Loader 'curl' is weak

California · Jun 7, 2004

Loader \'curl\' is weak

I needed to transport some water for some newly planted trees. No problem, I'll just deliver these three unused garbage cans in my loader. About 600 lbs, with the center of gravity beyond the bucket lip.

I had no problem lifting the weight but I discovered the bucket 'curl' slowly droops forward so I had to stop every minute, set it down, and curl it back. I thought 'curl' should be stronger than 'lift'. Pulling the curl lever under load was worse, it drooped as soon as I pulled it back from center position and higher rpm didn't help.

I assume I need to overhaul or replace the loader control. Is this a DIY project? Cost?

The loader is a 20 year old Great Bend GB-20 with two separate control levers. Its lift capacity is considerably more than the 700 lbs I have used it for so far.

Has anybody repaired a similar problem? Advice?

JerryG · Jun 7, 2004

Re: Loader \'curl\' is weak

Sounds like normal bleed by to me. The spool to housing is metal to metal, thus nothing to rebuild. There are a few o-ringsl on the valve, but they are mainly to prevent leaks. Either the tolerance stack is causing it or the spool is worn. But a large amount of bleed off is normal. /forums/images/graemlins/crazy.gif

Jim_Fisher · Jun 7, 2004

Re: Loader \'curl\' is weak

California,

( Has anybody repaired a similar problem? Advice? )

I had a similar problem on a John Deere 430 loader. Rebuilding the curl cylinders resolved the issue. You need to do a bit of diagnosis before proceeding.

Assuming that the loader boom is not weak and doesn't leak down at an unacceptable rate, change the curl circuit to the boom valve spool and the boom circuit to the curl spool.

If the problem is the valve spool, I would expect it to now move to the boom. If the problem is in the curl cylinders, it should stay with the curl.

Let us know what you find.

Jim Fisher

jmc · Jun 7, 2004

Re: Loader \'curl\' is weak

Sometimes for diagnosis, you can switch hose pairs at the control so that the lift circuit operates the curl, and the curl circuit operates the lift. If the curl is still bad, it is probably the curl cylinder(s) or curl hose restriction. If the problem moves to the lift, its the control.

SPIKER · Jun 7, 2004

Re: Loader \'curl\' is weak

A much easier way to trouble shoot it is at the cylinder where the hose attaches to it at. One hose will be attached at the lower end twards the bucket, this hose is under pressure when the curl back is used, NOW take the other hose end off. at the curl down end, (upper end of the cylinder) make sure you have a bit of weight in the bucket , if there is leakage at the cylinder then fluid will ooze out of the nipple where the hose was disconnected from, if it runs out of the hose (then the other side cylinder is the bad one.) if NO fluid oozes out then it is in the valve which is bad, and probably will have a cut o-ring or worn spool...

be sure to think it through before taking any hoses lose too... the PRESSURE PUSHES aginst the piston / rod and PUSHES the bucket back. to UNCURL it goes the toer way and fluid pushes aginst the piston top and none aginst the rod. this extends the rod and causes the bucket to curl forward into the dump postion...

Mark M... /forums/images/graemlins/smile.gif

California · Jun 8, 2004

Re: Loader \'curl\' is weak

That is great advice, to swap hoses, and also to open a connector to see what leaks under what control positions. I appreciate the input. These diagnostics should pinpoint where the problem is.

I suspect analysis will show that the curl valve is leaking internally. Assuming this is the case, is it simple to pull a detent spring or something equally easy, slide out the piston, and replace o-rings? Or do I need to remove the control and take it to a hydraulic specialist. I assume repair will cost far less than replacing the control outright?

Thanks for any and all advice!

JerryG · Jun 8, 2004

Re: Loader \'curl\' is weak

The spool is metal to metal, no-rings.

jinman · Jun 9, 2004

Re: Loader \'curl\' is weak

Control valves are made to very tight tolerances and are almost never the problem. Don't tear into it until you check your curl cylinders. If your valve isn't sticking open, the cylinder is surely your culprit. /forums/images/graemlins/smirk.gif

SPIKER · Jun 9, 2004

Re: Loader \'curl\' is weak

I have not tore into any spool valves in for ever: some DO have o-rings, some do not, some have teflon back up o-rings with speciallized o-rings that can only be repaired using an OEM kit. not many are made the same way... Same goes for the Hydraulic Cylinders, but typically they have more redily available kits for rebuilding them, I saw them at TSC this past weeek even.

I was a Hydraulic Specilest in Air Force in Hydraulic Back shop for 4 years.. Can't tell you how many Brakes, Accumeulators, Actuators and misc componets I rebuilt!
Same for making Hoses and such! more than I could count...

