Branson 4720i pto slows / aeration in hydraulic fluid

[countryboy308]

HI all, new to your forums.

I have seen a good bit of information that came from this site while trying to find some information on my tractor. I have a 2007 Branson 4720i that I purchased a finish mower for. I have not used the PTO much till now. I have had the tractor about a year and been working through some issues that I have inherited from the neighbor that I bought it from. I installed the mower and after about an hour the PTO begins to slow down. I have noticed the hydraulic fluid is aerated (which I believe is a separate problem) but I have read that the hydraulic pressures where set to low from the factory and could cause premature clutch failure... that said... does anyone know what the pressure specs are supposed to be? am I to late on getting the pressures adjusted to save the clutch? I cant find a service manual for this thing, so I figured I would say hello and ask. :newhere:

 

[LouNY]

I had held off saying anything as I dont havea4720i, but here goes.
How is your pto actuated, a lever that engages it directly?
or a switch that energizes a solenoid?
If it is a wet multi disk clutch using hydraulic pressure to activate, aeration of the hydraulic fluid
could and would certainly effect the pto operation.
The aeration could be caused by many things,
a filter leaking (sucking air),
low fluid level,
a plugged hydraulic filter,
any system leak allowing air to enter the pump suction,
the wrong fluid,

good luck

 

[ericm979]

I think the 'i' in the model name indicates independent PTO. Probably electic switched hydraulic.

Oil aireation can be caused by having the level too high. In engines when the level is too high there's more oil whipped around by the crankshaft. Dunno what in a tractor gearcase might do that but there's probably something.

The electric over hydraulic PTO on my 3725 uses hydraulic pressure to push the clutch pack together. (I am getting that from reading the service manual, not taking it apart to look. I could be wrong). Your 4720I is probably the same given how Branson tends to use the same parts in many models. Oil with air in it wont' provide as much pressure. I'm thinking that the air in the hydraulic fluid could be the cause of your PTO problem.

 

[Texasmark]

Any idea if the fluid and filter has been changed? If not, way past time to change it. Get the Branson filter number off the hydraulic filter and stick that number in a Google search engine. Lot of times ebay has them. Otherwise find a Branson dealer.....Branson site can lead you to a local dealer or just mail order from one you find. Big Red's Branson dealership in the Ft. Worth, Tx. area has a big mail order parts dept. and if you can't find a filter, give them a call with your tractor id and sn.

Fluid can be bought from TSC. Use their "Premium" Trans, hyd, wet brake, hydrostat oil.....way to tell is look on the back for the J20C spec among a long list of others.

You are probably going to need somewhere around 7 or so gallons. If you don't have an owners manual, put in 5 gal and then add a half gallon at a time and check your fluid level dip stick. Keep adding till it shows full. Crank the engine and run all the hydraulics through their paces including the PTO without any load on it. Shut it down and top off at the full mark...on my 2400 the dipstick is between your legs on the floor. On the 6530 it's right over the rear axle on the left side, top of it, accessible from the rear. Full is the top hole punched in the stick.

After you change the fluid, activate and deactivate the PTO numerous times watching the PTO respond. Then put your implement drive line on energize the PTO and watch it spin. My 6530 has 6 clutch packs on the electrically operated independent PTO. Reason for 6 is to distribute the starting load. It has a function whereby you can select if you want the PTO to turn off when you lift the 3 pt. Sometimes it's good to shut it down at high drive angles like when you have a 3pt tiller and lift it all the way. On most rotary mowers (bush hogs things) you can't use that function as the deck will hit the PTO shaft if you come up too far.

Anyway, the clutch packs are designed to reconnect at the higher rpms, like for those users that don't know or forget to drop the rpms to idle and then slowly increase to PTO rpms. Unless the PO has done a lot of PTO on and off usage, I'd think that changing the fluid will be a big step to solving your problems.