Go BottomMy 634 CAN t-Fitting
 | TomG
Join Date: Feb 2002 Posts: 5406 Upper Ottawa Valley 
|
2002-05-09 38355
I don't have the fitting, and the price is the reason I'm trying to avoid one. The fitting is needed to carry out a manual procedure for adjusting the power steering pressure relief valve on my 1710. I suppose there are other ways of carrying out the procedure, and I'd sure like to hear suggestions, but I'd like to stick to the manual.
The manual procedure is to remove an elbow fitting in the tube and replace it with a t-fitting so a pressure gauge can be attached. I thought maybe an elbow could be made into a t-fitting by threading or brazing a nipple for the gauge into the fitting body.
A counter guy at a hydraulics shop doesn't think that would work because there's not enough material in the fitting body. I'm inclined to agree with him, but I'm interested if there are contrary opinions. The new elbow I got ($36) is a real jewel. It has 1/8" NPT on one side that goes into the priority valve and mystery metric on the other for the tube fitting. I suppose it’s also a mystery metric tube, and there isn’t a set of flaring tools for to work on it except 200 miles away at the dealer. Maybe not even then.
Reply to |
Quote Reply |
Add PhotoMy 634 CAN t-Fitting
| Mrwurm
Join Date: Feb 2002 Posts: 184 South East Michigan 
|
2002-05-09 38359
Tom, I have read your comments on this project in the past. Can you explain what situation you are trying to improve with this relief pressure adjustment. Just curious.
Also, I recently purchased a NH TC30 which is basically a carryover from the 1620, 1710 machine. I have found that the power steering does'nt have enough power to turn the wheels with the FEL loaded if I am sitting still. If I have a little forward or rearward motion then I can steer just fine. Is this how your steering behaves?
Jerry ....
Reply to |
Quote Reply |
Add PhotoMy 634 CAN t-Fitting
 | Art White
Join Date: Jan 2000 Posts: 6898 Waterville New York
 Pics
|
2002-05-09 38365
Tom it's good to try different things with tractors but the engineers do a good job of trying to get the most out of what they build to begin with. Mind you they are human to and sometimes miss the mark. I would be worried that your modification might give less flow to another area that requires it and that is why they built it the way they did. The NH tractors are noted for lack of steering with loaders as well as for there hydro's. You might make a slightly weak area extremely weak for you in another area. ....
Reply to |
Quote Reply |
Add PhotoMy 634 CAN t-Fitting
| TomG
Join Date: Feb 2002 Posts: 5406 Upper Ottawa Valley
|
2002-05-10 38417
Thanks for the comments. Actually, I'm just trying to do a standard check and adjustment as described in the repair manual. The procedure calls for replacing an elbow fitting in the PS line with a t-fitting so a pressure gauge can be connected. The standard elbow is replaced after the test. I have given some thought to plugging the fitting for a gauge and leaving the adapter mounted permanently, but Art's comments are very well taken.
It's a simple standard test that I should be able to do myself. I'm mostly trying to avoid paying a pretty outrageous price for a 2-bit fitting mostly because NH calls it a special tool rather than a fitting.
Jerry: My steering works as you describe. It is power assist rather than true power steering, and it's not very strong. I've learned to straighten the wheels before coming to a stop and to keep a heavy implement on the 3ph when doing heavy loader work. Even so, I have found myself in shallow excavations with the wheels cramped and unable move or straighten the wheels. The solution is to use loader down-pressure to take some weight off the front.
I've adapted to the steering OK and it's not a big problem for me. However, there is a pressure relief valve adjustment on the steering sector, and if it's low the steering won't be as strong as it could be. I thought the steering had deteriorated over the winter and wanted to perform the test before checking anything further. The steering may be weaker than it should be, but I now think nothing much has changed other than I was running lower than usual tire pressures this winter. Guess it’s inertia, but I still want to do the test.
....
Reply to |
Quote Reply |
Add PhotoMy 634 CAN t-Fitting
| David Waite
Join Date: Jun 1999 Posts: 43
|
2002-05-10 38419
How much metal is in the elbow. My idea would be to tap it out to the thread of pressure gauge use a good sealant and be careful yo did not take to much metal to tap as it might rupture under full pressure. So if it is a big elbow I might try that. Just rap an old pair of jeans around it tight in case it lets loose it will keep it from flying around. ....
Reply to |
Quote Reply |
Add PhotoMy 634 CAN t-Fitting
| TomG
Join Date: Feb 2002 Posts: 5406 Upper Ottawa Valley
|
2002-05-10 38426
Thanks for the comment David. The elbow body is just over .5" so there's not a lot of metal there. That's the same issue counter guy seized on. Another idea might to braze a fitting on. The counter guy sort of waffled about that one so I guess he doesn't actually know.
I suppose another way might be to tap a very small fitting into the elbow since the line to the gauge doesn't carry much flow. I think all my taps are well rusted by now and I probably wouldn't have a tap for a small pressure thread anyway. Maybe a machine shop could give me a better read on the feasibility and would have the right tap in good condition as well.
