Backhoe slow bucket response

[magyarbacsi]

I just recently did my 50 hr service on 5525 with Bradco BH. I purchased Napa UT oil to replace factory. I noticed that the Napa UT seemed little thicker than the factory fluid. Is the factory use thinner as a break in oil and Napa UT is ok? Sometime later, while using the BH in 70-75 degree weather the bucket opened very slow. Everything else, boom extent/close, swing and bucket closing was normal. It just took longer for the bucket to open, but would scoop normally and closed fine. I used all Mahindra filters. The only thing I did not get to is a strainer at the bottom of the tranny. It looked as if I had to remove some of the machinery to get to the strainer so I did not open that up. You'd think even just gravity would allow the 16" bucket jaw to just drop freely, but it acted like something,i.e. back pressure, was holding it back. No noise, squelling or such and it worked faster at times, but for most part, while digging out a small stump, it was slow. I did not change any of the control valves, the ones that govern swing and such.

 

[bindian]

I just recently did my 50 hr service on 5525 with Bradco BH. I purchased Napa UT oil to replace factory. I noticed that the Napa UT seemed little thicker than the factory fluid. Is the factory use thinner as a break in oil and Napa UT is ok? Sometime later, while using the BH in 70-75 degree weather the bucket opened very slow. Everything else, boom extent/close, swing and bucket closing was normal. It just took longer for the bucket to open, but would scoop normally and closed fine. I used all Mahindra filters. The only thing I did not get to is a strainer at the bottom of the tranny. It looked as if I had to remove some of the machinery to get to the strainer so I did not open that up. You'd think even just gravity would allow the 16" bucket jaw to just drop freely, but it acted like something,i.e. back pressure, was holding it back. No noise, squelling or such and it worked faster at times, but for most part, while digging out a small stump, it was slow. I did not change any of the control valves, the ones that govern swing and such.

Magyarbacsi,
When you say you changed the oil, do you mean engine oil? Anyway, I don't think Napa UT is on the Mahindra recommended fluid lists and could void your warranty. I would think a thicker hydraulic fluid (oil) could cause slower responses. I use Shell Rotella T in the engine and Shell Donax in the transmission and hydraulics.

If your BH is powered through the remote, remove the line quick disconnects and reinstall them. I have had slow movement before when a disconnect "pops" off enough to cause slowness, but not far enough to pop completely off the remote fitting.
hugs, Brandi

 

[magyarbacsi]

Hi Brandi, yes I did change the engine oil too, but my concern was about the change of tranny oil. The booklet had recommendations re tractor fluids, but did not prohibit Napa UT, but I will read it again to make sure.I only have <2 hrs on the Napa UT. Besides, I had the tractor past the warranty years, its just not being used often enough hence the low hours. I have an older Messey 165 that is used regularly for field work. The Mahindra is used for excavating, stump removal and such which I dont need to do too ften, or choose not to. This is at our 9 acer vacation/2nd home and land that some day will be our primary when I retire. (I'm constantly reminded to keep working, millions on welfare depend on us).

I dont have the quick disconnects. As I menioned, the UT fluid that came in the tractor,the factory, was thinner than the Napa and all the other implements that are run off the same pump and fluid, i.e. bucket, BH boom work as before. Just the lower clamp of the bucket when I open it up is S-L-O-W, but clamps shut normal. I was wondering if the factory fluids is thinner as used for break-in and then swithc to a heavier grade or is the one I putin too heavy, but then would that not be simptomatic throughout the entire hydraulic system?

 

[Texan4Life]

If it was the fluid I would expect it to effect the whole system.

perhaps the spool that controls the effected cylinder or the cylinder is leaking internally? ie. allowing fluid to bypass an internal seal resulting is lower flow/pressure?

my $.02

 

[bindian]

I'm thinking it is the fluid. Is the fluid you installed, in the book as a recommended fluid? There are reasons (only Mahindra can answer) why Mahindra recommends some fluids over others. I'm thinking the cylinder that is slow has a smaller port and the thicker fluid is not moving through as fast as it did before the fluid change. Other than that, you could have got some debris blocking the port to that slow cylinder.
hugs, Brandi

 

[valleyfox170]

i just recently purchase a Mahindra 509 made by bradco for my 8560 my bucket does the same thing really slow opening but everything else works great I bet we have the same problem

 

[arrow]

My 3016's bucket response is a turtle right from the factory.

 

[bindian]

Texan4life,
Try bleeding the BH curl and dump lines. Might be air.

Valleyfox170,
You may think your Bradco 509 BH was made for your 8560,but that is not the case. The 509 and 511(same parts but longer stick) BH's have been around for at least 7 years, when I bought my 6520. The 6520 is the smaller, older brother to your 8560.
hugs, brandi

 

[burzynsr]

I use Tractor Supply "Premium" fluid in my 4025. The Tractor supply fluid has a long list of approved uses in a multitude of equiptment listed on the container. If I am correct it is a 20 weight oil. Bindian is right about the fluid. Napa UT is not on my list in the manual either. The Shell Donax is what you need, a little more expensive but you wont be changing it again until 1000 hours if memory serves me correct. Good luck.

 

[burzynsr]

If it is not on the reccomended list don't use it.

 

[Shift4200]

My 3016's bucket response is a turtle right from the factory.

+1 to this for my Max25.....

-J

 

[arrow]

+1 to this for my Max25.....

-J

Shift....I found the speed up for the bucket dump! No...don't get excited. It goes from dead slow to just slow. I watched a Cat 960G pay loader the other day dump its bucket. Ours is as fast as that.

