Power Steering Pump Repair Kama 554

[3RRL]

You may have seen some of the work I've been doing with the Kama 554 these last couple weeks around the homesite and especially the road work in my Log Home Thread. Well, my power steering had been acting funny for some time now. Sometimes working just fine and other times it gets really hard to turn the steering wheel. I did the usual inspection, checked for leaks, checked the fluids and filter, checked the cylinder and all the banjo fittings etc. to see if any of that affect it. But I saw nothing to indicate any problems.

I kept working the tractor even though it was hard to steer when suddenly I lost ALL steering. I had just checked and added fluid too. The steering wheel just spun around not moving the wheels. I had to get it to camp and used the steering brakes to navigate the winding dirt road.

When I got back to camp I opened the hood and noticed the lower left side of radiator and surrounding area was covered with hydraulic fluid. I checked the steering reservoir and it was empty, so I figured it sprang a leak somewhere. I filled the reservoir a little, started the Kama up and worked the steering wheel to see where the leak was. There was a small stream shooting out towards the radiator from the bottom of the power steering pump.

 

[3RRL]

The stream was coming from the bottom and I could tell it was coming from that round black socket head cap screw that is bolted directly below the high pressure out line, on the bottom of the pump. Of course I could not tell it was a socket head cap screw yet. I had to get a mirror to see since the pump sits on a slight angle inwards. Not only that, but the loader frame up there was in the way too, so I couldn't get an Allen wrench in there as it was.

I decided to take the pump off so I could get to that black screw. Well, that's not as easy as it sounds. I found there was very little room between the radiator fan shroud, the alternator belt (which Larry and I just changed) and the engine block. To get in there and swing a wrench to loosen the pump bolts, I had a choice of removing the radiator or trying it by removing the alternator. I chose the latter.
You can see Loretta holding the alternator. See the belt, fan shroud and where the pump body is. There are 4 bolts to remove and the 2 inside ones are a pain to get to to swing a wrench in there.

 

[3RRL]

I had already removed the suction line and also the high pressure line, so I considered myself lucky when I got all the bolts out and loosened the pump. I slid it forward to get it out of there and guess what ... the pump hit the radiator fan shroud and the pump shaft was still in the drive mount. Crap!
I decided to rotate the pump instead so I could get to the bottom and that worked out.

Here is a photo of the socket head cap screw I had to remove. The leak came from between the cap screw and the pump body. I was hoping it was not a crack.

 

[3RRL]

I removed the cap screw to find the rubber coated washer, known as Dowty seals or Stat-o seals had a tear on the side where the leak was.
Here are a couple close ups showing the bad seal on the bottom of the first photo and then on the top left in the second photo.



I cleaned of the pump body and inspected it to be sure there were no cracks in it and it was fine. So the leak must have come from that tiny tear in the seal. But I was at camp and about 1500 miles away from Chip to get replacements for that Metric seal.

Not only that, I looked inside the body and saw a threaded plug with a small restriction hole in the center, but it was just rolling around in the hole, not threaded into it's place! That must have been the restriction I felt every once in a while when it was floating around plugging up the flow. I also found a couple slivers of steel that looked like chips inside. They also could have caused the problem.
Anyway, I screwed it back where it belonged inside that hole.
Here's a couple shots of that restrictor plug.



My next problem was how to fix that rubber covered washer so I could get back to work.

 

[3RRL]

Now I was ready to reassemble the cap screw if I could get a rubber coated washer.
Not having a replacement, I took a razor blade and cut all of the rubber off the washer and cleaned it up good. Then I got my Harbor Freight Metric "O" ring kit out. I found a skinny "O"ring that fit inside the washer and was about .020" thicker than the washer. It also fit nicely around the threads of the plug.

My thoughts were if I could get that "O" ring to stay inside the washer when I put it over the plug, it would seal perfectly. The "O" ring would squish down to seal and the washer would keep the "O" ring from getting blown out. The washer acted like a counter bore for a ORB fitting and the repair worked perfectly. How lucky is that?

Here is the "O" ring and washer repair I made. In the first photo, you can see the steel washer in my right hand and the "O" ring around the threads of the plug in my left.. The second photo shows how the steel washer fits around the "O" ring and plug, making like a counter bore for the "O" ring.




So that's it.
I bolted everything back together and filled up the reservoir to try it out ... perfect... no leaks. Guess what, the steering works great now without intermittent hard turning like before.
LOL ... Another perfect job done in record breaking time.

 

[greg_g]

I admire your field expedience Rob. I read with interest to see if any of your descriptions might help me figure out the perenniel steering problem with mine. Unfortunately not, but it was an interesting read. Good job.

//greg//

 

[Diamondpilot]

Nice job on the field repair. I learn a lot from your post. I like it that you can look outside the box to figure things out and get it up and going again.

Chris

 

[3RRL]

Thank you Greg and Chris.
Making field repairs is so important for me since I'm in a very rural area of CA and of course, no Chinese Tractor dealers nearby. My "camp" workshop has almost as many goodies as my home garage shop. So I am very lucky to have some supplies that can be substituted for the original part.

Greg,
I know you've been suffering similar steering problems with your Kama. I'm wondering if that little set screw plug ... the restrictor might have worked it's way loose inside your pump? It screws in from the bottom, directly below the high pressure outlet so it seems to be a flow restrictor because of the small hole in it. If that is loose and floating around like mine was, it could lead to erratic steering behavior. I don't know for certain if that was the cause, but I ran my Kama for at least 6 hours after the repair and all that went away. I even refilled the reservoir with AW32 instead of AW68.
I have 466 hours on the meter now.

 

[greg_g]

Greg, I know you've been suffering similar steering problems with your Kama. I'm wondering if that little set screw plug ... the restrictor might have worked it's way loose inside your pump?.

I've had a hot weather steering problem since the tractor was new, but the symptoms are nothing like yours. And there's nothing erratic about mine, it's strictly temperature related. You even demonstrated the difference by being able to drop from AW68 to AW32. The only way to fix my hot weather problem is to go the other direction - all the way to AW220 (about 50W) during the summer. AW32 works just fine the other three seasons.

//greg//

 

[3RRL]

I wanted to revive this thread to report that the first 50 to 75 hours I had perfect performance after the repair.
But I have had on and off, good and bad performance out of mine since then. Exactly like the old symptoms, not like the power steering failure from the leak. I have 560 hours on the Kama now! Every morning the steering works like a charm ... smooth and free and light to turn the wheel. Goes lock to lock forcefully (positively) and holds, even under a heavy bucketful.

As it gets hotter, it gets harder and harder to turn like you've lost the power steering altogether. Then at some point it's like it "gives way" and starts steering light again, like the power steering kicks back on. So I don't think it's the cylinder bypassing or it would be bad all the time. And it wouldn't feel like a clog passed through, know what I mean? I run AW68 fluid in mine too (again). Fluid level is good and suction strainer is clean. I think it's debris that gets caught in the steering valve or somewhere.

After the repair, it must have left some remaining debris like part of that grommet in there that the strainer is not catching. So now it is back to the same old thing. Works good when first started and then when it heats up it stops working good. Then on occasion, it feels like a clog passes and starts to work good again, and then not... Larry told me he put a 10 micron filter on his steering system return in addition to the suction strainer, and I may do that too. Might help with this recurring problem I seem to be having.
Any thoughts?