Harbor Freight 20 Ton Splitter Disassembly (slow cycle) Question

[Josh J.]

Looking for advice on disassembling the ram on a Harbor Freight 20 Ton Log Splitter : https://www.harborfreight.com/20-ton-log-splitter-61594.html

After over 2 years of use, the cycle time has become horrible (24 seconds + per swing--one way).

The pump seems to be making plenty of pressure (splits wet 24" diameter, 16" long, wet red oak) but seems to be stuck in slow speed, high pressure mode on the pump. I've torn down the control valve and cleaned it, replaced the hydraulic fluid, checked the filter, made sure the inlet hose wasn't collapsing, etc.

The only two things I have yet to do is remove and tear down the pump itself (I've removed all of the accessible plugs, cleaned the ports and checked the springs--all good), and separate the two pieces of the ram.

The ram has an allen bolt and cap on the outer end, but if you remove this, there's still a ring retaining the two parts of the ram together. Not quite sure how to remove this clip, or if that's even the way to separate the cylinder from the housing.

I'd like to get it apart to clean the wood that has accumulated in the engine end of the cylinder as I cannot get in there to remove everything, and I think (may be grasping at straws here...) that the body is packed with debris causing resistance and kicking the pump into low speed permanently.

Open to any other advice as well, short of buying another splitter.

I'm actually surprised that something from Harbor Freight has lasted this long...

Thanks!

Josh

 

[chuckwood]

Looking for advice on disassembling the ram on a Harbor Freight 20 Ton Log Splitter : https://www.harborfreight.com/20-ton-log-splitter-61594.html

After over 2 years of use, the cycle time has become horrible (24 seconds + per swing--one way).

The pump seems to be making plenty of pressure (splits wet 24" diameter, 16" long, wet red oak) but seems to be stuck in slow speed, high pressure mode on the pump. I've torn down the control valve and cleaned it, replaced the hydraulic fluid, checked the filter, made sure the inlet hose wasn't collapsing, etc.

The only two things I have yet to do is remove and tear down the pump itself (I've removed all of the accessible plugs, cleaned the ports and checked the springs--all good), and separate the two pieces of the ram.

The ram has an allen bolt and cap on the outer end, but if you remove this, there's still a ring retaining the two parts of the ram together. Not quite sure how to remove this clip, or if that's even the way to separate the cylinder from the housing.

I'd like to get it apart to clean the wood that has accumulated in the engine end of the cylinder as I cannot get in there to remove everything, and I think (may be grasping at straws here...) that the body is packed with debris causing resistance and kicking the pump into low speed permanently.

Open to any other advice as well, short of buying another splitter.

I'm actually surprised that something from Harbor Freight has lasted this long...

Thanks!

Josh

I've got the same splitter, and used it hard for a couple years, and mine is also broken down. Trouble started when it only had enough hydraulic power to split something when going in one direction, not both directions. In that one direction where there was a problem, it only had enough hydraulic pressure to retract the wedge back into the position where it could split going the other way - in other words, it changed from a two way splitter into a one way. I posted my questions on the firewood forum, and got a lot of replies and some discussion - the consensus was that there was probably a blown seal inside the cylinder, requiring cylinder disassembly and a rebuild. Sometime later this year I'll remove the cylinder and see what I can do with it. If this thing can't be fixed, I'll have to junk it. The engine has been very reliable and I'll remove and keep that. Pump is probably good too. You'll probably get more help from the guys in the firewood forum, there are some splitter specialists in there.

 

[Tape]

Personally myself doing the woodwork alone I wouldn't mind the 24 seconds cycle, it would give me time to stack it as well, I think the 24 seconds would keep me plenty busy.

 

[jpsp]

Josh, I have had the same problem after a couple years of splitting. Cycling slowed, appeared to be only running in 1st stage of 2 stage pump. Took pump off and apart. There is a shaft in the two stage pump that sheared. Ordered a replacement pump online. (couldn't find exact fit but found a 13gpm unit and was able to match fittings. Drained oil and cleaned tank. According to parts diagram there should be a screen in tank but was not present. Threw a couple cow magnets in tank for good measure. Fired up and split for maybe 15 minutes then seal started to leak. In order to get ram apart I used a pick and a needle nose pliers to work the retaining ring out of the groove. I was able to disassemble to ram and found a bad seal. Stopped by a local hydraulic cylinder repair shop and they were able to order seals- nothing in stock since Chinese manufacture. I ordered 2 sets for about $20 with shipping. Had a hell of a time getting ram back together. A buddy and I threaded heavy fishing line down the cylinder to get the shaft through the seal. Everything is internal and hard to work with.
Fired up again. Split for half hour and leaking. I think we may have tore a seal when putting back together. Have the second set of seals to try again but am thinking I will disassemble and take to where I bought the seals for reassembly.

 

[jpsp]

Update. I took ram apart once more and brought to local hydro shop. I had them machine out the seat so a beefier seal could be used. also put a taper on end of shaft for easier reassembly. Works fine now.

