REPLACING PTO PUMP

[J_J]

I have to replace the PTO pump in my PT-1445. I suspected it was going bad after trying to use the stump grinder/trencher, and several other umplements. They would run, but woule slow down to dead stop. I don't have much room to unbolt the pump and slide it off the back of the tram pump so I thought I would take the radiator off the back. Found out that it will not come off unless the engine is raised about 6 to 8 in. I gave up on that idea. and decided to just unbolt the engine, and raise the engine package up about 6 in. I only had to remove one radiator hose to get at one of the engine hold down bolts. I then raised the engine up enough to slide a hydraulic wedge under the engine mount and raised the whole engine assembly a little at a time and put blocks under the engine frame.. The PTO pump was removed and taken to my local hydraulic shop to verify my assumption that it was bad, and it was. They took it apart and showed me the inside of the pump which had wear marks.
I will try and take some pictures of the wear points. I ordered a new pump, and should be in a couple of weeks. I asked about rebuilding it, and they said that it wasn't worth rebuilding and the parts would be more than the cost of a new pump. It is a Eaton/Cessna 16 gpm pump with a splined shaft. What ticks me off about the setup, is that there is no reason for the PTO pump to run unless you are using the PTO. Belt driven PTO, with electric clutch would have been better. In all of the PT's , the PTO pump is always running when the engine is running. Should be easy enough to reinstall everything .

 

[SnowRidge]

<font color="blue"> In all of the PT's , the PTO pump is always running when the engine is running. </font>

In my PT-425 it has to, it is also the steering pump.

 

[ClintBlake]

How much is the new pump? How many hours does the old pump have on it?

 

[Spiffy]

Bad pump; that stinks /forums/images/graemlins/frown.gif

My 2445 is setup a little different, but sandwiched between the variable pump and the steering/loader pump, it also must run all the time.

I'm curious to see your pictures because I didn't think they were supposed to wear much unless under constant load. My bigger issue is that I'd really like a reversing circuit, but of course that takes much more valving.

I had weak aux this fall too, but got lucky and only had a jammed relief valve. Hopefully, it cooperates this spring.

 

[MossRoad]

I think mine has a two section PTO pump. One section is for the main 8GPM PTO that runs implements and the other section is for the steering rams and lift rams, as well as the auxillary PTO which operates with the knee lever. Since they are bolted together, they always run, even though we don't need the main PTO section running unless there is a powered implement attached. However, clutches and brackets and pulleys and belts all add up to increase the cost of the unit. As with everything, there are trade offs. /forums/images/graemlins/crazy.gif

 

[SnowRidge]

Moss, check your plumbing. /forums/images/graemlins/blush.gif Er, I mean hydraulic lines. I think you will find the steering and PTO use the same pump section, while the lift and tilt mechanisms use the other.

 

[MossRoad]

Will, do. Thanks. /forums/images/graemlins/smile.gif

 

[stray]

JJ I am looking forward to the pics and info. Sorry about the failure. How many hrs on the PTO pump and when your ready what do you think made it fail?

Here is a pic of my set up.
I believe this statement and photo to be true.
All cylinders work off the same pump. This would explain why the lift stops lifting when you start steering and when using the mini hoe you loose break out power when activating the steering. With some experience you learn to work with this (the nature of the beast).

 

[toy]

Hey JJ sorry to hear about your pto pump. Hope you can get it fixed without too much expense. Was it a brute to get the engine up or did it come up pretty easy? If I understood right you didn't have to take but one hose off ,plus naturally the ones to the pump. Let us know how easy the engine goes back down and the mounting holes line up and how much trouble you have installing the pump. Again hope it don't cost too much and you get it running again soon.

 

[J_J]

I have three pumps. A single pump for the lift and steering. A large tram pumps on the other end of 4 cylinder gas engine. The third pump is the PTO pump, piggy backed on the tram pump. Unfortunately, the PTO pump runs when the engine.

 

[J_J]

The new pump is about $350.00, but I didn't get it from PT. Nobody knows the age of 1445 . Can't remember the hours off hand but something over 1250.

 

[J_J]

The wear is from particles in the oil. The way it was explained to me is that the filter, filters everything larger than 10 microns. The smaller particles are free to flow in the system, and get in the smaller places, rotors, slide plates, etc. My filter is on the suction side of the tram pump, and therefore, the other pumps get the fluid directly from the tank As you bounce around on the PT, some of the finer particles are stirred up and contributes to more wear. I believe each pump should have it's own filtering. I will go ahead and change the oil and filter when I install the new pump. I am still not sold on the synthetics, although they seem to have some promise. The cost is double or tripled in some cases, but do they give double or triple the service?

I still have a Kohler engine on a Dixie Chopper that has 10 micron hyd filters for the hydraulics, and also a 1 micron by pass filter. It is hooks up in parallel. The engine was looked at after about 5 years, and they said it was as clean as a new engine. So I am thinking a filter like that would be a good idea.

