Slow Initial Steering Response (Hydro)

[Texasmark]

I was running through my hydraulic schematic and found that my steering pump sucks out of the sump after the main hydraulic filter and services only the steering cylinder. I also noted that the return line goes through a hyd. fluid radiator up front. At 4 gpm with main flow of 11 gpm from the main hyd. pump (15 gpm total), both pulling directly down line of the single hyd filter, none of the remainder of the geared, shuttle shifting tranny, nor 3 pt, nor electric/hydraulic clutch pack, nor FEL feed discharge back through the cooler whose outlet is back to the main sump.

None of the other systems are having an initial startup sluggish problem like the steering (just recently with cool mornings), of taking awhile to build up pressure. Since both run off the same filter and I changed filter and fluid last year (OEM filter PN and Premium, popular brand TDH fluid) with not that many hours since, always running the tractor up to temp if cranked, I don't see fluid problems as the culprit. I don't suspect a clogged main hyd filter to be the problem. The schematic doesn't show a separate screen anywhere in the system.

Question here mainly is: Have any of you ever had a hydraulic cooler clog on your tractor and if so, did you do it to yourself, or have an idea as to why?

The idea that I may have a line leaking/sucking air on the suction side of the pump on my bought new, 2007, 1800 hour tractor, certainly could be the culprit.

Anybody else have a similar problem? Tomorrow I plan to crawl up under it and have a look.

 

[ptsg]

The Tank line coming from the steering unit, that will then feed the radiator, will also feed the PTO valve. Not sure if would affect the steering though.

If you follow the suction line all the way to the transmission case, it should also have a screen or strainer as they call in the service manuals. It may need to take the actual suction hose off or it may have an access plate on the opposite side of the transmission.

With 1800 hours, it's probably due to get some cleaning.

 

[Tx Jim]

Mark
I doubt oil cooler is the problem with steering. Have you lubricated pivot points on frt axle regularly? If so my guess will be a hyd relief valve isn't seating correctly or steering control valve is leaking internally. Can Branson parts schematics be accessed online??
Jim

 

[oldnslo]

Mark
Is the steering wheel hard to turn or are the front wheels just slow to respond when cold?

Like Jim I doubt this has anything to do with the oil cooler

Are there two separate pumps mounted in two different locations or is this a piggyback back double pump system?

 

[zzvyb6]

Sounds like your tractor has "Morning Sickness" as we say in the trade. low pressure or leaking steering valve. See if it's slow in all steering angle input positions.

 

[XSKIER]

A couple of life experiences that may apply here in reference to your problem.
First, on the power steering system of a boat. This design is a pump with resivour mounted, assist ram mounted shuttle valve, oil to water cooler on the return. The problem was that after 10 minutes of run time the oil would make a foamy eruption out of the resivour, and then no power assist. The oil cooler was allowed water to freeze in it, thus restricting the return oil flow.
Second, on two of my tractors similar in design to what you describe. The first tractor old as dirt with no hour meter, the second a "new 40 hr demo" machine with 3 years of lot rot. At the end of the hyfraulic suction line there is a rubber T fitting that feeds both pumps that would develop an air leak. It was not noticeable above 50 degrees, both tractors live in a 60 degree shop, but a couple hours parked outside and the hydraulic system would be sluggish and studder. The old tractor was fixed with a new rubber T, the "new" one now has 320 hours and no amount of new Ts, clamps, extreme high oil level (so that the pump has to "suck" less) and o-rings can fix it. The dealer says that it is normal operation, and it is way down my list of priorities to make right. I'm lucky enough to have an oil leak to point me in the right direction when the time comes.

 

[Texasmark]

The schematic shows a rectangular box with the pumps side by side, parallel feed from one spin on hydraulic filter as mentioned, on the input and (obviously) separate systems on the output. Very possible, since both are shown in the rectangle that it is a double pump setup....will investigate that.

No idea as to the physical plumbing. Will have to crawl under/around it to determine what I have. I will surely be looking at any rubber connections and bring my wrenches with me to check metal fittings.

I haven't pulled up a parts diagram but will and I have access to online Branson parts diagrams/lists. In there I will be looking for a filter screen that may not be included in the plumbing schematic among other things.

I have a liquid filled 5k psi gauge that I use with my Ford hydraulic systems but I don't have the Branson adapter mentioned in my owner's or service manuals which has a variable flow, pressure build up capability adapter. Will have to cobble up something to do that or find another way...and yes I am working with 2-3k psig.

Good responses here for things for me to check and I sincerely appreciate all of you taking the time to help me with this. Will report results when I finish looking. May be a week or so.

 

[Tx Jim]

Mark
I located a hyd strainer(key 18) for a 6530 in parts catalog
Jim

 

[Texasmark]

Mark
I located a hyd strainer(key 18) for a 6530 in parts catalog
Jim

Why thank you sir for the attention. Was out just now and had a good look at the pumping system. Fluid comes from the sump through a 1.5ish diameter pipe to a split, like the letter Capital F lying on it's back. As you asked, the pumps are ganged off one driven shaft and reading the manual, the steering just circulates fluid through the assembly, out through the cooler and back to the sump unless directed to a L or R position port whereby it does it's job then back to the sump.

Now that I know what is where, the "F adapter is attached to the input supply line and to the inputs of both pumps. Both had clamps on them and both clamps accepted screwdriver adjustment. After that I had leaking fluid seeping from the main pump input and noticed adapter deterioration on the steering pump input at the clamp. I don't know if it's plastic or sturdy rubber as it didn't deflect as a radiator hose would deflect when pushed with a screwdriver tip.

Now that things are evolving, it is occurring to me that had felt that my main hydraulics aren't as quick as they once were, but blew it off, and as quick as my 2400 being 9 years younger...assuming Branson designers had a lifting speed requirement for all loaders at a given RPM and sized the hydraulics accordingly....speculation but possible.

Anyway, I'm ordering the F today and after installation we'll go from there.

Thanks to you and the other guys for their inputs and your taking the time to find a filter screen for me.

 

[Texasmark]

Jim, I can't get into a parts list to find the PN of the part I need. Where did you get the breakdown/part number for the screen?
Thanks,
Mark