Should My Hydraulic Pump Internal Parts Look Like This?

Titan17

Member

Equipment
L3901 TLB, Caroni RFM, Scag Wildcat ZTR, Piranha TB,York RE 96", MTL HD 48" grap
Jan 13, 2019
92
6
8
Uncasville, CT
B1750 gear drive with 640 original hours. Bought this tractor recently from a friend. Hours are correct but hyd. Oil never changed or screen never cleaned.
Tractor is loosing hyd. pressure both at the loader valve and the hydraulic block (1500 psi when cold drops to 500psi when hot). Needless to say nothing is working correctly.
I inspected pressure relief in hydraulic block and loader valve, replaced O rings, confirmed both reliefs are not contaminated.
I'm waiting on components (BSP banjo bolt and adapter, manual needle valve for fluid bypass) so that I can isolate just the pump for an accurate pressure test.
I figured I would dismantle pump in the meantime to replace rotary seal and look for anything abnormal inside. I'm posting pictures. Doesn't look good to me but another opinion would be helpful. Most notable are the bronze end plates being scored.
Again the filter screen was badly clogged and the hydraulic oil runs very hot
I will probably buy a new aftermarket pump from Legacy Hydraulics and a new loader spool valve from Summit.
The pump is a left hand from what I gather..
Any other recommendations on loader valve and pump?? OEM is out of the question because on price. I will turn this into a strictly mowing tractor before I spend that much $$$
 

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JerryMT

Active member

Equipment
Kubota M4500, NH TD95D,Ford 4610
Jun 17, 2017
528
156
43
The Palouse - North Idaho
B1750 gear drive with 640 original hours. Bought this tractor recently from a friend. Hours are correct but hyd. Oil never changed or screen never cleaned.
Tractor is loosing hyd. pressure both at the loader valve and the hydraulic block (1500 psi when cold drops to 500psi when hot). Needless to say nothing is working correctly.
I inspected pressure relief in hydraulic block and loader valve, replaced O rings, confirmed both reliefs are not contaminated.
I'm waiting on components (BSP banjo bolt and adapter, manual needle valve for fluid bypass) so that I can isolate just the pump for an accurate pressure test.
I figured I would dismantle pump in the meantime to replace rotary seal and look for anything abnormal inside. I'm posting pictures. Doesn't look good to me but another opinion would be helpful. Most notable are the bronze end plates being scored.
Again the filter screen was badly clogged and the hydraulic oil runs very hot
I will probably buy a new aftermarket pump from Legacy Hydraulics and a new loader spool valve from Summit.
The pump is a left hand from what I gather..
Any other recommendations on loader valve and pump?? OEM is out of the question because on price. I will turn this into a strictly mowing tractor before I spend that much $$$
Looks bad for only 640 hours. Is there a rebuilding kit available?
 

JerryMT

Active member

Equipment
Kubota M4500, NH TD95D,Ford 4610
Jun 17, 2017
528
156
43
The Palouse - North Idaho
Looks bad for only 640 hours. The gears show wear also. My guess is that the plugged screen made the pump operate way off design efficiency and that means the oil will get pretty hot. May have caused the oil to breakdown and caused all the wear on the brass and the gears. Was their any indication of water in the oil? If the oil was contaminated that would not only cause the oil to not lube properly but it could cause the crud that plugged the screen.I don't know if it's rebuildable or if parts are available. Otherwise a new pump is in your future.
 

hagrid

Well-known member
Lifetime Member

Equipment
K1600GTL, ZX-14R
Jun 11, 2018
944
1,246
93
Pittsburgh
Your pump is shot. The wear pattern is from contaminants.
 

