Ih 674 hydraulic problem

[Jstoll74]

I have a few hydraulic issues on my 674. Bought tractor as a fixer. Hydraulic pump was out and hadnt ran for years. I put new pump in went trough the mcv cleaned and checked that all is well. Everything seemed to work good then I put the loader back on. I had emptied the cylinders and blew lines out on loader before putting on tractor. I hooked the loader hydraulics up a port on the remote. Loader lift is slow and wont lift with bucket on. Power steering doesnt work well now. And if I even touch the steering wheel all other hydraulics stop working. Pto seems to work but havnt hooked anything up to it. Brakes are good. 3 points has symptoms of bad unloader valve. Raises with assistance of moving other levers. I took unloader valve out and cleaned and put new orings on it. Only problem is I couldnt get it all the way apart. Looks like I need a special tool to get last part of a valve out. I put back together without taking last part of valve out and still have same problems. Any help would be greatly appreciated

 

[caterpillar guy]

When you changed the filter did you wash out the screen in front of the filter? Did he valve sticking in the bore? If it is wrap some emory cloth around a stick or rod then spin it with a drill in the valve bore to hone it to remove any scratches or imperfections in it. Did you change the filter when you had the MCV off and is it sealed well around the gaskets with new o-rings especially the teflon ones. IT sounds like your priority valve is not working well or you would /should have steering whether the other works or not.

 

[Mrfred54]

You said all was well before the loader install. Do you mean all hydraulic functions were working??? After trying loader functions did you refill hydraulic reservoir??

 

[Jstoll74]

Yes full of fluid and new and new filter. I did take all valves apart on mcv and all appear to be smooth and operational.

 

[used red MN]

Hello Jstoll74 welcome to YT! I have no direct experience with your tractor model, but I do know these MCV systems can be finicky. Now that you had it all together with the new pump and contaminants have been circulated around and hopefully filtered out my thought would be to pull the MCV and run through another check on it just to make sure something did not make its way into one of the valves and stick it. Of course you can take my recommendation with a grain of salt and choose to use it or not.

 

[Highwayman]

The filter can be letting air in if the oring isnt seated properly and causes thd symptoms you described