New Holland (Prince) Loader Valve Will Not Stay In the Float Detent Position

[toot77]

I have a 2010 New Holland T1520 with the 110TL loader. The OE loader valve is a Prince valve. My problem is that the valve will not stay in the float detent position when using my front snowblower. I have owned this tractor for the past 2 years.

I also have a 1995 New Holland 1520 (which is what I have used the snowblower for the previous 27, or so, years. The OE loader valve on the 1520 is a KYB Kayaba valve. While it has worked fine, i.e. usually stays in float, I do have a 1993 service bulletin for the Kayaba valve that my dealer gave me in 1997 that describes adding a 0.075” shim to the detent spring to improve keeping the valve in float detent by adding 8 lbs force to it. I must have questioned it once way back. I do not recall if I made the service bulletin mod.

My question is; is there a comparable mod that can be made to the Prince valve to make it stay in float detent? The Prince's detent does not look like the Kayaba service bulletin diagram.

The prince valve casting number looks to be C-689 Rev G, but is hard to read.

 

[Harry in Ky]

I think if you have the pertinent information on the valve, you should try to contact Prince with your question. Maybe through a Prince dealer or distributor if all else fails. While you may well get some responses here, I rather doubt any will be all that helpful. Maybe I'll be surprised.

 

[rScotty]

If you post a photo of the valve assembly we should be able to identify the float detent part of your FEL valve set. Take several views.
The float detent "latch" is pretty obvious on most FEL valves and is essentially a rod-like extension on the far end of the loader arm valve spool. That extension lives in a metal cannister where it ngages a trapped ball and spring detent mechanism.

If yours is the simple type, it is routine maintenance to clean the dirt and rust out.

In most valves, that float detent assembly enclosed in that cannister that has a weep hole at the end. That weep hole is the problem because it can also let water and dirt into the cannister. The right cure is to take the cannister off, clean and polish the rod, detent ball or cam face, and check that the spring is still good. As you found, some can be shimmed - but clean it first.

The "set of pants cure" is to squirt some WD-40 into that weep hole and see if that helps.....

First things first- get some photos so we can confirm.
luck,
rScotty

 

[toot77]

Here are some photos of the valve.

The New Holland part number is 86535713. From other older posts here, and from Prince info online, it appears that the closest stock Prince valve might be a LVTR series valve. A Skematic from New Holland parts shows the cross section of the valve.

The float detent looks different from the Kayaba valve. On the Kayaba valve, according to the old New Holland service bulletin, a washer can be added to the detentions spring which is easily accessible inside the rear cap. The Prince valve detent spring looks to be buried behind the detent parts.

I am curious if adding shim(s) to the detent spring on the Prince valve will help keep the valve in the float position when using my front snowblower?

EDIT: the attached NH SB is apparently not for my Kayaba Valve. My Kayaba valve have a detent similiar to the Prince except that it does have 4 balls vs Prince's 2, and the Kayaba valve has a fifth slightly larger ball in place of the Prince's cone. The Kayaba valve has a very similiar spring to the Prince valve that pushes on the fifth ball in the same manner as the Prince spring pushes on the cone.

 

[toot77]

To add, the tractor has 540 hours and I believe it was pretty well taken care of prior to my buying it. I think the valve should be in pretty good shape. I did remove the rear cap on that spool and can see the back end of the detent assembly. It looks clean, I did not try to remove anything else until I have an idea of what may come flying out and what to watch for. I will do some checking in the area and see if there is a Prince rep who might talk to me about this.

 

[the old grind]

Between us we have cutaways of two different valves. One uses the center spool and one uses the spool opposite the relief valve for lift. Both show a similar location to add the .075" shim but IMO the SB is confusing compared to the cross-section view(s) we have.

#17 is the spring that the spacer would go (inside #16) behind/between #18, but on #7 spool vs #6 as shown above depending on which is lift. I can scan pics & a snapshot of disassembly instructions from the T1520 manual. (Section 35)

btw, My FEL is overdue for the same fix, so expect me to jump in soon. Should only have to remove the cover & one end cap. And THANKS for bringing this up with a thread title that's to the point and will let us get the news out there to others.

