Help! PowerTrac 1418 hydraulic hose burst!

[davesisk]

Ok, so I was digging out the area where the patio was going to go to level it. I was totally amazed that, even with it's light weight about around 1000 lbs, this PT1418 (approximately equivalent to a current 422, AFAIK) was able to dig out this really tough soil with rocks and roots. This by just angling the bucket down and driving into the soil, then tilting the bucket up as I went. I essentially lifted the front end of the machine, then curled the bucket up as I drove the tractor forward (sound like proper technique?) I'm thoroughly impressed with this little machine's capabilities! I also pulled a trailer loaded with 2.3 tons of crush-n-run and unloaded and spread this material. And during the easy work of unloading the crush-n-run is when "it" happened.

The hydraulic hose connecting the hydraulic pump and the oil cooler burst, and starting spewing oil. I'd assume the fluid flows from the little radiator to the hydraulic pump (or do I have it backwards?). The person working with me noticed it and I shut it off. We then restarted it to see the source, and sure enough it looks to be only the hose. Whew!

Anyway, questions now:

1) I'm sure I can order this hose from the factory. I've been told that, if I take the hose with it's fittings to a Carquest, they can re-use the fittings and make a new hose, probably even a reinforced hose stronger than the OEM part. Has anyone done this? I'd like to get it back in commission tommorrow if possible, and Carquest sounds faster than the factory.

2) I'm sure I have to bleed the hydraulic system of air after installing the new hose. How do I do this?

3) I haven't yet noticed the fan for the hydraulic cooler (the little radiator) switching on. There's apparently a temperature switch, which I'm guessing may be shot. I'm sure I'd really need to order this part from the factory, of course. Will I do any damage by continuing to use the tractor if the switch isn't turning the fan on? How can I tell, is the fan loud? Is it possible what might have caused the hydraulic hose to burst, or is that more just a function of hose age?

4) Was I running the tractor too hard by my digging technique? Or is a burst hose a reasonably common thing?

Any help appreciated!

Regards,
Dave

 

[Charlie_Iliff]

Dave:
One of the reasons I like the Power Trac is that things like the hydraulic hoses are easily procured locally. We have a number of places around here (Maryland). You only need to make sure the hose is rated for the pressure (3000 working psi on mine)
The fan probably should have been running. Was the oil really hot when the hose broke? Mine gets pretty hot when running a mower or tilling.
There is a relief valve that should keep the hose from being over-pressurized, no matter how you use the machine. Unless you bend or break something mechanical, which is hard to do on a Power Trac, it seems to me as if the best technique is the one that works best. Yours sounds pretty good.
My 1845 is new, and I haven't broken any hoses. I have broken a few on other tractors, however, after years of use, UV exposure, flex & chafe. Usually I've gotten small leaks. You'll want to take a pretty close look at the other hoses.
Power Trac did warn me about properly bleeding the pump when I change the filter. They said that 40 seconds of running with an air lock could trash an expensive pump. You need to call them and get them to talk it through with you. (My new book is no help. They are used to helping owners on the phone)

 

[MChalkley]

Dave - <font color=blue>The hydraulic hose connecting the hydraulic pump and the oil cooler burst, and starting spewing oil. I'd assume the fluid flows from the little radiator to the hydraulic pump (or do I have it backwards?).</font color=blue> I'm not sure, but I suspect the cooler is between the pump and the tank. The line that burst, if it goes to or from the oil cooler, is not a high pressure line.

<font color=blue>I've been told that, if I take the hose with it's fittings to a Carquest, they can re-use the fittings and make a new hose</font color=blue> They can't re-use the fittings, but they'll need them to make sure they put the right ones on the one they make up for you. Many auto parts stores, and other places too, can make hoses.

<font color=blue>I'm sure I have to bleed the hydraulic system of air after installing the new hose. How do I do this?</font color=blue> You won't have to bleed it after replacing this hose.

