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.

[GuglioLS]

Rob

Did you get to take the pump apart? are there any pressure relief setting in it? I know you've had trouble with this before. but never any leaking like this.

Larry

[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]

gugliols said:

Rob

Did you get to take the pump apart? are there any pressure relief setting in it? I know you've had trouble with this before. but never any leaking like this.

Larry

I only took the pump apart enough to fix the problem. There is another cap screw next to the one I removed. You can see it in the 3rd photo I posted. I didn't remove it because it took a larger metric size Allen wrench then I had in my set. But I'm thinking that could be a PR valve in the pump manifold itself, however I can't say for sure.
Rob-

[GuglioLS]

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

Well then did screwing that restrictor back in place solve those intermittent steering problems you've been having?
Looks like that sure could have been a problem.

How did you make a new seal for that plug?

Larry

[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.
Rob-

[psj12]

I have also had problems with the Chinese rubber covered seals, just not the one in that location yet. They really aren't Dowdy seals, as dowty seals are a metalic washer with a bonded O ring on just the inside circumference (much like what you fabricated). Dowty seals are what Chip supplies to replace the chinese rubber coated washers.
I have performed field fixes on some of mine by cutting the rubber away completly and coating the remaining metalic washer with pematex then tightening it like you would a copper or aluminum seal. This usually holds until the replacement arrives from Chip.
All the hoses going to the valves on my LW7 backhoe were sealed with these Chinese washers and had to be replaced along with some of the hydraulic seals on the main manifold under the tractor. I hadn't had the tractor running even an hour when the main pressure line to the main manifold blew the washer and I lost all the hydraulc fluid. I have not been able to find a dowdy seal that large and am still working with my field fix two years later.

[quikduk]

Great diagnosis and repair Rob! I need to call our dealers and see if a "kit" of specific sized Dowty seals is available or if they know the common sizes and places they go on our tractors.

[3RRL]

Thanks guys,
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.

Reinstalling that little set screw plug ... the restrictor that worked it's way loose inside definitely made a difference. 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. When loose and floating around like mine was, it could lead to erratic steering behavior. I don't know for certain if that was it or not, 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.
Rob-

[bradblazer]

Very nice job on the repair Rob! It is very valuable to me to see what to expect from mine in another 300 hours!

Brad

[3RRL]

Thanks Brad,
For some reason I believe you will get much better service and suffer less repairs than on my Kama 554. You are much more conscientious of how you treat your tractor than I am. I'm afraid to admit it, but I think intelligence has something to do with it.

Mostly though, if you don't absolutely beat the shit out of your tractor, there should be nothing to repair. That is not to say you can't use it to do normal tasks by any means. You can certainly work the crap out of it. But just don't over stress every feature on it like I did, and it should last a long time. IMHO, any tractor brand of the same size subjected to the same stresses and abuse I've subjected the Kama to would probably have resulted in similar breakdowns. I have done some stuff with my Kama 554 that is really incredible. Did you see the size of the boulders I popped out and grabbed in my Log Home thread?

The other little repairs like this one might be from inferior rubber or perhaps electronics? Also fitting or assembly problems and lack of quality control... things like that. They can be annoying but I guess I'll take them over paying an extra $20 grand up front.
Rob-

[mariner]

Hi Rob,

Yes, I think most of us will agree that a few hundred dollars spent on the occaisional repair is better than the $20,000 up fron as you say. Even the puchase of a not too old domestic tractor (say 5 or 6 years) can have it's share of expensive problems.

Sorry, didn't mean to hijack the thread - just wanted to say I agree with your reasoning.

mariner

[3RRL]

No problem at all Jim,
I think what you emphasized is the motivating factor all us Chinese tractor owners have in common. And I'm the one that started off on the tangent anyway. Sharing a repair like this often leads to "why" and I guess in some cases, some of that leads to the initial cost?

This repair (the leak itself) may very well have come using AW68 in the hydraulic reservoir, a thicker fluid than the AW32. Who knows? The loose flow restrictor set screw inside? That should have been installed correctly from the get go. So perhaps that floating around in there could have blocked the flow and caused excessive pressure leading to the leak? Compound that with the AW68 I put in and shazam, leak city. The more experience I get making these repairs leads me to think it's not just the materials being used in our tractors, but often the installation or quality control of the process.
Rob-