 

[bindian]

When dumping my 511 BH bucket, I extend the dipperstick at the same time. Just timing the bucket.... ....will "seem" slow.
hugs, Brandi

 

[Shift4200]

Shift....I found the speed up for the bucket dump! No...don't get excited. It goes from dead slow to just slow. I watched a Cat 960G pay loader the other day dump its bucket. Ours is as fast as that.

Ugh, not the news i was hoping for. Sadly I had a similar experience when playing with a "friend of a friend's" Massey last weekend. It's a ~30hp tractor and in all honesty, i think ours dumps a little faster. The only thing I preferred on the Massy is the loader control handle being progressive in speed vs our "progress to regress to progress" type setup.

Take that loosely, I really only had 5 min or so to mess with it. This was the first time I met the guy, and within minutes of our first handshake i was asking to try out his loader.....

-J

 

[oldnslo]

Slow speed on a single function is not an oil problem. Sounds like either a restriction in the line from the factory or the cylinder and geometry is such that full speed is still slow. Has anyone timed the cylinder travel speed in inches per second and then back figured what the flow rate of oil is in GPM to see if it matches the pump out put flow?

formula is: Q = VA

Q= = flow rate in GPM
V = cylinder velocity in IPS (inches per second)
A = cylinder area in square inches

example: 2 1/2 bore cylinder extends at a rate of 4 IPS

2 1/2 bore = 4.9 square inch area X 4 IPS = 19.6 cubic inches per second of oil flow

19.6 divided by 3.85 = 5.09 GPM

3.85 constant is derived from 231 cubic inches per gallon divided by 60 second in a minute

 

[arrow]

Slow speed on a single function is not an oil problem. Sounds like either a restriction in the line from the factory or the cylinder and geometry is such that full speed is still slow. Has anyone timed the cylinder travel speed in inches per second and then back figured what the flow rate of oil is in GPM to see if it matches the pump out put flow?

formula is: Q = VA

Q= = flow rate in GPM
V = cylinder velocity in IPS (inches per second)
A = cylinder area in square inches

example: 2 1/2 bore cylinder extends at a rate of 4 IPS

2 1/2 bore = 4.9 square inch area X 4 IPS = 19.6 cubic inches per second of oil flow

19.6 divided by 3.85 = 5.09 GPM

3.85 constant is derived from 231 cubic inches per gallon divided by 60 second in a minute

I'm willing to bet ...no. Basically, I for one have little idea about what you are talking about. I acquire the gpm which is 7.8 @ 2600 rpm's. The bore is 1" and extends to 4" in one second so its .78x4" = 4 cu ins oil flow. Now if I read you correctly that 3.85 is a "constant" and divide that into 3.12, I get a little bit over ".8". Something seems not right here if pump flow is 7.8? What'd I do wrong? In the manual, lock to lock dump speed is 2.6 seconds. Mine is closer to 7 seconds.

 

[oldnslo]

Arrow,
your math is correct.

If you are talking about dumping a back hoe bucket you would have to use the differential area of the cylinder for figuring flow since the cylinder retracts to dump. Differential area is the rod area subtracted from the cylinder bore area.

On a loader bucket typically extending dumps the bucket so you would then use the cylinder bore area and if their are two cylinders you would then have to double the area to get an accurate flow rate.

Dumb question but.. With the back hoe raised off the ground and the bucket curled fully (like lifting a scoop full of dirt) and the engine off. If you move the control valve to dump the bucket does it drop slowly?

 

[arrow]

With the back hoe raised off the ground and the bucket curled fully (like lifting a scoop full of dirt) and the engine off. If you move the control valve to dump the bucket does it drop slowly?

No back hoe but yes, it dumps rather slowly.

 

[J_J]

Are you running the engine at max?

You only have max flow at max rpm.

In order to do a cyl speed test, it has to be a goood cyl with no leaks.

Are you using regen if it has regen?

Check your fitting and make sure there are no restrictor fittings in the flow path. Restrictor fittings will limit the GPM, and hence your flow.

Have a hyd shop put a flow meter in the line and see what the flow is.

You can do a flow test yourself by removing the bucket hose and put in a 5 gal bucket. Then use the lever to put hyd fluid in the bucket.

If you can fill to the one gal mark in 6 sec, then you have a 10 GPM flow.

A good cyl will have a speed factor, but the mechanical hookup will also

play a part by the distance of the bucket pins to the cyl connecting point.

The closer the cyl connection to the pivot point, the faster the dump.

 

[arrow]

Are you running the engine at max?

You only have max flow at max rpm.

In order to do a cyl speed test, it has to be a goood cyl with no leaks.

Are you using regen if it has regen?

Check your fitting and make sure there are no restrictor fittings in the flow path. Restrictor fittings will limit the GPM, and hence your flow.

Have a hyd shop put a flow meter in the line and see what the flow is.

You can do a flow test yourself by removing the bucket hose and put in a 5 gal bucket. Then use the lever to put hyd fluid in the bucket.

If you can fill to the one gal mark in 6 sec, then you have a 10 GPM flow.

A good cyl will have a speed factor, but the mechanical hookup will also

play a part by the distance of the bucket pins to the cyl connecting point.

The closer the cyl connection to the pivot point, the faster the dump.

I did measure at the 2600 rpm rev point calculated for the pump of 7.8 gpm. I think it is slow because the desire of curl capacity from the factory out shone speed. The hoses look inordinately small (narrow) from others I've seen. I do not see how Mahindra advertises a 2.6 second dump time as it is no where near that.