I was wondering if you can flip the wear plate on a schwing p305. It is a s-tube pump. I got my new one and the mounting bolt holes are tapered on both sides of the wear plate as if it could be mounted from both sides. Seems to me the only issue would be the wear on the wear plate on the cutting ring side would be against the material cyls. if ya were to flip it, would this hurt anything? hate to trash a part that could be fliped and used some more.

I know that Olin swing tubes spectical plate is reversible, tapered holes on both sides, flip it and the mud fills the wear gaps between the plate and hopper, if you are going through the trouble might as well change the cutting ring also. As I remember the cutting ring use to be reversible to.

I wouldn't see a problem if it fits. Redman I've got my 305 tore apart also. I took the upper hopper off and removed the S tube and bushings. I just ordered the new mud cups and pressure spring from Schwing. Someone said I had to take the whole bottom barrell off to get to the mud cups but other advice said I could just pull them out the hopper side ,so thats what I did. Have you ever changed yours? I guy needs to strip the hopper apart at least once a year to clean the grout out and inspect the rubbers, also just to keep the bolts and joints loose and lubed. I'm going to put a new pressure spring in but my cutting ring is very stuck I'll probably try heating it up.

I have changed the cups before and I did it like you said from the hopper. close the quarter turn valve, pump in reverse, and the pump will pressure out right at the end of the stroke just before it shifts and bam the cup is right there to pull out. I am getting different advice as to wheather or not I can flip my wear plate... going to get after it soon here, and I will see what things look like.

Redman, I looked at your pics of the rebuild. That center bolt is very important. That holds it all together, The other 4 bolts act as a key. If the center bolt is niot installed or loose, the pressure of the concrete in the tube  will spread the space between the front and back of the housing and the bolts will spread and he valve will separate from the shaft, waller the holes, and you will be replacing the shaft. Pretty spendy.

FYI

Redman, you can flip the spec plate on any pump. The problem with this, the wornside can not seal against the cylinder. There is an oring seal on every pump cylinder. If that oring can not seal, then there will be a vaccum leak and concrete will build up and choke up the output, and your volumn will be shit.

Try Bondo on the worn side, sand it smooth, and then get 2 times the life of the wear plate. Failure to do so will result in the exteme wear of the output end of thwe cylinder.

You can remove the cups from the hopper side. Be careful. Turn off the engine. Go to work.

 Use an impcct with 1-1/8th inch socket.

Remove the piston face, and piston cup.

Leave the support plate on the rod.

Reassemble parts with grease(lots) and never seize the bolt.