2 stage pump question

[isaaccarlson]

Hope no one minds me butting in here... Got a 2 stage pump issue as well.

I just put a new Haldex 16gpm pump from Northern Tool on my splitter with a 4x2x24 ram. Initial cycles without splitting a log were impressive over the old11 GPM pump. Well after I split the first log it is constantly in the second stage. The piston moves very slowly now.

Oil is filled to within an inch of the top of the tank. Breather is a steel cap with two holes in it and they are not clogged. The intake hose is tight. The oil filter only has about an hour on it now. Power to the ram is not the issue so things are working. Old pump would stall out and squeal like a stuck pig with some of the crotches this new pump is pushing through.
Just don't have a first stage for some reason.

I wondered if the control lever could be restricting flow for the 16 GPM pump. The old pump was only an 11gpm. The restriction might be pushing the pump into the second stage. I adjusted the unloading valve all the way in to increase the pressure needed to kick into the second stage. No luck there so I doubt this is the problem.

Only other thing I can think of is the oil is too thick. I got ISO 46 hydro oil. Would a ATF transmission oil be "lighter" than the hydro? Could this be the issue?
Northern Tool offered to exchange it but if I can fix it I would rather go that route.

do you have a gauge? what does it say? without a log?

 

[HD-tech-NH]

Thanks!

 

[CWME]

I don't have a guage on the splitter. If I get one where in the system should it go?

 

[isaaccarlson]

I use AW 32 hydraulic fluid from fleet farm. (10 weight)

put it between the pump and valve.

 

[CWME]

I will see if I can get one tomorrow. This will give me an idea if the valve is causing a restriction so I know if that needs to be replaced, right?

 

[isaaccarlson]

take out your switchover and see of it is ok.....might be stuck/broken spring.

 

[isaaccarlson]

I will see if I can get one tomorrow. This will give me an idea if the valve is causing a restriction so I know if that needs to be replaced, right?

I don't think it is going to be that choked off.....you should get a gauge though. It is VERY GOOD to have one. They let you diagnose problems in a heartbeat and help you set it up right. I am betting on your switchover. COULD be a bad spool but I doubt it.

 

[isaaccarlson]

The gauge will tell you if you have ANY restriction at all. Mine reads 0 when not cycling without a log. If I hit the end the second stage kicks in and the relief pops off at 2100 lbs.

 

[CWME]

I will pull it out in the morning to see if the spring is broken. Really sounds like the pump is bad.

Thanks for all the info!

 

[triptester]

Let me try to explain how a 2-stage pump works. It is actually two pumps in one housing, a low volume / high pressure section which pumps fluid all the time and a high volume / low pressure section that bypasses between 600 - 900 psi. If the bypass setting is too low the cylinder will move slowing almost immediately after contacting the wood but not stop completely. If the bypass setting is set too high the engine will stall.

If the wedge does not move and the engine does not stall the relief in the control valve is set too low. What the pressure setting of the relief is depends on the pressure rating of the high pressure components of the system. Normal factory settings are between 2250 and 2750 psi. The location of the relief adjustment in the control valve will vary depending on manufacturer.

A guage in the line between pump and control valve is needed to make these adjustments. The guage can also help in determining other system problems.

 

[CWME]

I pulled out the switch over and everything looks fine. No carnage in there at all. The spring was intact and everything came out without any resistance. Oil came pouring out of the hole.

I drained the system and put in an Automatic Tranny oil instead of the ISO 46 oil. The ATF is noticeably lighter. However no change.

I e-mailed Northern and they are going to exchange the pump for me.

 

[isaaccarlson]

could be a sheared key in the pump/partially blocked valve/blocked intake on pump....

try the new pump first and if that does not work, pull the lines and make sure they are clear. If they are ok then take your valve apart and check it over.

 

[CWME]

While I am waiting for the new pump I am going to strip all the lines and make sure everything is clear. I am thinking of ordering a new valve to go with the pump.

The machine is 25 years old now and has seen a lot of use. Been running this thing since I was 5 years old=) Good memories splitting wood with my Grandpa.

 

[isaaccarlson]

you said it still has power and splits wood? just making sure.

 

[CWME]

It has plenty of power. Pushing Oak through a Northern Tool slip on 4 way wedge. Not all of the Oak is clear either.

 

[isaaccarlson]

just have to try the new pump and see.

 

[CWME]

I agree, and I hope the new pump fixes the issue. I have 2 cords of Oak on the ground ready to bring home from my Father In Laws. I have at least another 3 cords of Beech still on the stump at my Sisters. I need the splitter up and running=)

 

[isaaccarlson]

If we lived closer together I'd bring mine over....but seein as I am in WI and you are in ME.....kinda far for an afternoon. LOL:jawdrop:

 

[CWME]

That would be a little more than a Sunday afternoon drive

 

[CWME]

Got the replacement pump from Northern Tool last night. My splitter is back up and running like a champ.

Northern Tool Customer Service gets an A+ in my book.