Hydraulic flow restrictors

Phils · Jan 10, 2005

When I'm operating my PT at higher RPMs, using the FEL is a touchy proposition. I have to be very careful when moving the lever or the bucket will travel very swiftly (too fast).

The 580 Case I used to own would only let the bucket travel at a maximum (reasonable) speed, no matter the motor rpm.

Would installing some kind of flow restrictor help? Would I WANT a flow restrictor in that hydraulic circuit, or would some other implement's performance suffer? And how or what would be the suggestions for a restrictor if the idea has merit?

Phil

J_J · Jan 10, 2005

Surpluscenter.com has all the restrictors you need, fixed or adjustable. I would put the restrictor close by the bucket.

MossRoad · Jan 11, 2005

There is a post somwhere on TBN about using flow restrictors in a hydraulic circuit and there was some discussion as to you may need two of them... one on each side of the cylinder, for each direction, because they pass full flow in one direction and restricted flow in the other. It may be worth a search. /forums/images/graemlins/wink.gif

Phils · Jan 11, 2005

Thanks both of you.

Is this a problem for anyone else or should I just "get used to it"? I just remember on my Case I could have the RPMs high and move the lever ALL the way and the bucket wouldn't be 'slamming' up or down but would move smoothly and at a reasonable speed.

Phil

MossRoad · Jan 11, 2005

It has been a problem for me once in a while. I ended up with a lap full of dirt. Glad I wasn't working with rocks! /forums/images/graemlins/tongue.gif

May be better to install them and see how you like them. You can always take them out if they are a problem.

J_J · Jan 11, 2005

I just saw some adjustable flow control valves on Ebay for about $5.00. I would get one that matches your hyd flow, and then adjust it down to suit your purpose.

Phils · Jan 11, 2005

Thanks, JJ. You'd think I'd have learned by now to check eBay for everything, but for your suggestion I wouldn't have.

There are two styles (manufacturers) Parker and Flutec. Both are adjustable and mention for single direction rams, so I'd need two of them for the bucket control. One mentions it'll work up to 5 gallons per minute flow. I'm only guessing that flow would be sufficient for my PT bucket. But at a starting bid of $5 each + shipping, I wouldn't be spending more than $25 for them both. Another $5 or $10 for fittings and/or adapters should finish the job. I REALLY like the "adjustable" part and hadn't even thought of that concept. Guess that's why I come to TBN, unlike the rest of you all -- who just come here to SHARE your knowledge with the half-dozen of us that need it!

I'm "watching" those valves and now that I've seen them I'll look at the PT and imagine a good mounting location.

Phil

J_J · Jan 11, 2005

You would only need one flow control in line with a cylinder. The hyd fluid has to go through the flow control to push the cyl out, and then it has to come back through the flow control to return because the fluid on the other side of the piston is pushing the fluid in reverse

There are other valves that restrict in one direction and give full flow in the other direction.

To give flow control to two cys at the same time as in loader arms, you would install the flow control at the point where it comes out of the valve and then splits to each cylinder.

Hope this helps in some way.

FOURTEEN · Jan 12, 2005

"" using the FEL is a touchy proposition ""

There is an OEM lever on the left side of the control panel which is labeled "Throttle"! When a slow gentle touch for the FEL is needed, move that lever toward you until the desired response is achieved!!

/forums/images/graemlins/blush.gif /forums/images/graemlins/smile.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/cool.gif /forums/images/graemlins/smirk.gif

johara1 · Jan 12, 2005

Fourteen, you hit the nail on the head !! /forums/images/graemlins/laugh.gif /forums/images/graemlins/tongue.gif

Phils · Jan 12, 2005

"There is an OEM lever on the left side of the control panel which is labeled "Throttle"! When a slow gentle touch for the FEL is needed, move that lever toward you until the desired response is achieved!!" 

The problem gets WORSE the farther that lever is moved TOWARD me. Moving it away from me causes the FEL action to slow to a more acceptable rate. Because of other HP requirements, sometimes I need the RPMs higher (lever MORE towards me) and that's when the speed of the FEL movement starts getting 'touchy'.... meaning I have to move the hydraulic lever very carefully. Too far and the bucket is slamming up or down and, as was said earlier, I could end up with part of a bucket load in my lap.

