Hydraulic pump weak

[lakespirit]

Yes, another issue to resolve. I use and abuse this poor little tractor (KAMA TS 254C). My hydraulics are sloooowww. I've cleaned the reservoir, flushed the system, replaced the filter, and both valve adjustments on the front and side of the tank are wide open. I've fiddled with many ope-shut combos I can think of. I must rev the engine to 2000rpm to get the loader up and it's still slower than molasses.

Are they rebuildable? How about for the back-yard wrench like me?

 

[Soundguy]

Any time you dink with hyds it's always good to plumb in a gauge to see what pressure is being developed... a weak pump can be as simple as a stuck relief valve!

soundguy

 

[Eagleview]

If you know for a fact it's worn out and you just want to give it a little pep , try changing the hydraulic oil to 15w40 engine oil . It wont rebuild it but it does make a difference .

 

[greg_g]

Are they rebuildable? How about for the back-yard wrench like me?

Yes, but that may be a bit premature. What about your rear lift? Is it any slower than usual? I ask - because I'm pretty sure it's run by the same pump. As for rebuilding, that's pretty much limited to seal replacement. If there's damage to the housing or the rollers, that's pretty much replacement times. With a seal issue though, I'd expect to see signs of leakage - either internal (into the engine oil) or external - and an otherwise unexplained loss of fluid from the hydraulic sump.

If your TS254C loader is plumbed anything like the one on my TS354C, there are half a dozen QD connectors in the loop. They can/will/do clog up, as can the valves in the joystick controller. IF that's the case, putting in thicker hydraulic fluid may only worsen the situtation.

If this issue arose on my 354 - assuming no obvious fluid loss - first thing I'd do is clean out all the QDs. They can be unscrewed from the hose ends, and washed out individually. If that works, I'd count myself lucky - because it's a bit more complicated to clean the controller. After I knew my flow through those components was unrestricted - AND if the loader was still slow - then I'd try the thicker fluid experiment; AW46 or AW68 to start.

//greg//

 

[DwayneB]

Are they rebuildable? How about for the back-yard wrench like me?

I've rebuilt one. I blew the seals while under warranty. Chip sent me a new pump and I ordered a seal kit for 25 bucks and rebuilt the spare. I put the rebuilt one back on and put the new one on the shelf for a spare.

The kits are cheap and a good spare part to have around even if you don't need it.

I hate those chinese quick connects. I've gradually gotten rid of them.

 

[arveeotto]

Lakespirit

Is your steering and 3ph also slow? If it is only the loader that is slow, remove pressure relief valve on loader valves and clean. I have had this happen twice where a paint chip held PRV partially open causing extremely slow loader operation.

Rick

 

[3RRL]

What the guys are saying about checking the QD's and pressure relief valves in the system is very important. Not only that, but those Chinese valves are not the greatest and they leak past spools from one to another and cause all kinds of problems ... specifically poor performance. I'd check the valves and QD's and also look for any other restrictions.

If you plumb a pressure gauge into the system, you can set all the pressure reliefs to the proper amount. On my wife's 284 Jinma, the rear remote valve is faulty and so is the pressure relief on it. I plumbed in a pressure gauge and set the main system at 2321psi and all the valves at 2200psi (my choice). However, that one rear remote valve was malfunctioning. When operated it fluctuated on the gauge between 800psi and 1200psi ... I couldn't adjust the pressure relief on it either. I tried making several adjustments with no difference. It's just a crummy valve and I'm taking it out of the system.

Having said all that, if everything checks out fine and you still want better pump performance, you could buy a larger pump with more flow. You can get them from Tommy or Ronald or Chip. I did that for my Kama 554 and got tremendous results going that way. You may want to check which pump you have and go one or two sizes up. Just be sure the spline is correct for your Jinma.
Here's a thread to that.
CBN-E320 Pump for Kama 554

 

[lakespirit]

Do you know how much pumps cost?

 

[Eagleview]

I had thought of buying a Chinese tractor for smaller jobs but if thier filtration system is so bad that they can have material big enough floating around to block fittings i'll pass . Do they use chicken wire for filters ?

 

[greg_g]

I had thought of buying a Chinese tractor for smaller jobs but if thier filtration system is so bad that they can have material big enough floating around to block fittings i'll pass . Do they use chicken wire for filters ?

No filtration per se, typically suction side screens inside the sump - some of which are user replaceable. I use 80x80 brass mesh on mine. A few (not including Jeff's) have external elements, but are typically just 125-150 micron screens inside a spin-on housing.

I don't know if this is any better or worse than "other than Chinese" tractors. But I do know that a lot of the Chinese QDs are problematic. especially the cone type. It doesn't take much grit to constitute blockage. And if you're not careful when opening/closing QDs, the grit doesn't even have to come from the hydraulic fluid.

//greg//

 

[RonMar]

Are you using a stock/chinese spec hydro filter on it? Are you sure it is a mesh strainer cartridge? If it is the same number as the original you replaced, do you still have the original to cut apart and examine the media?

