MCconnell Marc 425 XL

Rich Waugh · Jan 20, 2014

I agree with Chris and erj - and will add that you need to drain your engine oil and replace it with fresh and a new filter. The reason your sump is over full is that the pump blew the seal and pumped hydraulic fluid into your engine sump.

RealMav · Jan 20, 2014

ok ,I am waiting for the plug to come. it is 30mmx2.0 .Also I want to get a new driver shaft that engages the pump ,it has been machined at 90 degrees with an new slot from previous owner having this problem. Thanks for all help, Ric
And yes I will change oil and filter.

RealMav · Jan 29, 2014

I put the plug in power beyond port and it made no difference in pressures. I also got a pressure relief valve to go in right after the pump in case of further issues. It is really working good right now but I will still put the new pump on when it gets a bit warmer out. I will leave power beyond off so the quick connect will not be an issue there. I also learned that loader down is float at full down control and letting off lever a bit and it has down pressure.

erj · Jan 29, 2014

RealMav said:
I put the plug in power beyond port and it made no difference in pressures.

Did you also remove that hose that was used for PB and plug the Tee input?

RealMav · Feb 1, 2014

I rebuilt the pump and it went to 1500 ,loader worked well but was leaking oil out the mounting plate at front of pump. I thought it was engine oil but seal on pump was pushed out again. I then put the new pump on . fel and tph and steering are working great but check out the spike at the end of travel. over 2500 lbs. I am guessing ,but seems like the pressure relief in the control valve should not allow this much pressure.: tractornew pump 014 - YouTube

quicksandfarmer · Feb 1, 2014

Yeah, that's too much pressure. That's probably what caused the first pump to fail. You are correct that the pressure relief on the control valve needs attention.

RealMav · Feb 2, 2014

I backed the fel prv back 3 1/4 turns and its much better now ,opens at about 1600. I still need to repair or replace the pump driver shaft and change the oil and filter again. It is coming together now and working good.

doxford jim · Feb 4, 2014

I would also install an aftermarket system relief valve on your tractor. I installed one on my machine because of two failures - both related to something in the TPH system. Have attached a c ouple of foto's of what did so that I am not relying on the tractor relief valves only. All that is needed is a bit of dirt or some metal shavings getting caught in the valve and the pressure in the hydraulic system is no longer controlled properly - don't ask how I know.

RealMav · Feb 4, 2014

thanks Jim, one of my next questions was going to be , why can't i put a tee in the fill plug and run system pressure relief there!. LOL awsume I already have everything but the tee to hook this up. is the tee before the prv for a gage?

doxford jim · Feb 4, 2014

The T before the PRV is only used to connect everything, but yes, the plug could be removed for a pressure gauge fitting if need be. My pressure gauge is connected to the valve control block on the loader support.
The PRV return to the hydraulic tank works well. Don't forget that with a hydraulic system - once the PRV starts to open the pressure drops drastically. Unless there is a large volume of oil opening the PRV, all that will pass is a small amount (whatever is required to relieve the prssure) and not full bore 1/2" pipe full. The other side of the tank T is the plastic hose vent that goes up the ROPS to the canopy and stops the mess from oil coming out of the dipstick tube vent holes.