The in/out of the cylinder WILL create a suction/pressure environment with the volume difference being the the cylinder shaft.

 

[rox3406]

Water does not “settle “ out of hydro oil over night. Once it’s milk it’s mlik. If it clears up over night it’s air. Plain and simple. Deal with this sort of issue all the time.

 

[greg13]

I am interested in the definitive answer to whether we are dealing with water or air (possibly both). And I really don’t like the idea of a closed loop hydro system on this thing. The in/out of the cylinder WILL create a suction/pressure environment with the volume difference being the the cylinder shaft.

I agree, there needs to be some type of vent, even if you thread a pipe nipple into the tank and screw an oil filter on it. I have seen that done many times and it does work well.

 

[zrock]

I may have missed it but the oil / fuel is the same tank but separate. Have u checked the oil for fuel contamination? Their may be a pinhole that sucks fuel in when oil tank is creating a vacume

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[VirginiaIron]

I am interested in the definitive answer to whether we are dealing with water or air (possibly both). And I really don’t like the idea of a closed loop hydro system on this thing. The in/out of the cylinder WILL create a suction/pressure environment with the volume difference being the the cylinder shaft.

I think that suction due to shaft size is minimal until the pressure increases due to the temperature increase. I

I may have missed it but the oil / fuel is the same tank but separate. Have u checked the oil for fuel contamination? Their may be a pinhole that sucks fuel in when oil tank is creating a vacume

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Greatt point. I thought about addressing that but all the fuel contaminated oil I have seen just looks thin and smells like gas or diesel fuel.

 

[VirginiaIron]

I may have missed it but the oil / fuel is the same tank but separate. Have u checked the oil for fuel contamination? Their may be a pinhole that sucks fuel in when oil tank is creating a vacume

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I have given this more thought. What if, since the commission of that vessel, water has accumulated on the lower third of the fuel tank an now that portion of the lower tank has deteriorated and has a tiny perforation?

 

[zrock]

good possibility

 

[nezwick]

Wow everybody, sorry I've been a bit absent. I do have a couple of answers to the last set of questions that were asked.

1. Here is a picture of the fluid (after sitting for days, covered by a tarp). It looks almost just like it did the first time... Hmm. The picture also answers the question about the orientation and depth of the suction strainer. According to what you said, it appears to be set up correctly. The strainer was not clogged but I put it back in the solvent bath for overnight just for good measure.

2. There is a stand pipe on the return line inside the tank. It goes almost down to the bottom of the tank. I just didn't notice it before. So, that also sounds like it's set up correctly.

3. On the topic of the bottom of the tank rusted from the water, it was really nice and shiny underneath the layer of gunk I wiped out of it. The tank is very thick steel. Hopefully that makes the rusted pin hole less likely of a problem.

4. Another clue that might help the troubleshooting effort is this. Before I did any of the disassembly pictured above, I for some reason decided to run the control lever back and forth (engine off) to see what would happen. I heard a pretty distinct "hissing" noise coming out of the fitting where the suction line connects to the nipple at the top of that plate. I grabbed a pipe wrench to tighten it, thinking the connection was loose, but everything was nice and tight. Does there need to be pipe dope or teflon tape on the suction side fittings to seal them? Because there is none. Of course, this is all going to be re-done in the event of re-routing the suction line to the bottom of the tank anyway. But a hissing noise to me would indicate a pretty bad air leak.

 

[nezwick]

Also, the fluid does not smell like gas.

 

[VirginiaIron]

That supply pipe from the filter appears to be 1/2 inch ID pipe and the hose appears to the pump appears to be a 1" size. Does your pump require 3/4 or 1" pump inlet supply? If the supply side is too small the pump may cavitate and would explain why it only has force on low rpm. Does the pump make noise?

 

[VirginiaIron]

What is this fitting?

 

[nezwick]

I just measured the ID of that pipe - it is 1".

That other fitting has a small hose connected to it, which also runs to the hydraulic pump. I had to unhook it in order to get the cover off. I'm not sure of its function though.

 

[nezwick]

If you look back at the picture of the overall machine a couple posts up, you can see how the small hose runs between the pump and tank.

I've been looking at log splitter hydraulic diagrams on the internet and have not come across any that include the extra hose that mine has. Could it be that the pump has some sort of internal pressure relief or regulator that will just dump out that hose if needed? For example, this diagram has a separate standalone relief valve that connects to the return side plumbing. In my case, it terminates directly at the tank.

There is a spot for a pressure gauge in the steel high pressure line that runs between the pump and control valve. I'll have to get one of those when I'm out and about tomorrow.

The more I study the diagrams and start to understand the system, the more I definitely see the advantage to moving the suction pipe to the bottom/side of the tank instead of down through the top.

 

[rox3406]

The small hose could be a case drain. Bleeds off any internal case pressure from leakage internally in the pump. If the guy that built that unit took the pump off an old piece of equipment then a case drain wouldn’t be in common. Never see one on any newer splitters though.

 

[nezwick]

Got it. No question in my mind the pump was re-purposed from some older piece of equipment. Who knows what.

It also does appear that there should be pipe dope on all of my NPT connections. I can think of quite a few that might need inspected. I bet the air leak I was hearing was coming from where the hose screws onto the nipple. That's an NPT fitting, and there was no tape/dope present. I can definitely see there being lots of air drawn in through there when the system was in operation.

I also understand no sealant is to be used on the JIC fittings.

 

[Ashful]

Got it. No question in my mind the pump was re-purposed from some older piece of equipment. Who knows what.

It also does appear that there should be pipe dope on all of my NPT connections. I can think of quite a few that might need inspected. I bet the air leak I was hearing was coming from where the hose screws onto the nipple. That's an NPT fitting, and there was no tape/dope present. I can definitely see there being lots of air drawn in through there when the system was in operation.

I also understand no sealant is to be used on the JIC fittings.

This is correct. Also, if using dope, make sure it's rated for hydraulics, as most aren't.