If it was a QD restricting flow, then the pump would be getting hot from the restriction. If you suspect it is a QD, the chinese QD's are real easy to disassemble and remove the checkball mechanism. It only takes a set of snap ring pliars. The ring, spring plate, spring and ball are easilly removed. This of course has to be done with both QD halfs of any two that will ever be put together. This is easy to do for the loader QD's as they are only ever mated to their counterparts or themselvs on loader/tractor . You will loose a little fluid if you ever have to take the loader on/off, but only a little as you dis-reconnect the fittings. And if a QD is ever inadvertently disconected, you won't deadhead the pump.

Have you actually measured the pump output volume? If you have a half remote on the back, and another Quick Connect(mine came with a set in the spare parts). This is probably the easiest way. Or you can remove a loader line and run it into a bucket and send fluid to the bucket with the loader control valve. Time how long it takes to fill a gallon bucket, then dump the fluid in the bucket back into the resovoir. You will need to know two other pieces of info to make use of this timed gallon delivery.
1. Volume per revolution of your particular pump. This is probably expressed as Millileters per revolution ML/R(3785.412 ML per gallon)
2. Pump drive gear ratio if any(there are 4 gears involved on a Y385 engine, but I don't know the ratios), so you know how many RPM the pump is turning.

 

[greg_g]

Disregard what I said about rising engine oil level Jeff, I forgot yours is a PTO pump. But I'm still curious if this is just a loader problem - or if your rear lift is affected too

//greg//

 

[lakespirit]

I am not the technical sort as many of you are. I don't have a way to measure pressure or flow. My oil never gets to hot. The loader and the 3Pt arms are slow.

I changed out the oil and put in 15w/40 which seems to improve speed initially, but I still don't have the lifting capacity I once had. I still cannot get the bucket to lift the front tires aven an inch.

My filter is the small cylindrical screen-mesh in a housing on the outside of the reservoir. I could not find any blockages and had all the QD's off, as well as all fittings at the control valve. Everything seems to flow quite well, as the huge flood of oil proved.

 

[greg_g]

Putting engine oil in the hydraulic system is an expensive experiment. I really hope you don't intend to keep it in there permanently. It's not formulated for the kind of heat and pressure generated in hydraulic applications. besides, a 5 gallon container of AW68 hydraulic fluid is typically less expensive than 5 gallons of 15W40 - and you wouldn't likely have had to drain it out when finished with the experiment.

Anyway, done is done. That money's gone. And I'd hate to see you spend more on a pump you may not need either. But before we can go there, I still have no idea if this issue is limited to your loader - or if your rear lift is affected as well. This is important - because the same pump provides fluid to both.

//greg//

 

[Soundguy]

Lake spirit.. invest in a 0-3000 psi pressure gauge....It's a very usefull tool when playing the guessing game about hyds. Also.. please answer some of the questions that are being posed to you.. it helps us narrow down what parts of the circuit are effected.

soundguy

 

[DwayneB]

I am not the technical sort as many of you are.

If your pump has ever dead headed I would say there is a 100% chance the seals in the hydraulic pump blew. Or if one of your relief valves is set a little too high it could of damaged the pump seals. These little pumps won't stand much over 2000 lbs.

Like soundguy said, a pressure gauge will tell you quick about your pump or restrictions.

For what you spent on oil you could of rebuilt the pump. They are very simple. 1 seal, 2 o-rings, and 2 W shaped seals. 4 bolts hold the 3 main pieces together. If the shaft and gears and bushings are ok a new seal kit will make it good as new.

BTW, almost all of todays new zero turn mowers use 20W50 motor oil for hydraulic fluid.

 

[greg_g]

If your pump has ever dead headed I would say there is a 100% chance the seals in the hydraulic pump blew.

Dwayne - as I mentioned before, the TS254C loader and rear lift are supplied by an external PTO pump. It's it plain sight behind the tractor. If we were looking at a seal problem, I believe Jeff would have mentioned hydraulic fluid all over the back end of his tractor by now.

My wife once owned an Austin Metro with an automatic transmission that operated on 10W30 supplied by the engine oil pan. Never once crossed my mind however, to compare it to a Chinese tractor.

//greg//

 

[DwayneB]

I believe Jeff would have mentioned hydraulic fluid all over the back end of his tractor by now.
/

Mine didn't, some fluid was bypassing the seal into the tranny and the rest was bypassing an internal seal that was blown to pieces.

I'll bet ya it ends up being the pump, lol.

 

[greg_g]

Mine didn't, some fluid was bypassing the seal into the tranny and the rest was bypassing an internal seal that was blown to pieces. I'll bet ya it ends up being the pump, lol.

Your money. But it's a fools bet until we learn what's happening with the rear lift. For the record, there's is no direct passage between the PTO pump and " the tranny ". To be fair, you probably meant rear differential - which would be through PTO oil seal #14 - not one of the actual pump seals (#1, 19, 20). They'd more likely pee hydraulic fluid outside the tractor.

//greg//

 

[DwayneB]

To be fair, you probably meant rear differential .

Yes you are right, it was the differential I was just calling the whole mess the tranny.

I guess I am a fool then cause I'd take the bet.