Help with a leaky splitter hydraulic valve

[rmacvt]

I’m new to the site and looking for help on my venerable splitter. It has provided trouble-free service for close to 40 years, so I do not begrudge it needing maintenance.

The problem is a leaky hydraulic valve. The main problem was easily solved: A steel pipe was shearing off. After breaking it free with a little twist, plus some quality time with a screw extractor and other tools, I was able to replace that pipe, button it all up, change the filter and fluid, and fire it up. It now leaks only slightly, but enough that I want to address it.

Question 1: What model is the valve? It is a Prince valve, for sure, and it looks very close to an RD5200 (but remember it's 40 years old -- was the RD5200 around that long ago?). From what I can see, it’s a two-spool monoblock. There is a data plate on it with a serial number, but the model number is blank. Prince says the model should be stamped on the body, maybe on the “end cap opposite the handle.” If that means the end cap on one of the detent assemblies, it isn’t there or anywhere else I’ve been able to find.

Question 2: Hydraulic fluid appears to be weeping from the junction between the detent body and the valve body. I'm fairly sure that's the source: After careful cleaning, I don't feel any fluid on either side of the drip. (Please excuse and correct any faulty terminology. I’m no expert.) What kind of seal is on that junction? I’ve tried tightening the cap screws that secure the assembly to the body, and that didn’t help. I’m looking at Prince’s RD5000-series parts manual and don’t see a seal there.

Question 3: One of the valves stopped autocycling, suggesting to me that one of the relief valves needs adjusting. Is it possible that a severely misadjusted valve could cause enough pressure to force a leak?

Question 4: How long does the valve stay pressurized after the engine is shut down? Does it drain down immediately?

Question 5: If it were you, would you proactively replace all these 40-year-old hydraulic lines?

The third picture shows the two end caps. It's the nearer one that's leaking. Note the rough-looking gasket: Neither my splitter partner nor I know how that got there, but that doesn't seem to be the source of the leak anyway. The fourth picture shows the leak in action.

Any help is appreciated. I've been using this splitter for decades, but I've only been working on it for a few days...

—Rick

 

[farmer steve]

Welcome to AS @rmacvt. No a big valve guy but check at surplus center for something that might be compatible with your splitter. Someone with more knowledge than me will be along shortly. Good luck.

 

[Chevboy0167]

http://www.princehyd.com/Resources/Parts-Manuals

 

[meteoritedude]

Your valve resembles the autocycle valve that chevy's link goes to. Typically there's a spool seal and and o-ring at each end of the spool aka shaft. They are easy to replace. Parts list shows them. Those caps on the bottom where the old looking gasket is, are designed to keep the elements out. They protect the return springs and spool against corrosion. Part of the spool sticks out in there and operating lever pulls the spool in or pushes out. So if it gets dirty or corroded, it may bind and wear the seals. Most valves don't have drift (bleed down) in neutral. 40 yr old lines may be due to be replaced. They are cheap at SC, go for it. If you replace the seals, do both. If ram moves slower than it used to, and you get drift (bleed down), you probably have a bad piston seal. Hydraulic oil also will also accumulate water and look like mayo (emulsion) over time. Cheap to replace.

Parts are cheap here:
https://www.surpluscenter.com/
get seals from OEM.

Further examination of the valve schematic - which I have personally never worked with - I am more familiar with tractor and other heavy iron valves - it appears the auto function involves a piston in the bottom of the valve controlled by a pressure valve (not to be confused with the overpressure valve), When pressure builds up past a set value, it kicks the spool out to neutral. That area is critical to be clean and free of debris and corrosion for freedom of movement. That will prevent the valve from autocycling. Valves in my world have a float function which can be disabled when that area gets gummed up. Sometimes those covers have a hole that allows you to see oil leaking out when the seal fails, but is also an entry point for stuph you don't want. It also allows for it to not be airbound. I have seen valves with the longer covers for float control unvented.

 

[Gabby3545]

I’m new to the site and looking for help on my venerable splitter. It has provided trouble-free service for close to 40 years, so I do not begrudge it needing maintenance.

