Sounded like a shot gun

[Max in Mich]

"56 F40 with about 10 hours of run time since reassembly. Hydraulics have not been working correctly. Today I started the tractor with the control lever in the down position and the lower arms raised. At the top there was a loud "pop" that sounded like a shot gun. The arms dropped immediately. There is no movement at all. Where do I start?
 

[Tony in Mass.]

You will be lucky if you didn't crack the cover, see the loose bolts on the cover? leave the seat on, gives the loader something to tie onto, and balance, the cover has to come straight up, the levers are something you don't want to break off, or you will have to fish broken peices out of the base. The piston, or cylinder or rings- whatever you find is broken, is for sale on this site. The reason it - something broke is the pressure...? regulator? valve? I hope someone reads this and helps with the right wording, but most likely that is a safety valve that didn't work. You got a manual?







 

[Inno]

When mine went it was a cracked cylinder, it's not always the cover but often I hear that it is.
Definitely get a new pressure relief valve, I rebuilt my hydraulics but didn't put in a new valve. It's cheap insurance for sure, I think they're around 20 bucks. So a $20 part cost me over $100.........that hurts!
 

[Dan S (NY)]

This happened to me on a MF50. Follow the link...
Another bang...

 

[John(UK)]

It does sound like something has dropped into the Pump and that is what the bang would be. If there was nothing on the 3 point at the time then there would be little pressure in the system to cause any damage, so it does seem to point to something dropping into the Pump.
The top needs to come off to see exactly what has happened. If you need the information about doing this and repairing it, email me at the address below and I will send it...John(UK)...fergusontractors@hotmail.com