Power steering leak

[Paddy]

My KAMA 454 has had a leak on the power steering pump for some time. I though it might need a rebuild kit so installed the set. No change. It leaks only when turning, go figure!

Now I think I see where it's coming from. There are two plugs on the bottom, farthest section away from mounting face. These are pretty large plugs using a 1/2" alen wrench. How are these things sealed? Is it as simple on using pipe dope? Or do they have some Cu seal?

The lines are not leaking. I wiped them and they stay dry. Only the bottom of the pump is wet with oil.

Any help would be great

Paddy

 

[greg_g]

Never had the problem on my KM454, so I don't want to speculate. My steering leak was at the rubber coupler on the line the supplied the pump. But before you tear something up trying to remove those plugs, I had an interesting experience with one of my pickups. The PS pump had a chronic leak, likely a seal. I went through a whole can of PS stopleak, it ran out as fast as the regular fluid. But I had a partial container of transmission stopleak in the garage. Just for the helluvit, I topped up the PS reservoir with that stuff, and the leak stopped almost immediately. And permanantly.

//greg//

 

[Paddy]

Greg,

Sounds like a plan. the system only takes one qt, what ration did you use?
I have checked all hoes and lines. If not the plugs, maybe the housing has a crack?

 

[greg_g]

Possibly, or a seal. As far as ratio, in my case I filled the whole reservoir. Besides finding and sealing the PS leak, the transmission stop leak formula also acted as an effective PS fluid. Strange turn of events. Granted, the KM454 reservoir is considerably larger than that of a Ford pickup. But the stop leak isn't (or wasn't then) any more expensive than PS fluid. You're not out much if it doesn't work.

//greg//

 

[Paddy]

I replaced all the seals/gaskets. chip sent a factory rebuild kit. Though none of them looked bad. I'll try the stop leak but it really pours out at times. I will go through a qt in 2 hrs.

Paddy

 

[Bob Rooks]

Just a thought here, what are the sealing surfaces like on the shafts? Are they grooved? Might have to replace a shaft or install a Speedi Sleeve.

Wear sleeves - SKF.com / Products / Interactive Engineering Catalogue/Industrial shaft seals

 

[greg_g]

The other thing is viscosity. I originally used AW32 hydraulic fluid. From the git-go, my pump had a pressure relief valve issue. Mowing paddocks requires a lot of steering input, especially as you get near the end. In the heat of July and August - the steering got so hard I had to occasionally shut down the tractor for 30 or more minutes to let the pump cool down. Rather than take out the radiator to get at the pressure relief adjustment (it's under one of those plugs on the bottom), I switched to a thicker fluid. I tested various viscosities, eventually finding 50W racing oil eliminated the problem. But then came winter, and I had to wait too long for the 50W to thin out. The end solution was 20W50 engine oil, with no problems from that point on.

//greg//

 

[Paddy]

I have not put it back together but now I know what the plugs are on the bottom of the pump, presure relief valves. I'm pretty sure that is where it's leaking. that is, around the plug threads. Should there be preasure on the plug? or is it a cap to cover the valves? The plugs have a 12mm allen, just under a 1/2". I need to grind one of my 1/2" allen wrenches down a tad to fit!

As far as steering she has always steered fine, just leaks badly on hard/full turns. I can see a trail of oil only on curves in the road.

Paddy

 

[greg_g]

It's just a cap. The fact that it's leaking indicates the PRV isn't working. I'd be really surprised if the actual repair part was available though, you'll probably have to replace the whole pump.

It's a CBN06, right? I suppose you could take it apart and see if the problem is just dirt clogging the valve. But after all that work, it's probably just as practical to simply replace the pump.

..greg..

 

[Paddy]

Up date on the leak. It appears to be a Bonded seal on those plugs. Took the pump to a hydraulic shop and he said the seal is bad. He had a size larger and smaler, but not what I needed. hopefully Chip will have replacements. Looks to be 22mm id.

A bonded seal is a rubber gasket encapsulated in metal, rubber facing in.