The problem is a leaky hydraulic valve. The main problem was easily solved: A steel pipe was shearing off. After breaking it free with a little twist, plus some quality time with a screw extractor and other tools, I was able to replace that pipe, button it all up, change the filter and fluid, and fire it up. It now leaks only slightly, but enough that I want to address it.

Question 1: What model is the valve? It is a Prince valve, for sure, and it looks very close to an RD5200 (but remember it's 40 years old -- was the RD5200 around that long ago?). From what I can see, it’s a two-spool monoblock. There is a data plate on it with a serial number, but the model number is blank. Prince says the model should be stamped on the body, maybe on the “end cap opposite the handle.” If that means the end cap on one of the detent assemblies, it isn’t there or anywhere else I’ve been able to find.

Question 2: Hydraulic fluid appears to be weeping from the junction between the detent body and the valve body. I'm fairly sure that's the source: After careful cleaning, I don't feel any fluid on either side of the drip. (Please excuse and correct any faulty terminology. I’m no expert.) What kind of seal is on that junction? I’ve tried tightening the cap screws that secure the assembly to the body, and that didn’t help. I’m looking at Prince’s RD5000-series parts manual and don’t see a seal there.

Question 3: One of the valves stopped autocycling, suggesting to me that one of the relief valves needs adjusting. Is it possible that a severely misadjusted valve could cause enough pressure to force a leak?

Question 4: How long does the valve stay pressurized after the engine is shut down? Does it drain down immediately?

Question 5: If it were you, would you proactively replace all these 40-year-old hydraulic lines?

The third picture shows the two end caps. It's the nearer one that's leaking. Note the rough-looking gasket: Neither my splitter partner nor I know how that got there, but that doesn't seem to be the source of the leak anyway. The fourth picture shows the leak in action.

Any help is appreciated. I've been using this splitter for decades, but I've only been working on it for a few days...

—Rick

A guy who delivered me 10 cords suggested Blue Devil Hydraulic Stop Leak. Said he used it in his big delivery truck with a grapple for unloading. I tried it last year and the splitter hasn't leaked a drop since! Not cheap, but it works!

 

[rmacvt]

Thank you all. This info has helped me figure out next steps. MeteoriteDude, thanks for the explanation of the endcaps -- very helpful.

As I mentioned above, I can't find the valve's model number. It looks a lot like the current RD5200, but I don't know if that was being manufactured in the 1980's. I've been using the RD5200 parts manual, but I don't know if the internals are the same as mine. That makes me nervous about ordering a seal kit that may turn out to not be compatible.

Blue Devil -- sounds interesting. I'll explore that idea.

As regards hoses, more research makes me think I should just replace them. None of us splitter owners remember ever replacing them. They are old enough that one of the laylines does not conform to modern Parker convention. How old that makes it, I don't know. I do know the fittings are all rusty, some very. Replacing them just seems wise if I'm going to this much other work.

So, work continues. I'll update this thread as I learn and decide more. Thanks again.

 

[Big_Eddy]

Looks like a Prince Autocycle for sure. The basic design has not changed in decades. Pretty good chance the 5200 parts will interchange. The leak is most likely a failed O-Ring on the spool.
I stay away from all additives, especially leak sealers. They will plug leaks, but the plug up other things too. Better to fix the problem anyway.
I replace hoses when they leak or fail, but not sure I’d recommend that approach. I have had a couple of hydro fluid baths over the years.

 

[rmacvt]

Big_Eddy, you're helping me decide that new hoses are the way to go. I think I've outgrown living on the edge...

For someone's future reference, I'll mention that the splitter itself is from a Vermont company called East Hill. They were around back in the 80's, maybe a little either side, and then they sold out to somebody. As things developed, I understand that the East Hill guys later got back into the business and started Built-Rite, which continues to this day. I love the splitter, and both East Hill and Built-Rite splitters seem to be well regarded.

 

[Am leaf]

Thank you all. This info has helped me figure out next steps. MeteoriteDude, thanks for the explanation of the endcaps -- very helpful.

As I mentioned above, I can't find the valve's model number. It looks a lot like the current RD5200, but I don't know if that was being manufactured in the 1980's. I've been using the RD5200 parts manual, but I don't know if the internals are the same as mine. That makes me nervous about ordering a seal kit that may turn out to not be compatible.

