7745 new hydraulic pump

[reco31]

Hello again everyone,
3 point hitch very slow, loader very slow, opening round baler off the rear remotes very slow/weak. So we changed out the hydraulic pump, we also replaced the 2 "O" rings in there got it all together and everything seems the same. Any input would be appreciated.
Thanks

 

[ixer0]

Hi,

You did find and clean the suction filter on the pump plate didn't you?

Mike

 

[reco31]

Hey Mike,

Yeah first thing, cleaned magnet and mesh filter.

 

[forterra9641]

did you replace the relief valve? if the pump is badly worn metal shavings goes inside relief valve the symptoms you descrbe.

 

[reco31]

No we didn't change the relief valve because our neighbor has the identical tractor with identical problems a few years ago and all he did was change the pump and he was back in business. I should have listened to my gut and replaced the valve too, ah well, not a hard job to drop the oil and the plate to access everything. Thanks, I'll give it a shot and let you know what happens. Also, when checking the oil level there are tons of tiny bubbles in the oil like something is blowing there.

 

[ixer0]

Hi,

It sounds like you have a blown o ring or a split pipe. There are 2 small o rings where the top cover goes on, like the 2 on the pump plate stand pipe. Relief valve wouldn't give you slow action just weak lift. Look for a leak.

Mike

 

[reco31]

Hey Mike, thanks for reply, hmm I'm having a tough time picturing where those "O" rings are. I replaced two on the pipes.

 

[Renze]

Hey Mike, thanks for reply, hmm I'm having a tough time picturing where those "O" rings are. I replaced two on the pipes.

pull the pipe out to find the other O ring. Its a short piece of pipe with two o rings on it, when taking it apart it splits on one end and the tube sticks out on the other...

 

[reco31]

Hey guys, finally got the pump down and where there is a small pipe sticking up around the edge of the base with 2 O rings on it I saw something almost totally blocking the hole down below? I took the end piece off where the external hose attaches and there was a half inch threaded plug? Now should this plug be threaded all the way in or does it need to be in there?? Could this plug be the cause of all my headaches?

 

[reco31]

Looking at it further it appears the plug may have been used to divert some flow or that was the intention?? Pressure outlet out of the pump after overload valve has an exterior half inch street elbow threaded into the bottom of the plate with a hose going to the "block" under the tractor, the second line comes from the side of the plate to a hose also going to the block under the tractor (this is where the plug was threaded into) and a third exit which is the small pipe with O ring that seats to the internal hard pipe when plate is re-assembled to the tractor. I'm not sure where the internal "hard" pipe goes? Should all 3 pressure "exits" have full pump pressure? What the heck is that plug in there for??????

 

[Renze]

There should be only a steel line from the pump yo the plate. Oil is pumped through the small pipe with o rings, to the valves in the 3pt cover.

 

[reco31]

Inside the tractor yeah, one line, but I was referring to the lines on the exterior of the pump plate that feed the hydraulic control valve for the loader and rear remotes.

 

[reco31]

Anywho, we're back in business. Previous owner drilled and tapped into the pump plate to feed control block for the loader and rear remotes and the then piped the continuous flow through said block back into the pump plate to feed interior steel line. So that plug was in between the exit and entrance of the oil flow. Just had to thread the plug in maybe 2 or 3 cm (it had back out and was blocking the return hydraulic oil) to fully separate the 2 and works great.