 

[chuckwood]

Update. I took ram apart once more and brought to local hydro shop. I had them machine out the seat so a beefier seal could be used. also put a taper on end of shaft for easier reassembly. Works fine now.

There's a shop not far from me that sells and services hydraulic stuff. I'm planning on taking my HF splitter apart and checking for any internal damage to components, it's inoperable right now. Motor runs great but the ram no longer works. If it's a seal issue inside the ram, I'm thinking about taking it apart and to a shop for rebuild/repairs. Your success is encouraging......

 

[jpsp]

Update: Added filter to HF 20 ton splitter. Valve is threaded NPT so filter block was easy to mate. Was unable to find conversion fittings to hose threaded at 22 x 1.75. Originally wanted to place filter closer to the tank. Had to reverse the return hose. At this location have built in hand warmer.
Blew out filter gasket after following directions to tighten 1/2 turn after contact. Works fine after further tightening. After market pump can be seen below. (13gpm instead of 11)- works fine with stock engine. Best advice is to keep the end of ram clean where hydraulic seals are. Hope you got yours fixed.

 

[jpsp]

 

[chuckwood]

View attachment 742157

I've got one of these, it's been sitting for a least two years now, and I'll probably have to install a new carb just to get it started. The seals in the hydraulic cylinder have gone bad, and I'm unsure right now about how to get it fixed. I've got so much firewood piled up around here that I don't need the thing running yet. I'm probably going to be bugging you for more details about the filter setup. Could you give us any more info about the aftermarket pump you installed?

 

[jpsp]

https://www.amazon.com/Tool-Tuff-Log-Splitter-Build-Kit/dp/B0748 This kit should have everything for new pump set up other than hydro conversion. Just need diameter of engine shaft. I bought the pump online then the rest of the set-up from local farm store and Northern Tool. 13 GPM pump works fine with the original engine. (original was 11)
Screwball metric threads as mentioned before so brazed a fitting to use the existing line. Easier way would probably be to get new line from pump to valve since the pump is NPT with conversion fittings to 22x1.75mm to the lines. Could not find conversion fittings anywhere- Parker didn't even have anything. I did pick up a 22 x 1.75 tap online (shipped from China) to have on hand to make my own in the future since the lines will most likely go sometime. Oh yeah I did replace the suction line also.
Hope that helps. I should have taken pictures when I took the ram apart. In a nutshell here is the process: detach hoses and ram, pullout of frame take end cap off ram, there is a metric Allen head bolt on the end. Tap the innards in to expose the locking ring (sits in a groove inside the cylinder) I got it out with a pick and a needle nose pliers. I then re-threaded the Allen bolt and pried out I would call (inner end cap)- has O-ring seal. behind that is a nut on the end of the hydraulic rod held with a locking washer- bend the tab with flat head screwdriver and remove. you can then pull the rod from opposite end of cylinder. to get the seals out I used my kids baseball bat to push through. the O-rings looked OK. Local hydraulic shop machined a larger seat to fit a "double seal"- see attached pics to compare. I ordered two sets when I had it apart. oh yeah I also had them put a but of a taper on the end of the rod to help with reassembly and they cleaned up the sharp edges on the port at the end of the rod. I used STP as lube to put it all back together- just line everything and be patient. hope that makes sense. Jeremy

 

[Josh J.]

Thank you for all of the information. I just got the splitter back out of storage to address the issue and came back across this thread.

I took the cylinder out and spent about 30 minutes pulling the wood debris out of the cylinder. It looks like the seal in there is starting to push out as well, but I wanted to make sure that the wood that was packed in there wasn't putting strain on the cylinder and having the pump go into high pressure mode.

I put it back together, fired it up, and no change.

I then pulled the pump apart, and found the same thing happened to mine that happened to your pump. The shaft came out in three chunks, so this looks to be the weak spot on these pumps.

I've heard these are 8gpm pumps from the factory, but also 11gpm as you have quoted. I love the capacity (I've split wet, 24" diameter red oak with this thing regularly), so I'm looking at the 11gpm pumps. If I can't find one to fit, I'll probably go with the kit you used. I'll let you know what I find once I get to measuring and actually buying a pump to try.

The original pump on mine is a Deli Hydraulic CBK1-C6/F2.1CD pump. I'm a little lost at this point as the specs show it as a .132 in3/r pump as seen below:



I believe this to be direct crankshaft driven (no gearing), with the Predator 6.5 hp engine's max speed of 3600rpm:



This gives me a flow rating of only 2gpm:



I'm guessing that I'm doing something wrong in my calculations--most likely missing a step.

Harbor Freight is claiming 8gpm on the splitter at this point. Maybe they downsized the pump due to issues?



I'm just trying to figure out the simplest way of getting the pump replaced with the correct specs. "Too many numbers...head hurts". ;-)

Josh

 

[triptester]

The 6.5 hp engine will handle a 13 gpm or smaller 2-stage pump.

