Tractor- Ford NAA ,has a loader make unknown, front mount hyd pump. Loader valve is two spool, main cylinders are one way, bucket cylinder is two way. Valve is mounted to the right frame that is also the hyd reservoir. The return is routed straight into the frame/ reservoir. The leak is on thr pressure side of the main cylinders, 3/8 inch pipe threads.I replaced the 3/8 street elbow with a new one (steel) , used a pipe dope from a tube w/ teflon. Still leaks and am afraid to try turning another 360 degrees ans crack the valve itself. I ordered a brass elbow for tomorrow thinking the softer metal would seal better. Question is, what kind of pipe dope should I use? thanks joe
- Thread starter old-9
- Start date
onefarmer
Well-known Member
- Location
- 6735 S Lowell Rd, St Johns, Mi 48879
Brass elbow? It's not going to stand the pressure is it? I wouldn't trust it.
One question was that new street elbow made in China ? Put a new two spool controls on my loader a few years ago and bought some new pipe fittings (China) and could not get them to stop leaking. Went down to hardware store and found American made fittings and every one of leaks stopped. A close look at the Chinese made fitting and found they had imperfections in threads.
Are you using a hardware store elbow? seems like I have had trouble with pipe thread matching. they work ok as in threaded into like fittings, but seems like some china fittings don't like thread pitch. See if you can get a regular hyd.shop item. might even find a tough automotive one. brass maybe too soft.
Brass elbow "MAY" hold the pressure that there is in that system. You would be better to stick with steel. You can either use a better sealant, or you may be able to use a better fitting setup. Is there enough room to put a straight NPSM steel hydraulic swivel and a street hydraulic elbow? If you want a better sealant, Loctite 545 works very well. Also get some of the cleaner/primer. The fitting needs to be clean, then the loctite, and let it set up.
Andy Martin
Well-known Member
Dope should be used to lubricate the threads, not really to seal them. If the street ell threads look good, you may find they are cut too long. Try grinding the end of the male part of the ell if it looks like the threads may be bottoming out. If the thread is short you might try using a pipe die on it to cut a little more thread to allow you to get another turn. I had a bunch of pipe fitters threading 2" pipe one time, and I could tell they had cut the threads too deep, and told them so. They knew I wasn't a pipe fitter so knew nothing until all their joints leaked because the threads bottomed out before sealing.
Otherwise, get a close nipple and a conventional ell, you'll have two joints to help with the number of turns to get it tight.
Otherwise, get a close nipple and a conventional ell, you'll have two joints to help with the number of turns to get it tight.
The steel elbow is hydraulic rated , and one of the other elbows is also brass and no problem holding the pressure. My plan is to remove whole valve ( so I can clean it out well) and run a 3/8 inch tap very easy. going to look for pipe dope / thread sealer and reassemble. I will also check on regular 90 elbow and nipple. thanks for the inpuit joe
Steve@Advance
Well-known Member
Look the valve thread over carefully, it may already be cracked.
If you are using the machined steel fittings, that is about as good as it gets.
Be careful tapping it deeper, you want to have 6 threads left showing on the tap. Go any deeper and the fitting will bottom before it gets tight. Some heavy grease on the tap will help trap shavings.
Some teflon tape may help seal the threads. Some don't like to use teflon tape on hydraulics, but this system is so basic it can do little harm. Keep it away from the end of the fitting, it may be just enough to seal it.
If you are using the machined steel fittings, that is about as good as it gets.
Be careful tapping it deeper, you want to have 6 threads left showing on the tap. Go any deeper and the fitting will bottom before it gets tight. Some heavy grease on the tap will help trap shavings.
Some teflon tape may help seal the threads. Some don't like to use teflon tape on hydraulics, but this system is so basic it can do little harm. Keep it away from the end of the fitting, it may be just enough to seal it.
Similar threads
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.
Copyright © 1997-2024 Yesterday's Tractor Co.
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.
Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy