Skat Trak 1700C Skid Steer

[rpaoness]

Figured I'd post. I was fascinated by how much some routine maintenance items made the machine work so much better.

Zeb is planning on cutting the hydraulic filter apart to see what's in it.

"Repairs" so far:
- Engine oil / engine oil filter (looked like tar coming out. I believe the last oil change was when I had the machine at my house last about 4-5 years ago).
- Wiring harness re-do. A previous "mechanic" had dropped the lift-able cab on two chunks of the machine wiring harness. A combination of these crappy blue-butt crimp connectors corroding and the marginal fuse holders resulted in all kinds of electrical gremlins. The worst of which was that the boom lift/safety bar interlock didn't work. There was a jury-rigged clamp that you had to clip on the battery positive at your feet to get the boom to unlock.
- About 2+ hours with the pressure washer trying to empty the belly pan out enough to make out hoses, wires, etc. in the 6"+ deep muck that had collected.
- The left wheel drive motor was "lazy" (much slower than the right, made turning almost impossible in one direction). Turns out under the muck there were three hydraulic pumps in series, left drive motor pump, right drive motor pump, and boom/bucket/acc hydraulic pump. Each motor pump has a shaft with a square drive on top that I assume varies the angle on piston-type swashplate pumps (like a car AC compressor I assume). The top of the square was worn so that the left lever linkage had a ton of slop - resulting in no rotation of the shaft. Removed the attached lever and did some weld-build up on the square. Some additional grinding and it was back together. Hopefully it holds up.
- Added hydraulic fluid. Figured one 5-gallon bucket would sufficiently top it off since there were no low fluid symptoms. Empty the entire bucket - still didn't show up on the sight glass. Then I bought another bucket. Emptied it into the machine. Still nothing on the sight glass. Guess I need to buy more oil.
- Replaced the hydraulic filter. This was the most fascinating "fix". Prior to replacement, even at idle, no combination of hydraulic controls would result in any appreciable engine RPM/load change. After the filter change, using either drive motor or even stalling the lift/curl bucket controls would make a noticeable engine load change. The travel speed (based on the highly accurate butt-dyno) seems to be up 20-30% for a given RPM...

[kevm14]

That is some serious neglect but I think that is pretty normal for machines like that.

[rpaoness]

I seem to never document filter numbers, and odd applications like the skid steer are hard to match up:
- The engine oil filter is a Baldwin BT237 / Carquest 85459 / WIX 51459
- The hydraulic filter is a WIX 57052
- The fuel filter is a WIX 33166 / Perkins 26560017
- The air filters are Donaldson P182062 / WIX 42518 (primary) and WIX 42519("safety")

[rpaoness]

Changed all of the filters on Friday before bringing it back up to VT to clear a path for the well drilling truck.

Had a little trouble with the stupid square o-ring design on the fuel filter but went on OK-ish I thought. Lift pump seemed to only do like 1/8 or so stroke and seemed like it wasn't pumping well. Managed to get the new filter full and then had to crack a couple of injectors to get it to start.

Got up to Vermont, started OK and got off the trailer. Ran about 5 minutes and then a passing neighbor stopped to talk to me so I kinda had to shut it off. Would not restart. Purged air out of a couple injectors and got it to run, but only 3 or 4 minutes. I was now stuck blocking about 1/2 the road and could not get it to restart even with air purges.

Decided to pull off the lift pump and troubleshoot. Lift pump had some stuff on the built in filter screen, but didn't look too bad. Pumped fine on the "bench". Reinstalled and it went back to 1/8 or so stroke only. Pulled off the fuel filter (I had a spot on the o-ring that I had crossed, potentially a super-minor air leak?) and couldn't get any fuel from the lift pump to the filter housing. I then removed the line from the pump to the filter. The line was completely blocked with some super-hard rust-like crud for the first 3" or so of the line. I took a drill and hogged out what I could easily reach and then tried to break up the deeper-in crud in the 90 deg elbow. Finally got it to push through. I flushed it with some gasoline and blowing through it 4 or 5 times and then reinstalled.

I was then able to get decent pumps out of the lift pump, hand-primed the system for a few minutes since I was now worried about a weak battery and didn't want to make matters worse. Started relatively easily and ran fine after that.

I think there's roughly 3600 hours on it - I need to remember to check the hour meter next time I'm up there.