Blue Devil -- sounds interesting. I'll explore that idea.

As regards hoses, more research makes me think I should just replace them. None of us splitter owners remember ever replacing them. They are old enough that one of the laylines does not conform to modern Parker convention. How old that makes it, I don't know. I do know the fittings are all rusty, some very. Replacing them just seems wise if I'm going to this much other work.

So, work continues. I'll update this thread as I learn and decide more. Thanks again.

If it's 40 years old what does it owe you? Just replace the valve. Tear it down and see if it's worth having as a backup maybe. But I would highly recommend not messing with hydraulics if you'd seriously consider using stop leak...

 

[rmacvt]

Thanks for the suggestion. I found a local hydraulic specialist who is going to replace the seals and fabricate new hoses all around. If the splitter saw heavy commercial use over a period of decades, I'd have considered replacing it. However, it sees seasonal use and has never been pushed all that hard, so I don't think there's a lot of internal wear. Replacing the seals is around half the cost of a new valve.
BTW, once I removed the valve from the splitter, I found a casting number on the bottom that confirms it's a Prince RD5200. Still haven't found a specific model number.

 

[panther5x]

rmacvt, I dug back in my emails and found my inquiry to Prince. Indeed the one I have on mine is an RD5200. Snippets from them below.

Rick


Hello Prince,

I've looked through every place I can find on the Internet to try and help me identify the model of valve I have on my woodsplitter without success. I'm hoping you can assist or redirect me to someone that might be able to.

It's a dual lever, auto cycle valve with the stamping "HCI-PRINCE" on it. There is a metal tag on the left side of the valve (looking at the handles) that says "Prince MFG Corp" and SN 000169934". There is nothing in the Model number field. I'm looking for a spec sheet so I know what I have.

Pictures attached. Can you help me?



They replied with this:

Hello Rick
I think the SN is 000169984
Based off that you would have our auto cycle valve. RD523MMEE5A1A1
Here is a link. It us with the RD5200 Valve. Prince Manufacturing Corporation > Products > Hydraulic Valves > Mono Block (princehyd.com)

 

[rmacvt]

Well, whaddya know? That's really interesting and helpful -- thank you, panther. I looked (but not very hard) for a Prince contact email and decided not to bother them. Yours looks like the spitting image (or should I say splitting image) of mine, right down to the data plate missing the model number.
Thanks so much for sending that along. I'm still waiting for the shop to get done with mine and will report on the outcome.

--Rick

 

[rmacvt]

Splitter
Hello all, After these several months, it’s time for an update and maybe the end of this tale.

To summarize, I replaced all the hydraulic lines and, of course, the cracked iron pipe. I replaced the filter and fluids, then tried running it. It worked, but it continued to weep hydraulic fluid from the valve so, as noted above, I brought the valve to a local hydraulic shop.

When I got it back, it didn’t work at all. Come to find out, the guy that overhauled it didn’t have a manual and just guessed at what was needed. A key piece of info came from Panther5x who had learned that the valve is a Prince RD523MMEE5A1A1 . Web-searching that number yielded a great document on the Surplus Center website (link here) that describes in detail how the valve works. To their credit, the guys in the shop were great: I brought the valve back to them along with the SurplusCenter doc and the relevant Prince manual. A couple of weeks later, all was well, with no extra charge.

Once I put it all back together, everything was leak-free. I just needed to adjust the valve detents. I’m back in business.

It would have been a lot faster to order a new valve, but this specific model seems to be around $500, and I spent much less getting it overhauled. I feel better reusing what’s there.

In the shop's defense, it turns out they work mostly on heavy machinery and not usually on anything this small. It all ended well.

An interesting footnote (interesting to me, at least) has to do with Prince Manufacturing. I decided to try what Panther did, which was to ask Prince exactly what I had. I’m real glad Panther asked, because when I tried, Prince found no record at all of my serial number. It perplexed Prince as much as it perplexes me.

Now, it’s on to my MS270 saw that won’t start — again — but that will be a different thread. Thanks, all, for the help. This really is a great site.

Rick