TC35D hydraulic pump

[tractorblue]

Dealer says my hydraulic pump is out. I want to buy and replace myself but service department says that without using a hydralic pressure gage that I would likely mess up the hydrostatic portion and cause more damage. I hate spending the additional $500 for them to do. Is it not as simple as replacing the pump, filter and fluid?

 

[dfkrug]

I assume you mean the implement pump, and not the charge pump
or main piston pump which comprise the HST.

You don't need a pressure guage to replace the implement pump, and
I feel confident in that opinion despite never having wrenched on a
blue tractor.

But if it IS the charge pump or HST main pump, you don't need a
pressure guage for that either. BTDT for Kubotas and Deeres.

 

[jinman]

I agree with Dave. Your dealer is blowin' so much smoke the EPA is lookin' for him. Your hydraulic pressure is set by the relief valve and will be the same for any hydraulic pump. Your main pump has absolutely nothing to do with your HST transmission or power steering. If your dealer told you that the hydraulic relief might be wrong and that was what ruined your first pump, then he has a valid point, however you can buy a gage and install a quick connect fitting so that you can check the pressure for a WHOLE BUNCH LESS than $500. If that dealer of yours won't sell you a pump, then order one from Messicks.com or other dealer who will be happy to sell you a pump without strings attached.

 

[tractorblue]

Kinda what I thought, its the main hydraulic pump ($685) mounted on right side engine. Seems as simple as bolting in, draining fluid, install new filter, filler up with hydraulic fluid to recommended level (dipstick) and start mowing again?

 

[jinman]

Kinda what I thought, its the main hydraulic pump ($685) mounted on right side engine. Seems as simple as bolting in, draining fluid, install new filter, filler up with hydraulic fluid to recommended level (dipstick) and start mowing again?

Yes, but do you know what caused the original to fail? Checking system pressure would be advisible if the pump didn't fail due to old age or has bad seals. Those pumps can be rebuilt with new seals. The seals are around $150. If you maybe hit something and did damage to the physical pump, replacing it makes sense. If it is just leaking, then a rebuild makes the most sense. I'm pulling mine off on Saturday when my grandson comes to help so I can get it rebuilt. I'll let you know next week what a rebuild at my dealer costs me.

 

[dfkrug]

It is interesting that this came up at the same time that one of the
CK30s I bought 6 y ago now has a big implement pump leak and I am
trying to help diagnose it long distance. That design is a single pump
with a flow divider for the power steering. I suspect the NH tractors
use dual pumps for the PS and implements?

Anyway, the implement pumps can sustain damage also from dirty
fluid, or a constricted inlet pipe or screen, which can cause cavitation.

Of course, checking system pressure is always a good idea (esp when the
tractor is new). I think the TC35 is a 2500 psi machine.

 

[jinman]

Of course, checking system pressure is always a good idea (esp when the
tractor is new). I think the TC35 is a 2500 psi machine.

It's actually 2250 psi, Dave. The TC40 and 45 are 2500, but the TC35 has reduced hyd. pressure from the main pump. Also, yes, the main pump and PS pump are separate. Here's a photo of both mounted on the engine.

 

[tractorblue]

You guys seem to know your stuff; additional question,,, my PTO lever when new of course had full 100% through from off (back position) to on (forward position) Over the last several years it would only engage around 85% forward,,, and now at about 50% .... also on ocassion lately it got to where at 0% the PTO still turns...

Of course now I'm where I started this thread... pump is out

 

[dfkrug]

It's actually 2250 psi, Dave. The TC40 and 45 are 2500, but the TC35 has reduced hyd. pressure from the main pump. Also, yes, the main pump and PS pump are separate. Here's a photo of both mounted on the engine.

Interesting. My brochure specs show 9.8GPM flow for all three: TC35/40/45,
which implies the same pump. But no pressure specs are given. :-(

The photo is of your TC45, Jim?

 

[jinman]

Interesting. My brochure specs show 9.8GPM flow for all three: TC35/40/45,
which implies the same pump. But no pressure specs are given. :-(

The photo is of your TC45, Jim?

The pump is identical on all three models. If they don't list hydraulic pressure, look for the 3PH lift specs or the 16LA lift specs, you will see those numbers are less than the 40/45. The maximum pressure is set by adding or removing shims from the relief valve. There's a detailed procedure in the Repair Manual for this. I don't like to talk about it much because somebody is always willing to shim their pressure into non-spec areas and I don't want to be responsible for enabling them. I'll let somebody else do that. As far as flow, I'm guessing NH would say that the 9.8 gpm flow is at the reduced pressure for the TC35 and at 2500 for the 40/45. I would say flow was more a function of engine rpm than relief pressure, but I don't know if that is correct or not.

Yep! My pumps in the photo on my TC45D. This weekend, I'll be pulling the pump off and taking pictures of that process. The good looking kid in the pictures will be my grandson and the fat ol' coot will be me.:laughing: