Safety Valve

[RICK IN GA]

I see there is a difference between the lift cylinder safety valve on the NAA and 8N and 100 Series+. This site doesn't show safety valve for my NAA. Are any of these others ok to use?

 

[TheOldHokie]

(quoted from post at 10:18:30 01/26/12) I see there is a difference between the lift cylinder safety valve on the NAA and 8N and 100 Series+. This site doesn't show safety valve for my NAA. Are any of these others ok to use?

The part number for the NAA relief valve is NAA-638E. It is not the same as the 8N-638 valve used on the N-series. NAA-638E is available from Just 8N's- $63.

TOH

 

[JMOR]

(quoted from post at 10:18:30 01/26/12) I see there is a difference between the lift cylinder safety valve on the NAA and 8N and 100 Series+. This site doesn't show safety valve for my NAA. Are any of these others ok to use?

on't mean to pick 'nits' here, but Rick, you asked about a "lift cylinder safety valve" & the 8N has a system over pressure relief valve (it would open by overpressure between the pump & lift cylinder), relieving both the cylinder & the pump. Whereas the NAA has both a hydraulic pump safety/relief valve (TOH gave you the number) AND it has a ram cylinder/lift safety valve (NAA984F), two separate parts. 638 is in belly of tractor hyd compartment and 984 is on lift cylinder/valve assembly attached to top cover.

 

[RICK IN GA]

I believe the one I'm talking about is NAA984F. For the later Series Fords they used NCA984F according to my Parts Catalog. Does this site have the NAA984F?

Thanks

 

[JMOR]

(quoted from post at 12:16:57 01/26/12) I believe the one I'm talking about is NAA984F. For the later Series Fords they used NCA984F according to my Parts Catalog. Does this site have the NAA984F?

Thanks

id not find it listed on the YT site. The {C3NN984-A} 1955-64 Valve(Lift Cylinder Safety) is listed for 1955 - 1964 on another site, but I have no idea as to whether it will fit your tractor or not. Call toll free 1-888-355-9937 and those folks will be able to answer that question.

 

[TheOldHokie]

(quoted from post at 12:07:06 01/26/12)

(quoted from post at 10:18:30 01/26/12) I see there is a difference between the lift cylinder safety valve on the NAA and 8N and 100 Series+. This site doesn't show safety valve for my NAA. Are any of these others ok to use?

on't mean to pick 'nits' here, but Rick, you asked about a "lift cylinder safety valve" & the 8N has a system over pressure relief valve (it would open by overpressure between the pump & lift cylinder), relieving both the cylinder & the pump. Whereas the NAA has both a hydraulic pump safety/relief valve (TOH gave you the number) AND it has a ram cylinder/lift safety valve (NAA984F), two separate parts. 638 is in belly of tractor hyd compartment and 984 is on lift cylinder/valve assembly attached to top cover.

OK - I'm confused - nothing unusual there :roll: If the control valve has an internal relief why do you need the NAA-638 relief in the supply line? What is it protecting against and how? When I looked this up in the parts book the first time I went to the control valve assembly and saw the NAA-984 but description says it is a check valve.

TOH

 

[RICK IN GA]

I am surprised that this question has not found an easy answer. I called nnalert and they were baffled too. I just got off the phone with the parts dept from this site and they were baffled as well.

I'm thinking I want to change my question as a result of the responses. Can this valve be cleaned well and reused? I have no indication that it was a problem to begin with.

 

[JMOR]

(quoted from post at 16:40:09 01/26/12) I am surprised that this question has not found an easy answer. I called nnalert and they were baffled too. I just got off the phone with the parts dept from this site and they were baffled as well.

I'm thinking I want to change my question as a result of the responses. Can this valve be cleaned well and reused? I have no indication that it was a problem to begin with.

robably just re-use it. If you could find a way to connect a pressure source to it, you could see that it holds at <2700 PSI & relieves at 2700-3000PSI. Why are they "baffled'? Can't find number or what?

From CNH parts list:
21 1 NAA984F CONTROL VALVE Valve Assy., Hydraulic Lift Safety, Years: 01/01/1953-12/31/1954

http://agriculture.newholland.com/us/en/Parts-and-Services/Parts-and-Services/Pages/default.aspx

 

[TheOldHokie]

(quoted from post at 16:40:09 01/26/12) I am surprised that this question has not found an easy answer. I called nnalert and they were baffled too. I just got off the phone with the parts dept from this site and they were baffled as well.

I'm thinking I want to change my question as a result of the responses. Can this valve be cleaned well and reused? I have no indication that it was a problem to begin with.

To paraphrase JMOR - "if it ain't broke don't fix it until it is". JMOR and I have had a little offline discussion about this and the cracking pressure is something like 3000 PSI. If you aren't transporting 1000# bales on a 3pt spear unlikely it ever opens.

TOH

 

[RICK IN GA]

That's definitely what I'm trying to get my hands on whether I need to or not I just called my NH dealer and he said it was discontinued but put me in touch with a rural salvage guy that actually said he has one for $55. He said they're "Like Gold". :-0

Still think I wanna see whether it can be cleaned or if that is a bad idea. I was hoping that Zane would chime in here. I am the proud owner of a ZANE THANG.

 

[RICK IN GA]

At nnalert the 8N-638 looks just like it, but the other one NAA9** looks completely different and says it is only for 55+ models.

 

[JMOR]

(quoted from post at 17:32:30 01/26/12) At nnalert the 8N-638 looks just like it, but the other one NAA9** looks completely different and says it is only for 55+ models.

ow, you have me wondering which valve you are talking about??? First picture or second picture (lower left, next to supply tube)?

 

[TheOldHokie]

(quoted from post at 17:30:04 01/26/12) That's definitely what I'm trying to get my hands on whether I need to or not I just called my NH dealer and he said it was discontinued but put me in touch with a rural salvage guy that actually said he has one for $55. He said they're "Like Gold". :-0

Still think I wanna see whether it can be cleaned or if that is a bad idea. I was hoping that Zane would chime in here. I am the proud owner of a ZANE THANG.

Personally I wouldn't hesitate to flush either one good and put it back in as long as I had no reason to think it was leaking. As I understand it the "like gold" NAA-934x serves two purposes

• [*:9631c8ca24]It acts as a backflow check on the pump supply line and has a cracking pressure of ~150 PSI.[*:9631c8ca24]It acts as a 3000 PSI over pressure relief for shock induced pressure spikes in the lift circuit when there is a raised load and the valve is in neutral.[/list:9631c8ca24] If the valve were truly defective rendering the lift unusable and no replacements are available seems to me it would be right easy to make a simple spring and ball type check valve to fit that port for function (1). Then for (2) plumb the backside of that check valve to an externally mounted OTS 3000 PSI relief valve of your choice.
  
  TOH

 

[ZANE]

It is strictly a pressure relief valve. Does the same thing as the 8N 638 B in the 8n. It is not a check valve. The only check valve on the NAA is the back pressure relief valve and tube.

I have opened up the NAA valves and sometimes found a piece of foriegn material in the ball and seat keeping it open. Clear this out and it will be good as new if the ball and seat are not eroded. Over time the ball and seat can become eroded and cause leakage. A new ball of the same size can be used and I have taken a wooden dowel and vavlve grinding compound and resurfaced the relief valve seat on several relief valves with mixed results.

Zane

 

[JMOR]

(quoted from post at 20:32:16 01/26/12) It is strictly a pressure relief valve. Does the same thing as the 8N 638 B in the 8n. It is not a check valve. The only check valve on the NAA is the back pressure relief valve and tube.

I have opened up the NAA valves and sometimes found a piece of foriegn material in the ball and seat keeping it open. Clear this out and it will be good as new if the ball and seat are not eroded. Over time the ball and seat can become eroded and cause leakage. A new ball of the same size can be used and I have taken a wooden dowel and vavlve grinding compound and resurfaced the relief valve seat on several relief valves with mixed results.

Zane

hich of the 2 in my pictures above are you talking about, Zane?

 

[RICK IN GA]

Thanks Zane!

 

[RICK IN GA]

Thanks JMOR It is definitely the NAA984F. It is in good shape with no noticeable corrosion. My back pressure valve you noted above moves freely, I took it out and cleaned it well. My control valve will just need to be cleaned up. The confusing thing is that the 8N model pointed out by Zane looks just like the NAA984F. My thought was.....same valve.....different model (The 8N version is readily available), but since no one is sure looks like ill save a few buck and clean and reinsert. Thanks again! Rick

 

[JMOR]

(quoted from post at 21:06:44 01/26/12) Thanks JMOR It is definitely the NAA984F. It is in good shape with no noticeable corrosion. My back pressure valve you noted above moves freely, I took it out and cleaned it well. My control valve will just need to be cleaned up. The confusing thing is that the 8N model pointed out by Zane looks just like the NAA984F. My thought was.....same valve.....different model (The 8N version is readily available), but since no one is sure looks like ill save a few buck and clean and reinsert. Thanks again! Rick

K, but down in the hole that you un-screwed that valve from IS the CHECK valve spring & ball. Might want to examine it too.