Reply
 
Thread Tools Search this Thread Display Modes
 
Old 05-22-2022, 02:42 PM   #1
Newbie
 
City: Deale, MD
Vessel Name: Lasata
Vessel Model: Grand Banks 49CL
Join Date: Apr 2014
Posts: 2
Autopilot Problem

Hello all. I own a 1997 Grand Banks 49 CL. About 2 years ago, we replaced the original Raymarine autopilot with a Garmin Reactor retrofit unit. We did not replace the Raymarine autopilot pump. In Spring 2021, we found the AP pump and the steering cylinder were leaking (this may have predated the AP upgrade). We installed a new Octopus OCTAFG1612 AP gear pump and a new Teleflex HC5379 steering cylinder. The autopilot worked great for about 2 months of weekend use at which point it started squealing and leaking fluid. Octopus replaced the AP pump under warranty. After about another 2 months of flawless performance, the replacement AP pump also started squealing. After consulting with Octopus and with Garmin, we replaced the gear pump with an Octopus 2012 reversing piston pump.

The AP has never functioned properly with the piston pump. The AP will hold a course for about 30 seconds and then drifts at an increasing rate either to port or starboard. If we nudge the wheel, the AP will return to the original course, but immediately begins to drift off course again. The Garmin AP electronics have never thrown an error code. Replacing the Garmin ECU and CCU did not solve the problem. We suspected a blockage in at least one of the upper or lower station Capilano helm pumps and sent both to Seastar for rebuilding. Seastar found and repaired a blocked valve in the upper station pump. Both helm pumps were reinstalled.

The problem continued, so we installed pressure gauges on the port and starboard connections of the AP pump. Those gauges show about 200 psi in both legs as soon as the AP is engaged. This suggests that there is still a blockage somewhere in the system, but I have no idea where. When steering manually, the active leg shows about 200 psi, but the inactive leg shows atmospheric pressure.

Sorry for the lengthy history. Does anyone have a suggestion about possible causes or solutions?

Thanks,
Bill
wstrauss is offline   Reply With Quote
Old 05-22-2022, 04:41 PM   #2
Guru
 
hmason's Avatar
 
City: Stuart FL
Vessel Name: Lucky Lucky
Vessel Model: Pacific Mariner 65
Join Date: Aug 2013
Posts: 2,535
I had a 1996 GB. I also replaced the Raymarine autopilot with Garmin. I had nothing but problems until I replaced the pump with a Garmin pump. No problems after that. Good luck.
__________________
Howard
Lucky Lucky
Stuart, FL
hmason is offline   Reply With Quote
Old 05-22-2022, 04:55 PM   #3
Newbie
 
City: Deale, MD
Vessel Name: Lasata
Vessel Model: Grand Banks 49CL
Join Date: Apr 2014
Posts: 2
Thanks. Did you go with a standard Garmin autopilot pump or with the Smart pump?
wstrauss is offline   Reply With Quote
Old 05-22-2022, 04:58 PM   #4
Guru
 
hmason's Avatar
 
City: Stuart FL
Vessel Name: Lucky Lucky
Vessel Model: Pacific Mariner 65
Join Date: Aug 2013
Posts: 2,535
Sorry, it was awhile back and I’m not sure. My guess is the standard pump.
__________________
Howard
Lucky Lucky
Stuart, FL
hmason is offline   Reply With Quote
Old 05-22-2022, 07:38 PM   #5
Guru
 
rgano's Avatar
 
City: Southport, FL near Panama City
Vessel Name: FROLIC
Vessel Model: Mainship 30 Pilot II since 2015. GB-42 1986-2015. Former Unlimited Tonnage Master
Join Date: Oct 2007
Posts: 4,321
And by the by, welcome aboard, Bill.
__________________
Rich Gano
FROLIC (2005 MainShip 30 Pilot II)
Panama City area
rgano is offline   Reply With Quote
Old 05-22-2022, 07:50 PM   #6
Guru
 
syjos's Avatar


 
City: Gig Harbor
Vessel Name: Sandpiper
Vessel Model: Bluewater 40 Pilothouse Trawler
Join Date: Nov 2012
Posts: 2,280
The brand of autopilot and AP pump should makes no difference in operation.

An AP pump is a reversible hydraulic pump rated for a specific output to match rudder cylinder capacity and voltage. AP manufacturers do not build pumps and private label pumps purchased from pump manufacturers.

Rotary pumps are more efficient than piston pumps.

Ideally, an AP pump should be a variable displacement type that can be adjusted for an exact stop to stop rudder speed.
__________________
"My worst day working on the boat is still better than my best day at a job"
syjos is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Trawler Port Captains
Port Captains are TF volunteers who can serve as local guides or assist with local arrangements and information. Search below to locate Port Captains near your destination. To learn more about this program read here: TF Port Captain Program





All times are GMT -5. The time now is 05:45 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2022, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012