 

[rScotty]

To add, the tractor has 540 hours and I believe it was pretty well taken care of prior to my buying it. I think the valve should be in pretty good shape. I did remove the rear cap on that spool and can see the back end of the detent assembly. It looks clean, I did not try to remove anything else until I have an idea of what may come flying out and what to watch for. I will do some checking in the area and see if there is a Prince rep who might talk to me about this.

Thanks for the beautiful photos and diagrams. Looks like you washed it!

First of all, a couple of things caught my attention. My apologies for the initial digression, but it's a price you pay for hobby advice on TBN.

One initial impression is that the spool valve assembly casting is oddly crude compared to most Prince components - although the machining you can see on the spools and connections seems to be Prince's typical high quality. I wonder why that is?? It doesn't mean anything, just seems odd.

And secondly I am still fascinated by the way the designer using the Prince valve solved the problem of moving two spools with a single lever. It works, and is wonderfully simple. In fact it looks like like something from a vintage mechanical motion textbook - or an old issue of Popular Mechanics. Most single levers today use some sort of a rotating ball mechanism in order to keep the spool forces equal, but the version shown would certainly work.

And last digression is just aesthetic. When I look at the one-dimensional cutaway view of the Prince valve, and then compare it with the artist's exploded view of the KAYABA valve below it - the one with the A,B,C components - I am nostalgic for those days when mechanincal shop drawings included a real artist working at visualizing and drawing 3-D views of exploded mechanisms.

None of this would have been obvious without those great photos and scans. Thanks again.

Anyway, here we go. I agree with how "the old grind" descibes the functions of the springs, spools, and detents in that cutaway view. And I don't see my expected weephole. Maybe it is internal or built into the sliding tolerance between parts? Maybe so, we know there has to be some way to vent or drain the void at the far right hand end. Old valve sets had an external weephole to vent to the outside, but apparently not this one. Bottom line is that easy solution #1 is not applicable. And anyway, you took the end cap off and any problem - like dirt or even hydrolocking - would have been obvious if it was there.

Easy fix #2:
Before we go on ... can anyone tell me what that piece is numbered 8,9,10,11, & 30? in the LVTR series valve? Is that the PB sleeve? I don't understand it and need to make sure it is not a restriction on rotating the spool valve. The reason is that my easy fix #2 "revolves" around an assumption that the hidden part of the spool valve has radial symmetry - i.e. that the part of the spool within the valve casting as well as the spring and detent groves are a 100% lathe-turned part. If so, the only thing preventing the spool valve from rotating is the actuating lever fastened to the flat milled on the near end of the spool valve. .

So easy fix #2 goes like this: With the engine off and ALL pressure released from the loader, mark the top of the spool valve at the lever, then unbolt the actuating lever from the end of the spool valve. Now the spool valve should be able to be rotated within the bore. Don't move it in and out, just try rotating that spool valve however much seems reasonable to break up any crud and stiction it has from operating in the same positon for decades, then finally rotate it 180 degrees out from the original position and hook up the lever again.
What do you think?

rScotty

 

[the old grind]

The odd bits are a check valve that works with regen & float. (8-11 & 30) Seven pics in the manual show flow to cyls in operating positions for curl and lift. Each one shows flow through or around the poppet according to control position.

 

[the old grind]

Staying in float requires a cone & spring 18, 17 to hold the four balls into the annular recess in the cap and keep the sleeve 16 in position until manually retracted. We just need to shim up 17 for more push to hold the balls in place better. Can be done in situ & no further tinkering needed, really.

 

[dicktill]

Thanks for the beautiful photos and diagrams. Looks like you washed it!

<snip>

So easy fix #2 goes like this: With the engine off and ALL pressure released from the loader, mark the top of the spool valve at the lever, then unbolt the actuating lever from the end of the spool valve. Now the spool valve should be able to be rotated within the bore. Don't move it in and out, just try rotating that spool valve however much seems reasonable to break up any crud and stiction it has from operating in the same positon for decades, then finally rotate it 180 degrees out from the original position and hook up the lever again.
What do you think?

rScotty

I have an idea if @rScotty's fix #2 doesn't work. Almost certainly the cap on that spool is a soft alloy, not steel. If so, over time, the balls could easily have worn away the "sharp edge" on the detent groove. Perhaps all you need is a new cap.