<font color=blue>I haven't yet noticed the fan for the hydraulic cooler (the little radiator) switching on. There's apparently a temperature switch, which I'm guessing may be shot.</font color=blue> The sensor may be shot, but I'd make sure the cooler is getting close to 180 degrees or so before I assumed that. You might find an infra-red thermometer a good investment, if the $150 or so doesn't scare you off. Every since I got one, I've found them indispensable, especially when you've got something to compare to (either a known "good" or "bad" value, or another of the same thing, such as wheel bearings). As for whether it's coming on or not, you could short the temp switch to force it on - it the fan works, you know it's ok. Then you could put a temporary test light on the fan terminals - if it comes on when you're using the tractor, the fan is on.

<font color=blue>Was I running the tractor too hard by my digging technique? Or is a burst hose a reasonably common thing?</font color=blue> It's not likely that your "digging technique" is going to burst a hose. And it's not possible for it to burst the one that's leaking. In fact, since that hose most likely isn't a high pressure hose, it's probably not a pressure-related failure at all. Does the hose flex at all? Does it rub against anything? Can you see any physical damage to the hose? (Also, check the writing on the hose - there should be a psi rating on it somewhere. What is it?)

Hope this helps.

 

[MossRoad]

I think the best advice was to call Power Trac on the phone and ask them what to do as far as bleeding the system. From what I have heard, if it is even required on this hose, bleeding is not that hard if you use the hose that Power Trac provides. Also, one note on hydraulics: Make sure you keep it as clean as possible when you change the hoses. No dirt.

 

[PTRich]

A quick call to Power Trac is in order. Bleeding the pump is very easy if they think it is necessary. You will have to do this when you change your hydralic filter anyway so you may as well learn how. Did you change your filter when you purchased your machine? If you want to order a hose from Power Trac you may want to order a filter also.
PTRich

 

[davesisk]

Yup, it looks like the hose rubs against the oil cooler. Thanks for all the advice you folks! Much appreciated. I will call the factory this morning, as I need to get the manuals for this thing anyway.

If anyone is interested, I'll post the bleeding procedure here after I learn what it is.

Best regards,
Dave Sisk

 

[MChalkley]

Dave - As Charlie, MossRoad, and Rich have suggested, it's definitely a good idea to check with the factory re the need to bleed the system. However, the only time this is necessary is when you open the input side of the piston (hydrostatic "transmission") pump. The filter is always on this side of the pump, but the oil cooler is never on the input side - it's always on the output side. The reason you have to bleed the system when opening the input side of the piston pump is that that're very sensitive to cavitation, not to mention being run dry, which can happen if there's air in the input side. The gear (implement) pump isn't so sensitive, so can bleed itself without damage, as long as you let it run a minute or so after starting it. Still, it's never a bad idea to check with the experts...

 

[MossRoad]

A little hydraulic theory never hurts either. Thanks, Mark /w3tcompact/icons/smile.gif

 

[PTRich]

Everyone take note, we know who is educated in hydralics (I am not). We will probably be asking you questions in the future, I hope you do not mind. You seem to have a good understanding on how they work.
PTRich

 

[davesisk]

Update on PowerTrac 1418 hydraulic hose burst!

Thanks for all the suggestions, folks. I've talked to Don at the factory twice today, which were both good conversations (nice guy!).

Anyway, I got the busted hose off this morning. It's rubbed against a steel plate where the front hydraulic pump and engine meet. Essentially, a crack was abraded into it. So, I spent about an hour getting the hose off, and went to Carquest to get one made. They made it, I can back, put it on, and oil was still spraying. It appeared to be coming from where the crimp was on the fittings. So, I took it back off and went back to Carquest. I watched the fellow make a new hose (the first guy had used the wrong size crimp arbor on the little hydraulic press they use for crimping). He made a new hose, I can back home, and put it on. Oil was still spraying! I started checking other hoses, and found another with a similar worn spot. This one goes from the bottom of the front pump underneath the engine, then curls back up to some sort of splitter type valve mounted to the left side of the engine bay. I'm going to take this one off tomorrow morning, and go back to Carquest. It's possible that the first hose wasn't spewing yet, but might have burst very soon.

This second hose looks like it's going to be a real pain to get off. There doesn't appear to be enough room to unscrew the fitting with a crescent wrench. Any suggestions?

Also, according to Don at Power-trac, nothing on the pressurized side of the pump needs to be bled after changing a hose (only the suction side, tank-filter-pump).

Do hoses fail this often, or am I just having to play "catch-up" on maintenance that hasn't been done to this machine?