Engine trouble

[Jeremy Graham]

Hi, my M4500DT has started popping the oil dip stick out and hydrolics don't work unless I take off the oil cap. Is this blown cylinder rings letting air into the oil sump?

 

[North Idaho Wolfman]

Sounds like you have a dead headed hydraulic pump and a blow seal on the pump.
The engine having issues will not affect the hydraulic system, but the hydraulic system will affect the engine.
Check the oil level in the engine, if it's up, there is your issue.
Check the vent pipe coming off the valve cover if have a pressure issue that vent pipe is plugged.

 

[Jeremy Graham]

Sounds like you have a dead headed hydraulic pump and a blow seal on the pump.
The engine having issues will not affect the hydraulic system, but the hydraulic system will affect the engine.
Check the oil level in the engine, if it's up, there is your issue.
Check the vent pipe coming off the valve cover if have a pressure issue that vent pipe is plugged.
View attachment 152859

Thanks. I'll check it out. That would save me a few days work.

 

[Jeremy Graham]

Sounds like you have a dead headed hydraulic pump and a blow seal on the pump.
The engine having issues will not affect the hydraulic system, but the hydraulic system will affect the engine.
Check the oil level in the engine, if it's up, there is your issue.
Check the vent pipe coming off the valve cover if have a pressure issue that vent pipe is plugged.
View attachment 152859

I had a look and your advice was spot on. Thank you for your help. Brilliant!

 

[Russell King]

So now you have to replace the pump seal and figure out what is causing too much pressure in the hydraulic circuit!

Do you have any ideas on the hydraulic circuit problem? Anything changed or anything added to the circuit?

My engine oil level was constantly rising but the hydraulic system worked fine when the seal went out on the hydraulic pump on my L185 a few years ago. The only hydraulics was the 3 point hitch so there was no over pressure just wear from time.

Good luck