I mentioned the old 580 Case I used to have. I'm learning to use the PT ok, despite the fact that the bucket movement lever works in the opposite ways that the Case did. A friend that owns a couple of tractors tried the PT last Sunday and noticed the same thing (bucket movement is controlled just the opposite of how his FELs are).

I just want to SLOW the action down when I'm at full throttle. Looks like the adjustable restrictors could be the answer.

Can any of you tell me the size of the fittings for the hydraulics (1/4 or 3/8 or ?). I'm size-sight impaired (in other words, I have to take three wrenches when I've eyeballed a nut as I never bring the right size the first time if I take only one).

Phil

J_J · Jan 12, 2005

I totally agree in what you are trying to do. That's why I recommend the restrictors. There are times when you need max power to the wheels, and fine control with the FEL, and with a restrictor in the FEL circuit, you can do both. If you also put a solenoid valve in the circuit, the restriction could be switched on and off, giving you total control.

J_J · Jan 12, 2005

I believe the cylinders fittings are 1/4, and the PTO is 1/2, and the wheel motors might be 3/4. Those numbers do not reflect the size wrench you would use. I always take a wrench set plus an adjustable.

Phils · Jan 12, 2005

Thx again, JJ.

The FEL fittings I was guessing to be 1/4 " and that's what the sizes are on the eBay adjustable restrictors. I'll start bidding and see if I can score a couple, since they reduce flow going one way but provide full flow the reverse way I'll need two in order to control both movements.

I'll post when I eventually get them installed.

Phil

MossRoad · Jan 12, 2005

I'm learning to use the PT ok, despite the fact that the bucket movement lever works in the opposite ways that the Case did. 

Swap the hoses! /forums/images/graemlins/laugh.gif

Phils · Jan 12, 2005

"Swap the hoses" 

Actually I thought it was just ME (since I sold that Case a decade ago) until my friend said the same thing. I'm 'relearning' that movement and it's now only a problem for people like my friend (and there was no damage done to his utility bed nor my bucket /forums/images/graemlins/grin.gif). When I install the restrictors I may consider swapping the hoses as I'll be changing lengths or how they run to fit the restrictors in. At least those hoses are VERY easy to access!

Phil

BigEddy · Jan 13, 2005

I haven't seen a PT - so I don't know if there is anything unique about it's SCV implementation. Typically on other units, pulling the lever backwards raises the arms, pulling the lever left tilits the bucket up.

It could be that the hoses are wrong. Some tractors have built in restrictors in one circuit or another. If you have hoses interchanged, then you could be getting poor performance on the bucket and super fast response on the lift, or vice versa. Other PT owners chime in here.

I know my 855 has a restrictor disc in the hose for the loader arms - according to the loader manual it is to slow the drop rate of the loader and prevent cavitation.

MossRoad · Jan 13, 2005

The PT400 series has extremely fast hydraulics on the curl/dump. Especially toward the ends of the travel, where the speed is increased. I think is is probably due to the geometry of the mechanicals that this speed is amplified at either end of the throw. If you put forks on, you can take a railroad tie and actually throw it 8-10 feet out in front of the tractor as if the forks are the flippers on a pin ball machine. They are that fast. Adjustable flow restrictors might not be a bad idea. You could then adjust them to your preferences.

MuncyBob · Jan 13, 2005

Since I never had a tractor with FEL I guess PT movement just seems natural to me....what you don't know won't hurt you?? /forums/images/graemlins/grin.gif.....I have not had any problems and the only quick movement with the bucket that I have noticed is when it totally releases at the end of the dump cycle, but then I've had plenty of practice with the bucket... having the horses around gives me plenty of practice & dumping material! /forums/images/graemlins/tongue.gif

johara1 · Jan 13, 2005

i run equip. for a living for 40 years and the pt. control is the same as all new cat,jd..case,and all other small loaders.580 a,b,c,d,e, through k are the same.i don't know what your friend has that would be different, unless it's a high lift(tracks) and has two leavers. i can't see a need for these valves,check the pressure, see if it's too high. half throttle is all i need in most cases.i agree it's hard to get use to,but it's ok,but what i think is wrong is the fact that you bounce around when you try to use it at full throttle.most all big loaders have a arm rest to steady your hand so it doesn't let you jerk the leaver. /forums/images/graemlins/laugh.gif /forums/images/graemlins/tongue.gif