FEL Quick Dump

[J_J]

There is something not right here, or is it only Mahindra owners with Cross valves having trouble with regen.

I talked with the reps at Cross, and the valve with regen should work like any other valve with regen.

If you add the rod side fluid to the pump flow, the speed of operation of the cyl will increase. Scientific fact.

The regen simply blocks the flow to tank and adds the rod end flow to the base end flow, and that is an increase in speed of the cyl.

If you are sure you have regen, you will see an increase in curl down or dump speed. That is a fact.

Have any of you verified that your bucket spool is regen with the parts on the end of the spool?

Take the cans off the bottom of the curl spool and look for regen parts.

How about some pictures of the end of the curl spool so everyone can see.

 

[arrow]

There is something not right here, or is it only Mahindra owners with Cross valves having trouble with regen.

I talked with the reps at Cross, and the valve with regen should work like any other valve with regen.

If you add the rod side fluid to the pump flow, the speed of operation of the cyl will increase. Scientific fact.

The regen simply blocks the flow to tank and adds the rod end flow to the base end flow, and that is an increase in speed of the cyl.

If you are sure you have regen, you will see an increase in curl down or dump speed. That is a fact.

Have any of you verified that your bucket spool is regen with the parts on the end of the spool?

Take the cans off the bottom of the curl spool and look for regen parts.

How about some pictures of the end of the curl spool so everyone can see.

It does speed up JJ. Only problem it speeds up just a little bit. Would pump/cylinder size ratios effect cycle times with the bigger the cylinder vs. standard pump capacities creating slowness even in regen?

 

[mike69440]

It does speed up JJ. Only problem it speeds up just a little bit. Would pump/cylinder size ratios effect cycle times with the bigger the cylinder vs. standard pump capacities creating slowness even in regen?

The Max 28 has neither particularly large cylinders nor a large capacity oil pump. The lift cylinders are decently sized, while the curl cylinders are smallish in diameter. The pint pivot point spacing give the bucket a fair amount of leverage and the curl cylinders are long stroke.
Fortunately regen on my loader works as the label and IOM states. Dump cycle goes from sort of slow to barely acceptable fast during regen.
What gets me is the relief valve must be set at 60% rated pressure. I’ve got thousands of hours on equipment, large and small, so I think I’m a good judge that the loader performance is no where near spec. I ought to do a video to show it will not crane a 750 lb. snowplow lifting near the pins. 1,402 lbs, humbug!
The relief valve has never been adjusted, as it is covered in black factory paint. Should be an easy fix, just that the dealer that installed the loader did not bother to check.
Does anyone know what the relief pressure on the pumps should be and what the loader relief should be set?

 

[J_J]

Your MAX only has 4.6 GPM pump flow.

I found this digging through the Mahindra PDF's

NOTE: Regen position will speed up dump operation in most applications. However, operator may not see significant speed increase at high RPM due to some oil being forced over relief. Use of regen position will eliminate bucket cylinder cavitation.

It make sense in part because if the volume of fluid going to the base end is reduced by dumping fluid over the relief valve, cyl speed will not be as it should.

However, if the fluid is passing over the relief, that means that you are at full pressure and max power. Regen is supposed to have less power, but more speed. Go figure.

Mahindra high point is reduced cavitation by using regen.

Mahindra's is the only manufacturer that mentions anything about dumping fluid over the relief valve in regen.

I also found this relief pressure.

Relief Setting: 2200 PSI

Yahoo! - 301 Moved Permanently

 

[arrow]

Yahoo! - 301 Moved Permanently

I find it telling they did not publish the time in seconds for loader function leaving those areas blank.

 

[J_J]

That link was good early today.

I believe they did post the loader times.

I also remember seeing some Mahindras with Nimco loader valves, and they may not be having the regen slow problem.

Sometimes we don't get the full story from the operators, and it leads to false conclusions.

 

[J_J]

I find it telling they did not publish the time in seconds for loader function leaving those areas blank.

http://mahindracanada.ca/sites/default/files/tractor/pdf/MAH5416 pgs 012114.pdf

Raise Boom (seconds) 3.9 3.9
Lower Boom (seconds) 2.4 2.4
Dump Attachment (seconds) 2.6 2.6
Retract Attachment (seconds) 2.6 2.6

 

[oldpilgrim]

Those times are about right for mine in full dump....... regen position.

 

[arrow]

http://mahindracanada.ca/sites/default/files/tractor/pdf/MAH5416 pgs 012114.pdf

Raise Boom (seconds) 3.9 3.9
Lower Boom (seconds) 2.4 2.4
Dump Attachment (seconds) 2.6 2.6
Retract Attachment (seconds) 2.6 2.6

"Dump attachment" I assume means a bucket? I'm wondering how they are measuring this as full lock to full dump takes twice as long and more. Your first link to the 28 series seemed to be missing loader times as they appeared blank. The 16 series link does show the times but for the life of me, I don't know how they are getting these numbers for the bucket travel. Mine is not coming anywhere close to this advertised bucket dump time unless they are measuring when the first bit of load in the bucket begins to unload itself or they are taking times from a "mid point".

 

[J_J]

You can compute the speed of a cyl.


However, the bucket mechanical pin mount will determine the bucket lip speed.

The bucket will tip faster if the mounting pin is closer to the pivot pin.

2 in bore
1 in shaft
22 stroke
10 GPM

Extension speed = 1.78 sec

Retraction speed =1.34 sec

3 in bore
1.5 in shaft

Extension speed = 4.07 sec

Retraction speed = 3.01 sec

It does not matter which valve provides this flow.

If the pump is running at half speed, expect longer cyl extension times longer..