 

[the old grind]

I have an idea if @rScotty's fix #2 doesn't work. Almost certainly the cap on that spool is a soft alloy, not steel. If so, over time, the balls could easily have worn away the "sharp edge" on the detent groove. Perhaps all you need is a new cap.

My T1520 has had this issue since I bought it new off the lot. I've always had to hold the stick in float and the detent is barely detectable when going into it. Stiffening 17 by shimming is kinda obvious isn't it?

Anyway, don't remove the cap by itself, lest the balls fall out. Loosen the two long bolts and remove the cap and outer sleeve to bench the sub-assembly. Be sure that 16 slides out with the the cap, sleeve, & outer spring all together.

 

[rScotty]

My T1520 has had this issue since I bought it new off the lot. I've always had to hold the stick in float and the detent is barely detectable when going into it. Stiffening 17 by shimming is kinda obvious isn't it?

Anyway, don't remove the cap by itself, lest the balls fall out. Loosen the two long bolts and remove the cap and outer sleeve to bench the sub-assembly. Be sure that 16 slides out with the the cap, sleeve, & outer spring all together.

Thanks for the check valve explanation. Looking at designs in detail is always fun.

Back to the detent and a possible stiffening shim, you have the advantage of me with the manual. Details of #17 and #18 are not shown. And as I look, it makes me curious about something else,,,,Why do you think that the cone, spring, and balls are also used in the bucket spool valve that does not have the ridge and and annular space that make a detent? For centering?

Shimming the spring is certainly an answer, but may not be the only one. The detent works because the balls are forced over a ridge. How many balls are there? How are they constrained? Can the number be changed? If so, would changing the number of balls accomplish anything?

rScotty

 

[the old grind]

Cone and four balls are also in the curl spool w/o a lip so that quick dump must be held vs detent to a fixed position. The cap sleeves are different between spools and could be switched with functions/connections but there's also an orifice to move over too. It's under a plug on the top of the valve by the capped end.

16, 17 & 18 are kinda crowded into the top B&W pic in post #4 with numbering arrows pointing to them. Here's another pic from the manual. 16, 17, & 18 are then shown as 13, 21, and 22 with 24/25 being the outer sleeves with groove or not. I call 22 the cone, and it's 21 that's weak and can be shimmed to hold the balls into the groove/lip more securely.

 

[toot77]

First of all, Thank You for the comments and input to my questions here. Much Appreciated!!

I only see 2 balls on each spool in the diagrams for the Prince valve. I also have been trying to understand why the bucket curl spool also has the cone & balls. On this Prince valve the bucket dump function is described as a 2 stage function with the second stage adding regen (I assume that means first stage is without regen). The older 1520's Kayaba valve (according to the description in the 1520 service manual) also has regen on the bucket dump function, but it is not described as a two stage thing.
The information below is for the Kayaba valve, not Prince.

Is it a safe assumption that regen is a pretty standard thing on loader valves for the bucket dump function on compact tractors? I am curious because should shim(s) not help the Prince valve (or I loose the balls in my garage), I do have a spare nos Kayaba valve as a result of an ebay bargain some 16 years ago.

My 1520 has never had a loader on it. It has the 7108 loader valve as part of the front snowblower, so i do not know how well that valve actually works with a loader. Looks like New Holland switched to the Prince valve for the 7308 and 110TL loaders. According to New Holland, the Prince and Kayaba valves are interchangeable although both are listed as obsolete.

Is there any real functional difference between these valves?

 

[the old grind]

Net functions are the same for both valves, just different ways of achieving them mechanically. btw, I had a 7308 FEL on my 98 1520, traded in on the T1520 & never saw which valve was on the former.

The KYB valve/info might only confuse us, & the old SB is in regards to that one. But in both cases it's the force keeping the balls seated that is lacking and the simple cure is to increase it with more spring pressure. That's our only and common issue.

Four balls in the Prince valve but only two show in cross section views, and what looks like a wedge is really cone-shaped. The balls on the curl valve don't have a detented position that stays, but must be held by the operator for rapid dump. Pretty basic and easy to overthink all this, but we'll get there.

 

[jmc]

In case no one mentioned it, Kubota had a rash of loader valve malfunctions that sound like yours and there were several good threads on fixing it if you can search for them.