 

[J_J]

Your reversing circuit is easy to do. If you are talking about the PTO, then just reverse the hoses to the PTO. A double acting solenoid valve with a toggle switch would work. Switch up, hyd motor runs one directions, switch down, the motor reverses directions.

 

[J_J]

The engine assemble raised up fairly easy after realizing the radiator was attached to the engine mount. Could not tilt the engine very much without damage to the radiator. I raised it a little at a time using my hydraulic wedge that opens up like jaws of life. Installing the pump should take about 20 min. I will prime up the pump before installing the hoses, although the hyd technician said being it was that close, it would prime it self.

 

[SnowRidge]

<font color="blue"> I still have a Kohler engine on a Dixie Chopper that has 10 micron hyd filters for the hydraulics, and also a 1 micron by pass filter. It is hooks up in parallel. The engine was looked at after about 5 years, and they said it was as clean as a new engine. So I am thinking a filter like that would be a good idea. </font>

That's an interesting concept. Some of the oil would flow through the one micron filter and would catch anything smaller than 10 microns and one micron or bigger. Eventually, most if not all of the oil would flow through it, and virtually everything one micron or bigger would be trapped. It wouldn't be a panacea, but it should help.

I too don't care for the fact that the only filter is in the tram circuit. Crud can circulate amongst the other circuits for a long time before it just happens to get sucked into the filter. Every time a PTO line is connected or disconnected there is the risk of introducing some contaminants to the system. I've wondered about installing a filter in the PTO return side, but I'm not sure if it is safe to do so. I've read at least one article that says filtered returns are a no-no.

 

[marrt]

This question of adding additional filtration to the hydraulic circuit has interested me for some time. Power Trac uses a cheap but common filtration approach of filtering the oil before the tram pump. Unfortunately, there are two huge downsides to this approach. First, the other pumps get unfiltered oil directly from the reservoir. And as JJ mentioned, these pumps run continuously. Although they are usually gear pumps and are a bit more tolerant of contamination, they suffer anytime the oil is contaminated. Since contamination can easily enter the circuit from the PTO connectors, the surface of the hydraulic cylinders and the reservoir cap, this is a problem. Second, there is a serious risk of tram pump cavitation, or of the filter going into bypass, if the filter gets clogged.

It would be interesting to add a dedicated flirtation circuit, probably in parallel off a return line, to continuously filter the reservoir oil using an electric pump. With a one micro filter, this setup should ensure that the reservoir oil maintains a much lower average level of contamination. I wouldn’t be surprised if such an approach wouldn’t double the pump life.

 

[SnowRidge]

Kidney filtration, I believe it's called. That is essentially what we have now, with the tram's charge pump kidney filtering for the other circuits and input filtering for itself, although not at the one micron level. Adding a one micron kidney filter would be an improvement, but I would rather find a way to eliminate the crud before there was any chance of it getting to a pump or cylinder. The only way I see of doing that is a return filter on the PTO circuit or input filters on all the pumps. Wish I knew more about hydraulics, as methinks one could do considerable damage it everything wasn't done exactly right.

 

[MossRoad]

Aren't all three pumps sucking oil at all times, no matter what we are doing? I thought they constantly sucked it in and just sent it back to the reservoir if it is wasn't being used to accomplish any work. So even while we are just sitting there letting the unit idle, fluid is getting sucked through the filter by the tram pump. I think they chose the tram pump for the filter circuit because it is the most expensive pump to replace and the most susceptable to dirt? If we put a filter on the inlet side of the PTO circuits, all points would be covered, wouldn't they. Is 10 microns enough or do we need to go smaller? Will a 1 micron filter be able to flow the GPM we need? If we had two filters in parallel, one being 10 microns and one being 1 micron, would the smaller filter get any flow, as doesn't fluid take the path of least resistance?

Like you said, I too, wish I knew more about hydraulics. /forums/images/graemlins/crazy.gif /forums/images/graemlins/tongue.gif

Any of you signed up for that hydraulics newsletter?

 

[Spiffy]

I'm no expert here: but if there is a 1 micron version available I'm thinking of a simple alternative:

When changing your filter, put a 1 micron in instead, run a few light duty tasks totaling an hour or so, then go back to a 10 micron. In all reality even 10 micron is pretty fine [1/10th the thickness of a sheet of paper; 1 would be 1/10 that: 39 million'ths of an inch] , but fine abrasives can add slow wear, so I can see the concern.

Now if somebody would be kind enough to put a pressure/vacuum gage in line when they try it and report back we could all [at least everyone with similar circuits] know how safe it is! /forums/images/graemlins/grin.gif

 

[Spiffy]

You're right JJ; I don't think it would be too hard. However, I am imagining 2 solenoids and a couple extra hoses & T's that would need to be stuffed in there, but I don't think my 2445 is as short on room as the 425 guys have to work with.

Of course, that's still only number 2 on my list anyway...now if I'd spended as much time trying things as babling about them, I'd actaully be able to give some intelligent information! /forums/images/graemlins/blush.gif /forums/images/graemlins/grin.gif