Charlie; You are essentially correct in assuming that an hydraulics shop can source the needed parts even though Navtec or other back stay adjuster maker no longer supply a kit.
After nearly 40 years experience in the construction machinery and forklift industry, I can confidently say that most any hydraulics shop (or industrial equipment dealer) has the skill set and tools for the job. But they will probably need to identify and source the various wear parts and seals in the pump and cylinder. After all, they normally work on hydraulic cylinders that are designed for 10,000 to 40 or 50,000 PSI pressures and are a lot larger in diameter that what is used on a boat. All hydraulic cylinders leak, even brand new ones. Initially it is very slow leakage primarily around the seal between the piston and the cylinder wall resulting from the pressure differential between the top and bottom of the piston. As the seal wears the leakage gets higher over time. Best to relieve the pressure on your back stay adjuster when you get off the boat. If you leave the adjuster at, say 2000 pounds, and come back two weeks later and see 1500 or 1000 I would not be too worried. One week and dropped to near zero would probably indicate a need for service. The most likely source for wear is environmental contamination coming in through the seal around the piston shaft connected to your backstay, as has already been pointed out. The suggestion to keep the rod clean and maybe put a felt ring around the top of the cylinder as a wiper is a good one to catch the potential contamination and fine dust particles that can cause wear. As the shaft seal wears and lets contamination into the cylinder, you get increased wear on the piston seal and increasing internal pressure leakage over time. I'm not sure that temperatures will have much effect on the life of seals and o-rings. Although I can see that sub zero temperatures could cause some thermal contraction that would exacerbate any small leakage that might already exist when the piston is left under pressure. As far as high temperatures, we're not talking about hundreds of degrees that will destroy the seals, and I wouldn't expect the seals to soften enough to be damaged by friction, but I high temps from southern suns would accelerate the aging of the material to some degree. But one the whole, Charlie, I would guess that 15 years between rebuilds of your adjuster would be pretty normal. Rick Brass Imzadi C&C 38 mk2 (with an old-style mechanical back stay adjuster using a winch handle) Washington, NC -----Original Message----- From: Stus-List <cnc-list@cnc-list.com> Sent: Nov 17, 2023 7:14 PM To: Stus-List <cnc-list@cnc-list.com> Cc: cenel...@aol.com <cenel...@aol.com> Subject: Stus-List Re: Recommendations to rebuild hydraulic cylinders for backstay 96For the 2nd time in its 30 yr life, I left my Navtec cylinder with the local hydraulic shop for a rebuild. Unfortunately it’s so old that complete rebuild kits are not available but he is replacing what he can with what is available re seals, etc. Since it is basically a manual pump and assuming no scoring or other damage to the metal parts, I think that any disposable parts are either seals or ‘0-rings’ which are likely available in the appropriate sizes and diameters individually from McMaster-Carr. My thought is to tell him to source the individual items and build a rebuild kit himself. OTOH, I have never seen the inside of any hydraulic pump! Am I oversimplifying this or is the hydraulic shop just doing the ‘rebuild’ with what parts of the rebuild are easily and relatively cheaply available to keep the rebuild simple without disassembling and sourcing the parts that would likely be part of a complete rebuild kit? Charlie Nelson Water Phantom 1995 C&C 36 XL/kcb Sent from the all new AOL app for iOS (Sent from the all new AOL app for iOS) On Friday, November 17, 2023, 6:27 PM, David Risch via CnC-List <cnc-list@cnc-list.com> wrote: Just go to a local hydraulic shop. Sorry as a Navtech “technician” ripped me off for two “re-builds” in two years at $500 an incompetent rebuild. Construction guys don’t tolerate that crap. $100 once and done. It is just a pump. From: Matthew L. Wolford via CnC-List <cnc-list@cnc-list.com> Sent: Friday, November 17, 2023 2:12 PMTo: Stus-List <cnc-list@cnc-list.com>Cc: Matthew L. Wolford <wolf...@erie.net>Subject: Stus-List Re: Recommendations to rebuild hydraulic cylinders for backstay I also like Lew, whom I contacted based on recommendations from this list. That said, he’s not from NJ (far from it), and shipping cost almost as much as the work. Also, the rebuild work I had done was prophylactic, and my unit now has a very minor leak that it didn’t have before. I’m sure he’d fix it if I sent it back. Bottom line: as much as I like Lew, I suggest finding someone local. Sent from my iPhone On Nov 17, 2023, at 1:37 PM, Dennis C. via CnC-List <cnc-list@cnc-list.com (mailto:cnc-list@cnc-list.com)> wrote: Second Lew Townsend. He rebuilt mine after another Navtec rebuilder botched it. Excellent to work with. -- Dennis C. Touche' 35-1 #83 Mandeville, LA On Fri, Nov 17, 2023 at 8:55 AM ALAN BERGEN via CnC-List <cnc-list@cnc-list.com (mailto:cnc-list@cnc-list.com)> wrote: Lew Townsend did all my Navtec hydraulic repairs. Don't know whether he does Sailtec, but you can call him at (206) 498-7282. He does quality work. Others on the list have also used him. Alan Bergen 35 Mk III Thirsty Rose City YC Portland, OR On Fri, Nov 17, 2023 at 6:36 AM Allen Miles via CnC-List <cnc-list@cnc-list.com (mailto:cnc-list@cnc-list.com)> wrote: Good morning All, Septima has moved from Hampton Roads, VA to Bayville, NJ. Upon arrival we noticed that the hydraulic cylinders for the backstay were leaking. Does anyone have recommendations on a reputable service to rebuild them in the NJ area? They are Sailtec branded. However, the marina we are in refuses to do business with them based on previous bad experiences. Love to support local businesses but also want a quality job. Any suggestions appreciated. Thanks and have a great weekend, Allen Miles 30 Mk II, Septima Bayville, NJ Please show your appreciation for this list and the Photo Album site and help me pay the associated bills. Make a contribution at:https://urldefense.com/v3/__https://www.paypal.me/stumurray__;!!LIr3w8kk_Xxm!qs2Qvcff0x2r9Xu484Io53CdPY1cNhT0tOLx9hjHxOpx03avqPpvzczr7rQ5cI-zSB2xudbFXoqRejPEBjRfjcI$ Thanks for your help.Stu Please show your appreciation for this list and the Photo Album site and help me pay the associated bills. Make a contribution at:https://www.paypal.me/stumurrayThanks for your help.Stu Please show your appreciation for this list and the Photo Album site and help me pay the associated bills. Make a contribution at:https://www.paypal.me/stumurrayThanks for your help.Stu Please show your appreciation for this list and the Photo Album site and help me pay the associated bills. Make a contribution at:https://www.paypal.me/stumurrayThanks for your help.Stu
Please show your appreciation for this list and the Photo Album site and help me pay the associated bills. Make a contribution at: https://www.paypal.me/stumurray Thanks for your help. Stu