Titan17

Member

Equipment
L3901 TLB, Caroni RFM, Scag Wildcat ZTR, Piranha TB,York RE 96", MTL HD 48" grap
Jan 13, 2019
92
6
8
Uncasville, CT
No kits available. No water in oil. Just never changed
 

Titan17

Member

Equipment
L3901 TLB, Caroni RFM, Scag Wildcat ZTR, Piranha TB,York RE 96", MTL HD 48" grap
Jan 13, 2019
92
6
8
Uncasville, CT
Lots of rubber on screen, lots of fine metallic in oil. I bought the tractor for a cheap price knowing of hyd. issues
It looks and runs like a 2 year old tractor otherwise.
I've done 1 drain and refill, ran for an hour and will do another including all lower plugs before new pump goes in. Should I do any additives or super udt2 verses straight UDT. It won't get winter use.
Last questions.
I'm sure others have used aftermarket pumps. Legacy Hyd. sells a European made, could be German or Italian, 1 yr warranty, good customer service so far.
They know the difference between L and R. Has anyone gone this route??
RE: loader control valve. Summit sells a 2 spool with float for $250. It's manufactured by Brand Hydraulics and I believe it requires a power beyond adapter which they sell.
Because it's more $$ it should be better than eBay or Amazon options. Is that assumption correct or am I wasting money??
I got to this point with advice from oldhokie and thanks to everyone else for their time/replies.
 

TheOldHokie

Well-known member
Lifetime Member

Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
8,928
4,668
113
Myersville, MD
windyridgefarm.us
Lots of rubber on screen, lots of fine metallic in oil. I bought the tractor for a cheap price knowing of hyd. issues
It looks and runs like a 2 year old tractor otherwise.
I've done 1 drain and refill, ran for an hour and will do another including all lower plugs before new pump goes in. Should I do any additives or super udt2 verses straight UDT. It won't get winter use.
Last questions.
I'm sure others have used aftermarket pumps. Legacy Hyd. sells a European made, could be German or Italian, 1 yr warranty, good customer service so far.
They know the difference between L and R. Has anyone gone this route??
RE: loader control valve. Summit sells a 2 spool with float for $250. It's manufactured by Brand Hydraulics and I believe it requires a power beyond adapter which they sell.
Because it's more $$ it should be better than eBay or Amazon options. Is that assumption correct or am I wasting money??
I got to this point with advice from oldhokie and thanks to everyone else for their time/replies.
  1. In that tractor there is no benefit from the added cost of UDT/SUDT2. Any premium UTTO will be just fine.
  2. Very little difference in quality in gear pumps and Kubota prices are insane. Here is a GPO120L from White House Products - $125 delivered to the USA. Probably the exact same pump Legacy is selling for 3X that.
  3. The Brand valve sold by Summit comes with a 90 degree power beyond sleeve.

Dan
 
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Titan17

Member

Equipment
L3901 TLB, Caroni RFM, Scag Wildcat ZTR, Piranha TB,York RE 96", MTL HD 48" grap
Jan 13, 2019
92
6
8
Uncasville, CT
  1. In that tractor there is no benefit from the added cost of UDT/SUDT2. Any premium UTTO will be just fine.
  2. Very little difference in quality in gear pumps and Kubota prices are insane. Here is a GPO120L from White House Products - $125 delivered to the USA. Probably the exact same pump Legacy is selling for 3X that.
  3. The Brand valve sold by Summit comes with a 90 degree power beyond sleeve.

Dan
Dan.
I thought the same on udt/super udt. but didn't dare say it lol. I got a good education from you on this entire repair. You also saved me much $$$. I thank you again. I now will have much of what I need to do some hyd p. tests in the future.
I'm going to order pump now. Jim
 
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Titan17

Member

Equipment
L3901 TLB, Caroni RFM, Scag Wildcat ZTR, Piranha TB,York RE 96", MTL HD 48" grap
Jan 13, 2019
92
6
8
Uncasville, CT
New pump arrived today. Ordered it Monday morning 5:30 am est. DHL delivered Wednesday afternoon at 4:30 pm from Whitehouse Products Ltd. In Great Britain.
This pump was $330. Less than the cheapest one on eBay, $210. less than Legacy pumps here in the US, $575. less than Kubota. And they'd probably all drop ship from Whitehouse!!!
I'll do another flush on fluid, check screen again and hook up my guage for pressure check.
New loader valve from Summit arrives next week.
Thks for everyone's 2nd opinion, and especially O. H. for the tip.
 