 

[farmer steve]

@Josh J. I used these guys for a pump a few years ago for my troybuilt splitter. http://www.daltonhydraulic.com/log-splitter-parts

 

[jpsp]

Josh J. 13 GPM pump working fine on the stock engine. I have found that I need to move my filter closet to the tank. Have blown seals out of two filters when lugging. I ordered a 22x 1.75 tap from Amazon along with a 20mm drill bit. ( around $10 each) Purchased a 1/2 by 3/4 female NPT reducer at the local hardware store and drilled the 1/2 side to 22mm - essentially just drilled off the threads. Plan on threading the newly made conversion fitting to the return side of the tank with filter unit there so there will be less pressure on the filter gasket. (further away from pump) Will replace stock hose with NPT to the valve.
Jeremy

 

[jpsp]

found this page on youtube. looks like he had the same problem.

 

[Josh J.]

So, after putting this off for over a year, I'm got sick of looking at my dwindling wood stock and decided to actually work on this. It now runs.

I haven't split anything with it, but it cycles as it's supposed to. I'll try to remember to update this once I've put some splitting time on it--providing the seal on the cylinder doesn't go too quickly, which seems to be the next common issue. ;-)

First, I'd like to thank everyone for their input, especially jpsp for all of the links and sharing his experience. It made things go a lot smoother with the info provided as opposed to starting at square 1.

I did end up buying the 11 gpm pump just to keep things a little closer to stock volume. I ended up buying it from the same place jpsp did, just the 11gpm as opposed to the 13: https://www.amazon.com/gp/product/B0748NRS7Q/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1 My engine was a 3/4" shaft, but I would definitely confirm this before ordering as HF seems to change things often.

The pump comes with a 1/2" NPT outlet port as opposed to the original which had a M14x1.5 straight thread port. Harbor Freight/China loves the o-ring seal metric ports, and I had the same M22x1.75 hose/fittings that jpsp did. I decided to skin the cat a little differently on mine, and just went with a new hose and fittings.

The control valve comes from HF with a 3/4" MNPT to M22x1.75 90 degree, so with the pump being 1/2" MNPT, it was easy enough to just convert it.

I mounted the pump straight up and down with the intake port facing downward. The original suction hose went right on it with no issues:





Here are the parts that I used once the pump was mounted to adapt it to the control valve:


The hose is 1/2" 2-wire hydraulic hose, 24 1/2" long with 1 end terminated in a 1/2" JIC Female Swivel, and the other end in a 3/4" Male NPT.

The upper fitting (which went on the control valve) is a 3/4" Male NPT to 3/4" Female NPT, 90 degree fitting. Common part number for this adapter is 5502-12-12

The lower fitting (which went to the pump) is a 1/2" Male JIC to 1/2" Male NPT, 90 degree fitting. Common part number for this adapter is 2501-08-08

I could probably play around with the fitting orientation a bit for better positioning of the hose, but this is where it seemed to be the most relaxed:


I hope this adds to the information that jpsp provided and allows the next person in need to quickly/easily replace their pump.

Now, I'm off to kill the cylinder...

Josh

 

[cedarhollow]

@Josh J. I used these guys for a pump a few years ago for my troybuilt splitter. http://www.daltonhydraulic.com/log-splitter-parts

i pass by dalton hydraulics on way to knoxville, i'll have to stop in next trip to the city

 

[jpsp]

 

[jpsp]

I think I have all the bugs worked out now. Moved the filter down to the tank with 3/4" lines to and from the valve which is 3/4 NPT thread. Bought a metric tap from Amazon 22x 1.75 and made a conversion fitting from the filter to the tank. Used a water fitting from the hardware store drilled off the threads on the small side then tapped to 22mm with 3/4 on opposite. Several elbows and good to go.
Split three trailers of wood and filter has not blown its gasket. Added a four way wedge found here: https://smile.amazon.com/gp/product/B06WD4CRHG/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1 made for a different splitter- just had to grind about a 1/4 inch off each side of the wedge to make it fit. I got the filter body, lines and filter from surpluscenter.com

 

[Josh J.]

Update:

I felled a few more trees and finally got a chance to put this thing to work again. I split about two cords of semi-wet red oak.

The difference between the OEM pump (8gpm) and the new pump (11 gpm) is noticeable.

It would slow considerably when it went into the second stage of the pump. It still split the 20" inch diameter, 16" rounds, but there was definitely more load on the engine---and this wasn't nearly as wet (read: "water dripping out of the wood when split") as the 26"+ rounds that I abused it with two seasons ago.

Just my opinion, I would stick with an 8gpm or 11gpm pump if you're really going to split more than it's rated for.

That said, I love jpsp's filter setup, would love to see the four way wedge mounting mentioned above, and thank him 1000x for the information he gave me that allowed me to reconfigure mine to working order again.