The gland on my crowd cylinder started leaking around the threads early during my ownership of this machine. The first time I loosened it all the way out, removed the rod pin, and stretched some o-rings into the groove that is supposed to seal it. That worked until the inner seals started leaking so I had to repack it. That was another story that has already been told. Fast forward to now and it started leaking at the threads again. Apparently the tube bore or gland is damaged so the stock seals won’t hold up. I decided to try to do a patch job again since it worked the first time but this time I went even sleazier. I backed the gland out about and 1/8”, cleaned out the groove, and ran a bead of silicone in it then tightened it back down. Of course the damn thing wouldn’t come loose. This gland has had a rough life. The cylinder barrel has obviously been heated and peened and the gland has pipe wrench battle scars all around it. I started with a gland wrench. The pins supplied with the wrench are a pretty loose fit in the gland holes so I upsized those with pins from some standard tractor lynch pins. I replaced the set screws with some ¼-20x3/8” screws because one was damaged and the Allen wrench wouldn’t fit it good. These wrenches would be infinitely more useful if they had hardened pins machined to fit the wrench and gland nut holes precisely. I also put a couple of large washers between the wrench and pull handle so the drive was flush with the side against the gland nut. I positioned the wrench in the gland and used cosamar’s strap trick to try and hold it in place. The nut would still not give in with a cheater pipe and the wrench kept popping out. I finally tried putting pressure on it with the loader on my small tractor but the pull handle still came out of the gland wrench and the wrench kept falling on the ground. I finally gave in and broke out the 3’ pipe wrench. The ratchet strap DID work to hold the pipe wrench square so I could put pressure on it with the loader. That broke it loose. I backed the gland out about an 1/8”, cleaned it out with brake clean, and put a bead of silicone in the groove. Then I tightened it back down but I just used the 2’ pull handle and gland wrench without a cheater. Then I wiped all the excess glue off. Hopefully the glue will keep it from loosening and also seal the leaking threads. I will give it a test tomorrow to see if it leaks.
Maybe an upsize on the thickness of the oring will do the trick?
Assuming your 575e is the same as my 555e. On Messicks the thickness is .139. This one is .210. 50% thicker is my math is right. AS568-347 B70 (NBR) Buna-N Nitrile 70 Duro O-Ring [B70347] : The O-Ring Store LLC, We make getting O-Rings easy! The O-Ring Store LLC AS568-347 B70 (NBR) Buna-N Nitrile 70 Duro O-Ring [B70347] - 4-1/4"ID X 4-5/8"OD X 3/16"CS Buna-N O-Rings 70 Duro (NBR): The most commonly used elastomer for sealing products. Nitrile, also known as Buna-N or NBR, is a copolymer of Butadiene and Acrylonitirle. It has a... www.theoringstore.com
Or if that don’t work go big or go home! This one is .275. Little under double. AS568-423 B70 (NBR) Buna-N Nitrile 70 Duro O-Ring [B70423] : The O-Ring Store LLC, We make getting O-Rings easy! The O-Ring Store LLC AS568-423 B70 (NBR) Buna-N Nitrile 70 Duro O-Ring [B70423] - 4-1/4"ID X 4-3/4"OD X 1/4"CS Buna-N O-Rings 70 Duro (NBR): The most commonly used elastomer for sealing products. Nitrile, also known as Buna-N or NBR, is a copolymer of Butadiene and Acrylonitirle. It has a... www.theoringstore.com
I kind of expect this high temp silicone to hold it. It's pretty durable and oil resistant. My original sleazy repair was two green undersize in diameter o-rings stretched into the groove in place of the stock o-ring and backer. The o-ring diameter was a little thicker than stock but the over all diameter was at least an inch smaller. I got those out of Mazda 3 oil filters. They held until the gland seals in the middle wore out.
Why not take the cyl completely apart and fix it properly? RTV is not an appropriate sealer for any hydraulic leaks
The "backer" in combination with the "O" ring is necessary for a long lasingt leak free assembly. You posted that you cleaned it up, applied the silicone and tightened it down. That would squeeze it all out. The proper way would be to barely tighten it. It needs thin film on it to cure for an hour and then tighten it down.
As stated in the first paragraph. The only "proper" repair for this old cylinder would be a new replacement. Repacking the Crowd Cylinder on my 575E Never a dull day with trying to get parts for this thing. The seal supplier came up with three possibilities for a kit so I bought all three with the understanding I could return the two I didn't need. None of them have what it would take to repair this. I have a message in to the supplier with... HeavyEquipmentForums The original o-ring and backer are still in place. There must be an imperfection in the surfaces that are causing this to start leaking again.
I moved it to both extremes and deadheaded the pressure a couple of times and it remained dry so hopefully it will hold.
Is it possible with all the pipe wrench marks laterally across the gland, that there are stubbie sticking up causing the gap seal to be excessive? I realize the oring and backer are to seal on the insides of the cylinder but maybe the are in a bad spot or not going in far enough. I think that’s a great idea with the silicone. Is there any way to drill and tap a small machine screw into the threads near the end like Case machines, to keep the gland tight? Might be the easiest but be careful and only drill through hole and just start, then tap size drill, and tap. People trying to drill through 2 layers generally end up breaking the drill bit.
Anything is possible. This silicone is pretty good stuff so I don't expect the gland to come loose. That hasn't been it's problem anyway. Every time I have had to loosen it it has been a battle.