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TheOldHokie

Well-known member
Lifetime Member

Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
8,928
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113
Myersville, MD
windyridgefarm.us
For some reason WHP likes me. Maybe because I registered as a business. When I checked last week the price on that pump delivered to my shop was $127 +/- . Thats in my cart and ready for a credit card number. I actually purchased one (by accident) a year ago and it was less than that. Maybe I should be in the middleman drop ship business.

BTW - Summit seems to he out of those valves again. Thats a really good price.

Dan
 
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Titan17

Member

Equipment
L3901 TLB, Caroni RFM, Scag Wildcat ZTR, Piranha TB,York RE 96", MTL HD 48" grap
Jan 13, 2019
92
6
8
Uncasville, CT
For some reason WHP likes me. Maybe because I registered as a business. When I checked last week the price on that pump delivered to my shop was $127 +/- . Thats in my cart and ready for a credit card number. I actually purchased one (by accident) a year ago and it was less than that. Maybe I should be in the middleman drop ship business.

BTW - Summit seems to he out of those valves again. Thats a really good price.

Dan
 

Titan17

Member

Equipment
L3901 TLB, Caroni RFM, Scag Wildcat ZTR, Piranha TB,York RE 96", MTL HD 48" grap
Jan 13, 2019
92
6
8
Uncasville, CT
The pump was 173. Delivered. Which was 330 less than eBay
But 127 is really low. At this point I was happy to pay them 173. Of that 35 was shipping.
Summit said next week with luck.
I'm going to see how the loader and 3ph behave with good psi and the stock shims in the loader relief valve. I'm expecting it to be about 1900.
 

TheOldHokie

Well-known member
Lifetime Member

Equipment
L3901/LA525, B7200DT/B1630, G2160/RCK60, G2460/RCK60
Apr 6, 2021
8,928
4,668
113
Myersville, MD
windyridgefarm.us
The pump was 173. Delivered. Which was 330 less than eBay
But 127 is really low. At this point I was happy to pay them 173. Of that 35 was shipping.
Summit said next week with luck.
I'm going to see how the loader and 3ph behave with good psi and the stock shims in the loader relief valve. I'm expecting it to be about 1900.
The new pump should be capable of pressure in the neighborhood of 3000 PSI. The actual pump outlet pressure will be limited by the Kubota relief valve setting in the hydraulic outlet block. You can and should measure that pressure at the outlet port on the block.

The relief in the loader valve can only reduce that main relief setting - it cannot increase it. I am not positive but I think the LV relief pressure adjustment is done by turning an adjusting screw on the cartridge not shimming. It is factory preset at 2000 PSI.

Dan
 

Titan17

Member

Equipment
L3901 TLB, Caroni RFM, Scag Wildcat ZTR, Piranha TB,York RE 96", MTL HD 48" grap
Jan 13, 2019
92
6
8
Uncasville, CT
The new pump should be capable of pressure in the neighborhood of 3000 PSI. The actual pump outlet pressure will be limited by the Kubota relief valve setting in the hydraulic outlet block. You can and should measure that pressure at the outlet port on the block.

The relief in the loader valve can only reduce that main relief setting - it cannot increase it. I am not positive but I think the LV relief pressure adjustment is done by turning an adjusting screw on the cartridge not shimming. It is factory preset at 2000 PSI.

Dan
 

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Titan17

Member

Equipment
L3901 TLB, Caroni RFM, Scag Wildcat ZTR, Piranha TB,York RE 96", MTL HD 48" grap
Jan 13, 2019
92
6
8
Uncasville, CT
I'm back in business!! I can lift again.
Dan as I read thru many of your replies, your "not positive" statements are pretty darn spot on. Everything you say makes sense.
I did exactly as you said and had my guage on block at start-up. Took few minutes to prime, pump was packed with synthetic grease. Once primed and completely bled - the psi is 2000 at block and about 1600 at lv when fully warmed up.
I'm good with 1600. Yes appears adjustable at lv relief valve.
I'm still waiting for loader valve from summit.
I still have to lightly tap the joy stick sometimes for 3ph but it responds guickly.
I think another fluid change is in order also.
 

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