Abbey Slurry Tank - Front ball valve assembly not allowing suction? (See Photos)

Do you think i should open this assembly?

Thanks. I didn't know if I would be affecting the pressure gauge at the top of the unit by opening the assembly. I was tempted to take off nut no.2 but I didn't know what was making that pressure gauge work, and if taking off the cover at the bottom would break the pressure gauges operation.

That's correct. There is a rubber seal. it. I'd imagine after putting the cover back on afterwards the seal would not be as good as before but i'm sure it would still be 90% good.

What can i expect when i take off that cover, is there a ball inside that i will be able to push up and down to check that it is moving freely?

Do you have any idea why this ball valve assembly would allow air to be blown out into the tank but not allow air to be sucked in?

When this issue first arose, i assumed the black pipe leading from the engine unit to the ball valve assembly was the problem as it was significantly damaged. So i replaced this black hose but the same problem persisted. You can see it is a brand new hose in the images i provided.

It may well have been a piece from the old hose that got sucked into the ball valve assembly unit that has caused the problem. Hopefully all that is required to fix this problem is to take out what ever bit of rubber from the old hose that got sucked into the ball valve assembly. You are worrying me saying the ball might have turned oval shaped. That sounds like i would need a new ball, or worse yet would need to replace the entire ball valve assembly unit which would probably cost €200 or more i presume.

As you can see in the images, i have removed the upper black hose. I then tested to see if the outlet from the ball valve assembly was sucking and blowing from that outlet. And it would only blow outwards but would not suck in. That is how i was able to narrow down the problem to the ball valve assembly unit. I had previously tested the engine separately and found that it was both sucking and blowing correctly. So no stuck veins or anything like that.

Is there any type of grease i should put on the ball to ensure it moves freely in future? I was going to put WD40 on it but was worried that might damage any seals or something inside the assembly unit. Not sure how corrosive WD40 is.

Perhaps some good old tractor grease would be handy to rub all over the ball?

So I took off the bottom cover of the ball valve assembly unit. I was hoping to find something blocking the ball from moving freely but found nothing.

I was surprised to find the ball valve assembly unit has an upper and a lower chamber. I cant see what is going on in the upper chamber but the lower chamber is where the ball moves up and down.

The ball is rubber but has a hard inner core which you can feel when you press the rubber in. As I cant see anything wrong with the ball valve assembly unit itself, the only thing I can think of is maybe the hard inner core of the ball might be gone slightly oval shaped. To look at the rubber ball it looks perfectly round but on squeezing it there might be a very slight oval shape to the inner core.

Do you think that might be at the root of the issue as to why the tank will blow fine but not suck?

No. The pump is blowing and sucking fine. Nearly sucked my hand into the pump. Huge suction. Won't be putting my hand there again. The problem seems to be the ball valve assembly unit directly over the pump. But I opened that and no obvious problem found there.

I dont know what is in there at all, but there is no way to open the top chamber of the ball valve assembly unit. It is a closed unit, welded closed from the factory. The best i can do is stick my hand up from the lower chamber into the upper chamber and have a little feel around there but there appears to be nothing like a ball up there at all.

There is another unit that sits on top of the tank itself. I have no idea what is in there.

But i did test the outlet pipe from the ball valve assembly unit directly over the pump and the outlet would allow air to be blown out but would not allow air to be sucked in. From this i concluded that i had narrowed down the problem to the ball valve assembly unit directly over the pump.

One other point i should make is that when i first turned on the spreader, and i did this on two separate occasions, the tank would blow air out the back but after moving the pump handle into the suck position and then go back and put it in the blow position, now for some reason the tank would no longer blow air out the back. So there is an aspect here of this being an intermittent problem.

This makes me wonder if the ball is not perfectly round and so is positioning itself in such a way that it will work sometimes but not other times. Also the inner surface of the ball valve assembly unit is dirty. Not excessively so, but still a bit dirty. This makes me wonder if i gave the inner surface of the ball valve assembly unit a good clean perhaps this would allow the ball to move more freely up and down the chamber.

I included pictures of my tank in the opening post on page 1 of this thread. The layout of my tank sounds different from what you are describing.

I didn't know you could see the ball by simply shining a light in the back of the tank. So i wouldn't have to crawl into the tank itself? The hatch at the back of my tank is quite small, i dont think i could squeeze in and crawl into the tank itself to inspect the ball from underneath. I'd also be weary of doing this as there could be fumes inside the tank.

Is it possible the bar has rotted like you say and the ball has fallen into the tank itself and rolling around inside? I'd imagine this would make no difference to sucking and blowing. I'd imagine those balls are only to stop slurry being drawn into the pump, but i tend to only ever half fill my slurry tank so i don't think this would ever be a problem. The slurry would never get as high as the roof of the tank.

One thing that confuses me about the ball valve assembly unit at the front of the tank is that when the pump is in the sucking action, from what i can see the rubber ball should be sucked up the ball valve assembly unit and seal the hole at the top of the ball valve assembly unit. I would have thought this would make the pump unable to suck any more air as the rubber ball would be now acting as a blockage.

So how is the pump able to continue sucking air, and hence sucking slurry into the tank at the back, if this rubber ball is acting as a blockage?

Oh ok. That makes sense. I thought that the ball was going up and down the metal tube depending on whether the pump was sucking or blowing. From what i understand you are saying, the ball would stay at the bottom of the assembly at all times except in an emergency when slurry accidentally got sucked into the assembly and only then would the ball rise as the slurry rose inside the metal tube to where it would stop at the top of the assembly unit and cut off the slurry from going any further, in other words into the pump itself.

When i opened the bottom cover of the ball valve assembly unit, the ball seemed quite tight in there. It took me a while to lever the ball down and out of the assembly. Is it supposed to be that tight?

I dont think its rust. There is a bit of crud but not enough to make the ball tight.

Is it possible the ball has swelled? The ball is squishy to feel, as though it is full of air, and after pressing it in about 5mm all around i can feel the hard inner core, but the rubber outing pushes back out again. Just like you would squish a balloon and after you let it go the balloon pushes back out again. So the ball seems to be a sealed unit that is undamaged since it left the factory.

I had to push a long screwdriver up to lever the ball down the tube and even this took me several attempts. The outside of the rubber ball is making contact, all the way around, with the inner surface of the metal tubing of the assembly.

That's interesting. I must take it to my dealer. I have no experience with what these balls should feel like.

Though its puzzling me as to why the tank is able to blow air out the back fine, but wont suck air in at all.