hydraulic control valve in 443 leaks need advice

[443life]

merry christmas to everybody in SSF.. 443 has been good to me lately til now ive sprung a leak in the control valve somewhere... at first i thought it was the case drain line under the block so i removed it from the right drive pump and checked it, it looked ok.. so i suspect its coming from the relief valve or the plug ... so i guess my question is should i remove the relief valve and and the plug as is and just change the gaskets/rings on it or should i pull the whole unit out and service it while its winter time? im pretty mechanically inclined and my pops has been a mechanic his whole life.. the hydraulics have been working fine even with the leak it still operates well what would anyone here do? thx!

 

[443life]

right drive motor i mean* i have lifted the rops while the engine was running to check where it was coming from even operated everything slightly and couldnt see anything, so my guess is it only does it when its under load ..

 

[Tazza]

right drive motor i mean* i have lifted the rops while the engine was running to check where it was coming from even operated everything slightly and couldnt see anything, so my guess is it only does it when its under load ..

No reason why you can't try replacing the parts with it in place if access allows for it.

 

[SkidRoe]

right drive motor i mean* i have lifted the rops while the engine was running to check where it was coming from even operated everything slightly and couldnt see anything, so my guess is it only does it when its under load ..

If it is anything like my 440b, don't be surprised if your hoses are starting to expire. Pretty much everything else hydraulic-wise is indestructible (believe me, I have tried - LOL), but the hoses are a definite weak point.
Access is a real issue if you need to replace stuff in the bowels of these machines. I just did all my hoses and my belt tensioner - engine and pumps had to come out. That said, it is not too difficult.
The main control has to come out if you need to service any thing on it, still not a bad job.
HTH - SR

 

[bobcatguy]

When you lift or curl does it leak back down? I had a 863 (different beast I know) that would leak from the back side of the control spool. I was able to remove the spools without removing the valve itself but you have to be careful as one of the caps on the back of the valve have a small spring and ball that acts as the float lock when you press the left pedal all the way down and it locks in. Once I had the caps off and the spool removed I was able to put in new seals on the front and back and I believe there were also o rings on the back side of the valve but I not certain of that. I'd start by pressure washing and then trying to find where the oil is coming from.

 

[mmsllc]

When you lift or curl does it leak back down? I had a 863 (different beast I know) that would leak from the back side of the control spool. I was able to remove the spools without removing the valve itself but you have to be careful as one of the caps on the back of the valve have a small spring and ball that acts as the float lock when you press the left pedal all the way down and it locks in. Once I had the caps off and the spool removed I was able to put in new seals on the front and back and I believe there were also o rings on the back side of the valve but I not certain of that. I'd start by pressure washing and then trying to find where the oil is coming from.

I AM CURRENTLY RESEALING A BOBCAT 751 LOADER CONTROL VALVE. MY MACHINE WAS NOT AS EASY TO WORK ON BECAUSE OF ALL THE HARD METAL HYDRAULIC LINES THAT INTERFERE WITH REMOVING THE VALVE AS AN ASSEMBLY. I WOULD HAVE REPLACED THE SEALS WITH THE VALVE STILL IN PLACE, BUT THE FUEL FILL HOSE & CLOSE POROXIMITY / LACK OF ROOM DUE TO THE VALVE BEING TOO CLOSE TO THE FRONT BULKHEAD / HAND CONTROL AREA THAT WOULD NOT ALLOW IT TO BE DONE EASILY. I WILL SAY THAT RESEALING THE VALVE IS A VERY STRAIGHT FORWARD PROCESS, ESPECIALLY IF YOU REMOVE THE VALVE FROM THE MACHINE. IT IS NOT A FAST JOB. BUT IF YOU HAVE ENOUGH ROOM & THE AREA IS CLEAN, THEN YOU MIGHT BE ABLE TO RESEAL IT WHILE STILL IN THE MACHINE. JUST A WORD OF CAUTION, DO NOT REMOVE THE "C-CLIP" FROM THE LOWER SPOOL VALVE, JUST REMOVE THE ENTIRE SPOOL VALVE AS AN ASSEMBLY. (DOING SO WILL REMOVE THE CHANCE OF DISTURBING THE FEARED DETENT BALL BEARINGS EVERYONE MENTIONS!) DEPENDING ON THE AGE OF THE MACHINE & LEVEL OF MAINTENANCE YOUR MACHINE HAS GOTTEN IN THE PAST, IT IS A VERY GOOD IDEA TO REPLACE THESE SEALS DURING THE WINTER SEASON / SLOW TIME OF THE YEAR; SO YOU KNOW IT WILL NOT GIVE YOU PROBLEMS LATER ON WHEN YOU ARE IN THE BUSY SEASON. THE SEALS ON MY VALVE WERE SO OLD THAT THEY WERE ROCK HARD & NOT DOING MUCH IN THE WAY OF SEALING ANYTHING.