As you say, if it doesn't work it's going to spring a leak and that shouldn't be a big problem. Well, I have acquired a little wisdom over the years. I think I'll make sure the old elbow can be removed without breaking it before doing any modification to the new elbow I have.
....
Reply to |
Quote Reply |
Add PhotoMy 634 CAN t-Fitting
| pbenven
Join Date: Jul 2003 Posts: 38 Southwestern Quebec, Canada
|
2002-05-10 38427
How are your machinig skills? Would it be feasibile for you to just get a block of metal and drill/tap the holes yourself? Forgive me if I'm oversimplying, but I have no idea what part you're talking about (not for the lack of your description, but for my ignorance of tractor hydraulics). ....
Reply to |
Quote Reply |
Add PhotoMy 634 CAN t-Fitting
 | Murf
Join Date: Dec 1999 Posts: 7249 Toronto Area, Ontario, Canada
Pics
|
2002-05-10 38433
Tom, let me know the spec.'s and I will call my local (really big) hydraulic shop, I cannot imagine an elbow being even 10% of that price, even if it was painted Orange...LOL...I am surprised that an elbow is even needed, most power steering systems I have seen have a port for such occaisions built right in. Best of luck. ....
Reply to |
Quote Reply |
Add PhotoMy 634 CAN t-Fitting
| TomG
Join Date: Feb 2002 Posts: 5406 Upper Ottawa Valley
|
2002-05-11 38464
David: My machining skills are rudimentary at best. My father-in-law does have some equipment including a South Bend lathe. So at least I could use equipment that is far beyond my skills.
Thanks Murf: One problem I have is determining the specs. I bought the $36 elbow so I could figure out the threads on the $634 adapter. The trouble is that a counter guy in Prembroke couldn't identify the threads on the pipe end of the elbow--metric probably.
I suppose one option is mailing the elbow to a big hydraulics shop and seeing what they can do. My dealer in Arnprior uses a shop in Ottawa. I can't remember the name exactly but part of it sound like 'free.' Don't suppose that refers to prices though. If you know of another shop, I'd sure like to hear of it. Note: these place names may be unknown to everybody except Murf and myself.
I hope this thread illustrates some of the difficulties working with various international standards and factory parts systems. There also is a maintenance issue here. A very easy thing for me to would be to turn up the relief valve pressure and see if the steering becomes stronger. I could count the number turns of the screw adjustment so I could return the adjustment to its original location. Scribing index marks would help the accuracy, but I still wouldn’t know the adjustments sensitivity. A little off could equal a sizable relief pressure difference.
However, I’m not going to fiddle with the adjustment without a pressure gauge. The problem is ‘What if I turn the pressure up and the steering is stronger? Have I corrected a low relief pressure or have I compensated for bad steering parts with high hydraulic pressure? No way of knowing that I can figure.
....
Reply to |
Quote Reply |
Add PhotoMy 634 CAN t-Fitting
| Art White
Join Date: Jan 2000 Posts: 6898 Waterville New York
Pics
|
2002-05-11 38465
Tom it is to bad that you have to see some of what it costs to keep a dealership open to check your tractor. Maybe your dealer would let you rent his tool for a few days to play with on your own. Many of the tractors built today for a dealer to sell, will have to buy several thousand dollars of special tools before the first dollar is made in selling them. I'm not talking about compact tractors here but the larger ones. Some of the newer ones with the computers on board we can only lease the special tools from the manufacturer. Your problem is not unique to your tractor and is the way the tractor is built I believe as You are not the first that I've heard of this problem from. You might be able to enlighten the board to a solution if possible and I would like to know it too. Just be sure you are not taking away or over powering something that is not built for your change so to harm another function. ....
Reply to |
Quote Reply |
Add PhotoMy 634 CAN t-Fitting
| TomG
Join Date: Feb 2002 Posts: 5406 Upper Ottawa Valley
|
2002-05-11 38468
As usual Art's comments are very well taken. I had problems similar to dealers when I had a sideline sound and lighting company. To do the work well and keep the equipment reliable, a bunch of gadgets are needed. They are expensive and don't get used often enough to be very happy about having to have them. Customers aren't too happy when gadget costs are folded into prices but they are even less happy if the sound is bad or unreliable. The other point I also completely agree with. I’m not intending to modify the system or perform adjustments without proper test gear.
I probably will run the problem through a large hydraulics shop just to see if the adapter I need can be made or found in a catalogue at reasonable cost. The most likely result is that I'll just wait until the tractor needs to go to the dealer for something else and then have my dealer sort it out. It's sort of a tough call between buying expensive special tools so I can do the work myself or shipping the tractor nearly 400 miles round trip. Fortunately, the steering works acceptably right now.
....
Reply to |
Quote Reply |
Add Photo
Go Top
Share This