old press brake hydraulics

[metaltechinc]

I have a question. I have an old hydraulic press brake that is having issues. I have no schematics for it. It was made in italy and after they made it, they must have gone under. It has served us well for about 15 years. A couple of days ago we heard something up on top by the tank and then the pressure dropped to 500 psi. I need 1500 just to lift the ram. It can push over 5000psi. It has an external motor coupled to a hydraulic motor inside the tank. After looking, found it had destroyed the coupler, which is what I think they heard. Got it replaced and still nothing more than 500. Decided that since the valves had been dripping, might as well put seals everywhere that I can. I have not done all of them, maybe 75% of them. Still nothing. I am an engineer, but not well versed on hydraulics. I have pics of the valves. If anyone is interested in helping me through this, I can send pics and basically what it needs to do.

 

[HPost]

You need to pull the pump and have a look inside it.

It’s likely that coupling broke when the pump torque went up.

Check the pump...

 

[metaltechinc]

I have pulled the pump and replaced the coupling. Motor appeared in good shape. Very clean.

 

[HPost]

With respect, do you know what you are looking for in terms of the pump? A clean pump does not indicate a good pump necessarily.

If the pump is in good shape, then by the sounds of things, there is a relief valve or other valve that is stuck open and preventing the machine from building pressure.

Out of interest, what type of pump is it?