7245 hydraulic upgrade

[maximus]

Im looking to repair my weak hydraulic pump. Do i just replace the internal pump or has anyone retrofitted the old internal pump to a new style engine driven pump?

 

[Renze]

engine driven pump, means you need an SAE PTO on the engine timing gear. a 7245 doesnt have that.

Its best to upgrade from the 20l/min pump to the 32l/min pump, both fitting in the same space under the diff housing.

 

[maximus]

hey renz do you think the new pump that you speak of will give me the performance im looking for from my loader and will it last?
Also where do you suggest i should buy it from Zetor or aftermarket? Thanks

 

[Renze]

32 liter per minute gives acceptable performance on my loader with 63mm (2.5") cylinders. My current tractor has the original 20 liter pump but it will change next year to 32l too.

They are available both aftermarket imitation, aftermarket original and original from Zetor . the quality of the aftermarket Hylmet pump from Poland is quite good, but for the price difference i 'd perhaps choose original (from a wholesaler) the next time.

In the USA i would try http://www.ridgewaytractorparts.com/

 

[askinner]

I have upgraded the pump to a crank driven one. The front pulley has bolt holes for a front PTO, I made an adapter plate from a big washer, and used a pump drive shaft off a ford 550 backhoe. I removed the old pump and made a plate to replace the original one, and mounted a 1.5" suction line and screen in it. Took some doing mind you, but I am now putting 80LPM through it, which I need for loader work and opening and closing the tailgate on the baler fast.

 

[Renze]

i wouldnt take the pump out the rear end, because 80l/min has way too much restriction in the 3pt valve. i would keep that for the 3pt and use the big pump with big valve blocks for the front loader and external hydraulics. On the Forterra 70l pumps would blow due to too much restriction in the return flow when the pump wasnt operated.

 

[askinner]

No overheating so far, the hottest it has got is 70*c, which considering we had a 46*c day here yesterday, is pretty good. I took the pump out of the rear end, as I was sick of paying the $1000 odd AUD to replace it.
I was running 60LPM to start with, so I can go back to it if I have overheating dramas, but I will add a hyd cooler before that happens

 

[Renze]

I wasnt talking about overheating, i was talking about premature pump wear.

 

[askinner]

Checked back pressure, 300psi, so no chance of that. The pump is a rexroth unit, much better quality than the zetor pump. People running their pump on 1000 pto rpm will wear theirs out quicker, I haven't worked out what the speed is on 1000 pto, but judging by the scream out of it, it must be way too fast.

 

[gav]

most 7711/45 had front mounted pumps off the crank pully ..worked ok apart from the coupling claws being alloy and wearing out ..can't remember the output of the pumps but seem to think they were 75-80 litres ...never had any problems with oil temp and they didn't have any coolers fitted ...as such

 

[Renze]

..can't remember the output of the pumps but seem to think they were 75-80 litres ...never had any problems with oil temp and they didn't have any coolers fitted ...as such

If your pipework is big enough to take the flow, its no problem.