IIRC, the consensus was that the earlier ones didn't have the weep hole so condensation would rust the detent assembly or freeze up in the winter. Members reported drilling their own weep hole. I ordered the new subassembly and the replacement had a weep hole, so, a design upgrade.

 

[macdoesit]

I have a 2010 New Holland T1520 with the 110TL loader. The OE loader valve is a Prince valve. My problem is that the valve will not stay in the float detent position when using my front snowblower. I have owned this tractor for the past 2 years.

I also have a 1995 New Holland 1520 (which is what I have used the snowblower for the previous 27, or so, years. The OE loader valve on the 1520 is a KYB Kayaba valve. While it has worked fine, i.e. usually stays in float, I do have a 1993 service bulletin for the Kayaba valve that my dealer gave me in 1997 that describes adding a 0.075” shim to the detent spring to improve keeping the valve in float detent by adding 8 lbs force to it. I must have questioned it once way back. I do not recall if I made the service bulletin mod.

My question is; is there a comparable mod that can be made to the Prince valve to make it stay in float detent? The Prince's detent does not look like the Kayaba service bulletin diagram.

The prince valve casting number looks to be C-689 Rev G, but is hard to read.

Mine did the same thing, it would not stay in float. Mine is exactly like yours, I took the blue cover off and noticed it would stay in float position. When I put the cover back on I noticed the joystick was hitting the cover, I took a round rasp and filed the cover down a smidge where the joystick rod was hitting the cover and it now works as it should.

 

[toot77]

Regarding the handle clearance with the cover, I don't think that is an issue. Here are a couple photos of the valve with a cover minus the boot and handle. First is with valve in neutral position

Next is with the valve in the float position

A thought that did pop into my head a bit ago, is whether the length & weight of the valve handle extension is helping to knock the valve out of float. The float detent feels pretty firm when operating the valve without the handle extension. The T1520 valve handle is about 19" long which is 5-1/2" to 6" longer than the handle on my old 1520 (with Kayaba valve fwiw). I know that it is enough longer that it is more in the way when getting on and off the tractor.

 

[toot77]

I jumped into it today and disassembled the float detent. I did remove the valve so I could do it on the bench (at least for first time). It did come apart easily, as I was told on here several times in past few days. (Thanks again for all the input). This is what I found

The balls, cone, and spring were well covered in grease. There as no rust, dirt, grime, scale. There are only 2 balls. Maybe saving the cost of 2 extra balls helped Prince get the New Holland bid from Kayaba??
For anyone else who tries this, I noted dimensions needed to select the shim(s). The 'G' dimension is the size of the largest drill bit that I could easily slide into the bore where the spring sits, so the ideal, or max, shim OD looks to be about .260". I do not think it is necessary for a shim to have a center hole to clear the rod on the back side of the cone. I am thinking to start with .060"-.075" for thickness mainly because that was the recommended shim thickness on the old SB (I know it's different valve but it is a starting guess). If I don't find something around here, I will probably order shims from McMaster.

Also, taking it apart is easy. After removing the rear detent cap and its 2 screws, I just wrapped a rag around the detent collar, including the end, and slid the collar back. Between the rag and the existing grease, nothing acted like it wanted to take flight. Getting it back together, maybe not so easy. The axis of the bore where the balls set is rotated at an angle that I don't have anything to safely pinch them into place while sliding the collar back on. I haven't quite figured that out yet, but thinking of making a plate that I can fasten to the valve base plate with a bolt to function as a jack screw to push and hold the cone in.

 

[rScotty]

Regarding the handle clearance with the cover, I don't think that is an issue. Here are a couple photos of the valve with a cover minus the boot and handle. First is with valve in neutral position
View attachment 2123902
Next is with the valve in the float position
View attachment 2123903

A thought that did pop into my head a bit ago, is whether the length & weight of the valve handle extension is helping to knock the valve out of float. The float detent feels pretty firm when operating the valve without the handle extension. The T1520 valve handle is about 19" long which is 5-1/2" to 6" longer than the handle on my old 1520 (with Kayaba valve fwiw). I know that it is enough longer that it is more in the way when getting on and off the tractor.
View attachment 2123904

Nice idea. Will you be making up a lighter handle just to check?