Blown hydraulic pump on ford 3400

preddster · Mar 23, 2011

I have a ford 3400 that the hydraulic pump cracked on the bottom back when it was cold. So I thought It might have had some water in it and frozen and cracked. I had it welded and it has ran for a few weeks with a small drip. I fired it up the other day and pulled up the cylinders on the backhoe and it blew the pump again with the old crack reappearing. Now that I think about it the first time it happened I believe I was pulling up the cylinders on the backhoe part. So might my relief valve be failing? I had the idea of putting a relief valve either between the pump and the control box or on the box itself where there is a cap you can take off and hook up a gauge to check pressure. I don't know much about hydraulics and am just trying to learn. I have the service book for the backhoe. I just wanted to get up and running again and wondered if the inline relief valve would protect my pump if the other relief valve failed.

J_J · Mar 23, 2011

First, get a hyd gage and have it handy for test and trouble shooting.

Which relief are you talking about. If it has a FEL, there should be one on the FEL valve. There should be a relief on the BH. However if you want to protect the pump independent of the valves, you can install this before any valve.

https://www.surpluscenter.com/item.asp?item=9-6135-50-H&catname=hydraulic

preddster · Mar 23, 2011

Strange you should post that relief valve from that company. That is the very one from that retailer I was looking at.

Soundguy · Mar 25, 2011

shopping for answers eh? didn't like the first ones you got??? you've already been told about this issue from many others.

the crack had a poor 'fixing' cance and a relief likely isn't your issue now.. it's a new pump issue.

soundguy