D7h transmission pump clearances (power shift)

[Josiahmuk52]

Hi I'm inspecting a faulty transmission pump and I was wondering if anyone has the specs for the different clearances.

 

[chidog]

A shop manual should have that info. Maybe Nige can help.

 

[Nige]

Machine Serial Number.?

 

[John C.]

What kind of pump, gear, vane or piston?

 

[Josiahmuk52]

Machine Serial Number.?

It's 4LG00585
It's the gear type hydraulic pump on a d6h

 

[John C.]

Two gears or a gerotor style? On the gear types I usually just run my finger nail across the pressure side pumping area and the ends of the gears. On the gerotor style pump I check the side plates for any marks. If its catches my finger nail I'll declare it bad. A lot of gear style pumps will fail in the center shaft letting the gears ride against the pump cavity. You might post of photo of the parts. It's funny that low pressure stuff is usually a lot easier to spot the problems.

 

[Josiahmuk52]

These are the photos
Wish I had a better quality camera

 

[pittsburgh cat man]

That sure looks like the hydraulic pump transmission pump has 3 sections

 

[Josiahmuk52]

Yes it is

 

[pittsburgh cat man]

You need a cat reusable guideline book for Tyrone pumps

 

[Josiahmuk52]

Any advice on where I can get one from?

 

[Josiahmuk52]

Hi, does anyone know where the hydraulic testing port is

 

[chidog]

On a cat transmission pump? Its on top. On the old ones.

 

[Josiahmuk52]

On the implement gear type hydraulic pump

 

[Josiahmuk52]

There's a problem I'm having with it.. the implement cv was rebuilt because the tilt was moving on its own, anyways, upon putting it back the implements are only moving slightly and the pressure is very low..around 80psi at high idle.. now when looking at the schematic it's saying that there is supposed to be a piston pump there, but it only ever had a gear pump.. anyways we stripped the implement control valve twice, but can't find anything wrong with it.. we also checked our pump out and fitted another one, but there's also no change.

Does anyone have any advice here?

 

[Mquinista]

Hey,
I´m not an Hydraulic expert, but had my sort of problems solved.
Something does not add up in your post as a series H machine should have a piston pump for main hydraulics.
Nevertheless, with a gear type pump, pump condition can be visually ascertain, in case u can´t ID scratches and wear, and pump is considered good, the pump control is made in the valve bank.
Oposite to variable displacement pumps, the gear type are always pumping at max flow, max pressure is set by press control relief valve. Then there are some other valves in the system wich may or may not be in the system.

Be aware that the Pressure control valve may be piloted, in this case it should work like a load sense system. Then this valve is the GURU of the system, u should direct your atention to it.

Also usually there´s a max press relief valve, this one is there to avoid system overpressure when system goes above a certain max aloud press, ex when one rams a Cylinder against a load and pressure raises above this max.

Look for valve seat and springs , O rings and sphere valves.
Both the MAX PRESS relief valve and the PRESS REGULATOR valves have regulation.

Main Pump pressure is read in the valve bank. U can either read Stby Press. Operating a spool operating press, with a ram in stall, system max regulated press.

Meanwile NIGE may be able to get the system discription and regulation charts, if u provide a serial number.

 

[Josiahmuk52]

Thanks a lot..

The serial number is 4LG00585

 

[Mquinista]

This shares some light into the system.

 

[Josiahmuk52]

Thanks, come I look at it