What about a quench??

[The Tuul Crib 7,336]

So I'm thinking about this part on my

Sunstrand . This parking brake pawl 

Im about to repair by welding it up. 
rather than to put it back together after welding it why can't it be quenched to harden the steel to prevent the damage again. Any thoughts on this issue ?

[953 nut 55,065]

I would be afraid it may become brittle. Hope there may be a metallurgist out the who will chime in. 

[WVHillbilly520H 10,373]

Oil quenching? It should toughen it up some... But CRS will never harden unless it's case hardening with Kasenit... https://en.wikipedia.org/wiki/Case-hardening

Edited January 30, 2020 by WVHillbilly520H

[The Tuul Crib 7,336]

17 minutes ago, WVHillbilly520H said:

Oil quenching? It should toughen it up some... But CRS will never harden unless it's case hardening with Kasenit... https://en.wikipedia.org/wiki/Case-hardening

This is helpful info. Was thinking how to 

make this part tougher against wear.

[8ntruck 6,991]

Yup.  Case heartening will make the part more resistant.

 

There in not enough carbon in mild steel for heat treatment to make any big difference in the hardness of the part.

 

Kasenit will supply extra carbon that will be absorbed in the surface of a mild steel part when it is heated to the proper temperature.  After the carbon is absorbed, quenching the part will produce a hard skin.

[oliver2-44 9,679]

It might be better to let the brake pawl be the "wear" part and there by save risking damage to the transmission gear that is doing the grinding!

[bc.gold 3,403]

Have you put a file to one of the sharp edges on the parking brake pawl to check for hardness.

 

[daveoman1966 3,745]

3 hours ago, The Tool Crib said:

This is helpful info. Was thinking how to 

make this part tougher against wear.

There is no reason for the parking pawl to wear, if it is properly engaged ONLY when at FULL STOP.  They wear down because of 'Panic Stops".  Question:  would you put your car/truck into PARK while moving...??  The PARK PAWL will hold the tractor from drifting when stopped on an incline and should NEVER be engaged while moving.   Here is an example of what happens when it gradually grinds down:  When soft internal surfaces like these get scored, oil pressure is lost thru those score marks... precipitating motion AND hydraulic power loss.       

[bc.gold 3,403]

Wear specs Sundstrand 90-1113 some of which maybe of use to you.

 

Is that thrust plate integral to the base.

 

I think you're going to find out there's another pump inside that hydro, and that will be your charge / implement pump. Middle image - charge pump

 

Common problem with the charge pump is that the drive pin often shears off cutting off the oil supply to the pump side of the hydro.

 

 

Edited January 30, 2020 by bcgold

[daveoman1966 3,745]

There is, in fact, a Charge Pump (Gerotor set) behind the charge pump housing shown above.  It, too, MAY be scored...as well as the Thrust Washer.  A few other pics are offered here as well.  

[The Tuul Crib 7,336]

7 hours ago, daveoman1966 said:

There is no reason for the parking pawl to wear, if it is properly engaged ONLY when at FULL STOP.  They wear down because of 'Panic Stops".  Question:  would you put your car/truck into PARK while moving...??  The PARK PAWL will hold the tractor from drifting when stopped on an incline and should NEVER be engaged while moving.   Here is an example of what happens when it gradually grinds down:  When soft internal surfaces like these get scored, oil pressure is lost thru those score marks... precipitating motion AND hydraulic power loss.       

What is the best method of resurfacing

these piston slippers?

[bc.gold 3,403]

Have you checked the socket end play, measured the slipper and piston body end to end to see it they'll be within spec once resurfaced.

 

IMO the metals that ground up the slipper surfaces the finer particles circulating in the oil would have worked their way into the socket causing excessive wear.

 

Those pump and motor elements were also used on the Cub Cadet and those parts were a direct fit onto my inline Sundstrand. used on the Allis Chalmers 720

 

Edited January 30, 2020 by bcgold

[Mudrig150 298]

What about a Deere pump from a 317? They have an incredibly similar setup, but I do believe the filter is before the pump, so maybe it'd work, even if it's just for parts? I'm mentioning 317s because theyre the easiest to deal with part out wise.

[daveoman1966 3,745]

This overhaul procedure applies to Sundstrand HydroGear models 90-2046 and 90-2062 as well as earlier Sundstrand models 3100077 (1965 thru 1967). 

FIRST....It is CRITICAL to keep these parts CLEAN when making re-assembly.  Keep a small tub of kerosene to rinse EVERY PART while working on, AND as a rinse just before assembly.   Also CRITICAL to use Start-up oil too…

 

Get 2 sheets of 220  400 and 1000 grit sandpaper and tape to a SMOOTH surface plate.  Using a ‘Figure 8’ motion, sand off the scratches or score marks on internal parts.  PS…put a drop or two of oil on the grit paper….it’ll last much longer.   Prepare to refinish these if scored:   Brass Piston Slippers, Base of Cylinder Block, Face of Charge Pump Housing, both sides of the 2-pc Gerotor Set. 

 

With  the 9 PISTONS (with brass slippers) in the CYLINDER BLOCK, mark ONE of them  with felt-tip and put a corresponding mark on the cylinder block at the bore THAT piston came from.  Then lift the 9 Pistons with the RETAINING RING out and set into the plastic cap of a spray paint can...or whatever you can to keep them in original order.

 

One by one, using a ‘Figure 8” pattern, progressively thru 220—400—100 grit paper, sand out all scratches and scoring.  DO NOT take off more material necessary to bring parts to a buff finish…don’t need mirror finish on any parts. 

 

As each SLIPPER is buffed smooth, use compressed air to blow thru the NEEDLE TIP of the Brass Slipper to clear it of any debris.  (I use aerosol air can…pretty handy to have.  As each slipper is finished, rinse it in kerosene and replace to retaining ring.  On to the next one….

 

If the BASE of the cylinder block is scored….probably is…use the same ‘8’ motion to sand it smooth too.  THOROUGHY flush in Kerosene.  Inspect cylinder bores for damage or nicks of any sort. 

 

CHARGE PUMP HOUSING:  Same ‘8” motion to resurface if needed.

GEROTOR SET…this is a 2-pc set and MUST be refinished together.  EXTREMELY careful to remove as little material as possible.  This Gerotor set fits PRECISELY into the cavity on the backside of the Charge Pump Housing.  Removing excessive material (making it thinner) MAY be detrimental in that now the cavity will be too deep.  It would be a good idea to sand smooth the backside of the Charge Pump Housing to make the cavity less deep in order to retain the precise fit of the Gerotor Set.  

 

THRUST WASHER:   this is HARD steel and not easy to sand.  If scratched, just flip it over.

 

 

[The Tuul Crib 7,336]

Thanx @daveoman1966

This is very helpful info. Im hoping to get to it soon.