Anyhow good luck with the leak down prob. My loader does the same thing in both curl and lift. I suspect mine to be more of a relife valve problem, something stuck or a tear/cut in an o-ring. lots of times a small metal flake will come loose and stick in the seat once stuck it will stay there. gets imbedded into the o-ring or even will sice the o-ring a bit. after that it's all over but the rebuilding! /forums/images/graemlins/frown.gif

Mark M

JerryG · Jun 9, 2004

Re: Loader \'curl\' is weak

Spiker,
Jim and myself, have been referring to loader valves only. The loader valves on compact tractors are low end valves. I have no doubt that you have rebuilt valves that have o-rings and backers, but those are much more expensive valves than are on these compact tractors.

jinman · Jun 9, 2004

Re: Loader \'curl\' is weak

( I suspect mine to be more of a relief valve problem )

SPIKER, I can't speak for a Yanmar, but on my New Holland, when you have a load in the bucket and release the joystick, there is no relief valve in the circuit. Once you get the load lifted, it's not coming down unless you blow a cylinder, hydraulic hose, or your tractor does a nose dive.

The relief valve is only in the circuit when you are raising or lowering the loader arms or bucket. I was back-dragging with the bucket almost vertical and hit a stump. I popped a hose like it was a balloon. /forums/images/graemlins/blush.gif I thought the relief valve should have protected me until I looked at the schematic. /forums/images/graemlins/crazy.gif

polecat · Jun 22, 2004

Re: Loader \'curl\' is weak

I' gonan have to git in on this one cause i need to know more bout the hydraulics on my cut too!!so keep gon on this great thread guys!!!..keeep the info coming.....think im jist gonna replace my rams!!!anyone know of a place that has every dimension ram available!!!????and has a catalog on their site too??tsc i looked up up but didn't see much!!!maybe i missed something????

Junkman · Jun 23, 2004

Re: Loader \'curl\' is weak

Check around locally for a rebuild of rams. It will be less expensive to rebuild than to replace. Ask the local garages, because the people that do jacks usually do the rams also. Possibly a NAPA store might be able to recommend someone, because NAPA usually make up hoses and so do the rebuilds. When one doesn't have what they need, they call the other....

polecat · Jun 23, 2004

Re: Loader \'curl\' is weak

Personally my rams are junk!!!!!..nothing but problems since day one!!! first of all they are alum. and the only thing that keeps the gland in is an inside c clip..I AM REPLACING THEM!!!
MAYBE JIST 2 AT A TIME BUT THEY R GOING ..PERIOD...i found an awesome site tonite that had a great catalog.....surplus center in nebraska!!!..and they charge 1.84 on top of shipping from ups...and they r sending me a catalog too..they had about 600 different types and sizes of rams..will keep digging tho!!! /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif
and thanx for the help jster..glad yer back..where the heck did u go tho??? /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gifno pics on yer adventure!! /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/cool.gif /forums/images/graemlins/cool.gif /forums/images/graemlins/wink.gif /forums/images/graemlins/wink.gif

Jim_Fisher · Jun 23, 2004

Re: Loader \'curl\' is weak

Polecat,

Here's another source for you: Prince Direct

Jim Fisher

jrlichina · Jun 23, 2004

Re: Loader \'curl\' is weak

Surplus Center has more than what they put in the catalog. If you call them with your dimensions they should be able to match what you have. I been using them for years and always had good luck with them.

polecat · Jun 24, 2004

Re: Loader \'curl\' is weak

sorry bout stealin yer thread cali.... /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif
but i am literally runin my cut right now on 3 rams...and u think yer bucket curl is weak!!!!! /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

Thanx for the link JIM!!!went there and went thru the whole thing but they jist dont seem to have that big of a selection...
/forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif
I spent 8 hours yest...eve till bout 5am...ayup all night!!!!!!!
and surplus center was the best catalog i've seen so far!!!!

I am lookin for an online catalog with pics and prices!!!!!
HAS ANYONE GOT ANY OTHER GOOD PLACES TO GO TO ?????????? /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif
.............................HELP!!!!!!!!!!!!.................................
PLEASE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif

Todd

BGL990 · Jun 24, 2004

Re: Loader \'curl\' is weak

Ever heard of Princess Auto? Lots of goodies, will even custom build cylinders for you. The only possible problem is that I don't know if they ship outside Canada. For that matter, I don't even know if they ship at all or if you have to go to one of their stores. If nothing else, their .pdf catalog has lots of pictures to look at ... /forums/images/graemlins/laugh.gif

www.princessauto.com

ps. All the catalog prices are in Canadian dollars.