B1750 update,next step?

[al m]

So I got the new to be b1750 home,and as expected hydrostatic slows down after a short time mowing. I changed the hydro oil and filter,no improvement. No surprise but was worth a try I guess.
I have downloaded a workshop manual .
What's the logical next step?

 

[North Idaho Wolfman]

Are you 100% sure it's the hydro and not the clutch slipping?
A rear PTO driven implement will slow down with the tractor slowing if it's the clutch, you can also confirm this by removing the covers and watching the input shaft rotation compared to the speed.

If it is the hydro, starts splitting it and tear into it.

 

[al m]

Are you 100% sure it's the hydro and not the clutch slipping?
A rear PTO driven implement will slow down with the tractor slowing if it's the clutch, you can also confirm this by removing the covers and watching the input shaft rotation compared to the speed.

If it is the hydro, starts splitting it and tear into it.

Thanks
I watched the shafts,clutch is not slipping,tractor behaves the Same in forward as reverse,when warm it will not climb a grade or forward or reverse. I am assuming this rules out check valves. What can I do to determine if it is the charge pump or the hydro?

 

[North Idaho Wolfman]

I would pull the HST suction screen and see what you find there.

 

[al m]

Thanks Wolfman.i had planned on pulling the suction screens today,but two issues. One,I can't find the serial number on the tractor,so not 100% sure wher to find the suction screen.im guessing it's behind the banjo on the right side (f ok the seated position !looking forward)of the hydro,and that brings the second issue,what size wrench? 1" almost goes on,makes me thing 25mm,but I don't have one and can't find one to buy

 

[North Idaho Wolfman]

The one on the right rear is the Hydraulic loop filter.
The HST filter is just to the left.
I would also pull the spin on and cut it apart to check for anything in there too.

It has 2 hydraulic loops, the Hydraulic pump and loop has nothing to do with the HST pump and loop, they just share the same fluid.

Hydraulic loop filter:

HST loop Filter:

 

[al m]

Thank you,much appreciated,if the weather permits I will do as you suggest tomorrow

 

[al m]

Been raining here all day so not good for wrenching on tractors outside. I did go out,took off the side panels,soaked the entire tractor down with simple green,then after it sat awhile I pressure washed everything,including the hydrostatic and the tranny cooler. Started it up so it would warm up and dissipate the moisture off the starter and alt. Couldn't help but take it for a spin. Was surprised,it spun the tires right away. Thought I might be because of wet grass.took it to the small grade it would not climb yesterday. It made it up.in fact it can be stopped mid grade,the will proceed to climb.I am sure it should be much stronger but a definite improvement. I took the fill cap Off the tranny and looked in,a layer if bubbles about 1/8 or more on top of the oil,so I'm thinking its sucking air,causing cavitation

 

[al m]

I'm struggling here lads,have the oil drained again,it's what I'm going to call air entrenched,foggy with tiny bubbles. For the life of me I can't get the strainer to break loose,had a 3' cheater pipe on the breaker bar,socket slipped off and now its rounded over thinking of dumping the old oil in ,moving up beside the house so I can weld a nut on the end of the strainer and try again. Can't imagine why it's so tight

 

[al m]

Well boys and girls,took some extreme effort,bit got the strainer off. Pushed the tractor up beside the house wher I could throw the cables out the window,found a old 12 point 1" socket I could hammer on and carefully tacked it in for places with 6013. Leaned on it with the breaker bar and 3' pipe,broke the tacks. Grabbed some 7018,turned up the heat and welded her solid,this time the snap was the strainer breaking loose! What I found was the screen pretty smooth with a black film and some metallic sparkles. Used a telco pic magnet I have,probed the inside I'd the hydro,then vibrated the screen in a ultra sonic filled with simple green. Probed the tank with the same magnet. Magnet is hairy with some flakes,largest being about 1/16 in dia,hammered flat. I also found both clamps on the straine tube busted,replaced them.I reinstalled the cleaned strainer,with fresh o rings and filled the oil,slight improvement,will chew sod in low gear up against a tree after its warmed up but only squeals in high attempting the same test. Looks like it's time to split the tractor and dig deeperwill have to rearrange the garden shed,don't want to do the spit outside

 

[Shelbygt660]

Interested to know the outcome

Sent from my SM-G930W8 using Tapatalk

 

[North Idaho Wolfman]

It's actually non magnetic material that you would find in the screens if it was an big issue.
Before jumping into tearing it down, you might want to revisit all of the rubber hose connection and hard lines on the unit, if it has a leak on the suction side of the main pump or the HST it would suck in moisture and air and that wreaks havoc on the system operation and performance.

 

[al m]

Thanks for the tips and encouragement. I think I'll replace the rubber portion of the suction line and used a couple high quality clamps. Also in the market for some o rings. Just concerned the damage is already done and preparing by searching out used parts. More difficult to come by up here,north of the border.

 

[al m]

Have the tractor split and the hst out and tore down. Frankly I expected to see more damage inside.biggest issues seen to be the brass sides of the valve plates have grooves several thou deep worn into them,and the bearing and seal on the output side of the charge pump need replacement. Most Orings seem quite hard. I'm going to try and lap the grooves out of the valve plates,and replace the one bearing,seal and the Orings. Any comments on resurfacing the valveplates?

 

[jkk04]

Have the tractor split and the hst out and tore down. Frankly I expected to see more damage inside.biggest issues seen to be the brass sides of the valve plates have grooves several thou deep worn into them,and the bearing and seal on the output side of the charge pump need replacement. Most Orings seem quite hard. I'm going to try and lap the grooves out of the valve plates,and replace the one bearing,seal and the Orings. Any comments on resurfacing the valveplates?

Hi Al m.
I have read your threads since beginning because having same issue on my tractor b1750d.
Would you please upload some pictures for hst?
Will be much appreciated.
Thank you
Jkk

 

[al m]

Trying to post some pictures

 

[al m]

Seems I can only add one pic at a time

 

[al m]

And another

 

[al m]

Last for now