Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 14-03-2006, 08:58   #1
Registered User
 
markpj23's Avatar

Join Date: Nov 2005
Location: Black Hills, SD
Boat: Now Boatless
Posts: 1,148
Images: 47
Autohelm ST7000

The hydraulic pump on my ST7000 is not working. I get voltage to it, but it sounds as if a gear drive internal to the unit is stripped... makes noise but no pressure output.

All the manuals I've found for the ST7000 address the control heads & other electrical / electronic components. My guess is that the system works with a variety of hydraulic / linear drives, so my installation is unique - as would be others.

Picture of my unit:
http://cruisersforum.com/photopost/d...st7000-med.JPG
Has anyone on this forum dealt with the same setup?
__________________

__________________
Mark
markpj23 is offline   Reply With Quote
Old 14-03-2006, 11:23   #2
Registered User

Join Date: Jan 2005
Location: Seattle area (Bremerton)
Boat: C&C Landfall 39 center cockpit "Anahita"
Posts: 1,076
Images: 6
If you haven't already done so make sure that there is no air in the pump, that is the first and easiest check to make.

If you are mechanically adept you can disassemble the internal valves to discover if dirt has contaminated them (or any other part of the pumpset). So, cleaning and purging is the cheapest first thing that you can do before taking the entire thing away to have it serviced. If you are able to do it yourself you can identify the bearings and seals to buy them yourself from a bearing mart in your area. Otherwise you will pay many times the cost from the dealor. Most bearings and seals of that sized unit are only a few dollars apiece if universally available from a bearing mart.

Your PWM (pulse-width-modulated) drive unit operating with a small heading error delivers a "growling" noise that gets bad sounding if the valves are leaking and there is air in the pumpset and I wonder if that is the sound that you are hearing.
__________________

__________________
Rick is offline   Reply With Quote
Old 14-03-2006, 11:51   #3
Senior Cruiser
 
delmarrey's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Now in Blaine, WA
Boat: Modified Choate 40
Posts: 10,702
Images: 122
I concur with Rick.

Air will make pumps grawl. Actully, air can damage pumps. They cavitate and eat away the internal parts. Check the oil level and bleed out any air, if it has bleeders. You might even want to do an oil change. Moisture gets in there and can rust up parts or pit the bearings.

I work with hydrulics almost daily and it can be a blessing or a burden but is EZ to remedy..........................._/)
__________________
delmarrey is offline   Reply With Quote
Old 14-03-2006, 11:56   #4
Senior Cruiser
 
Alan Wheeler's Avatar

Cruisers Forum Supporter

Join Date: Dec 2003
Location: Marlborough Sounds. New Zealand
Boat: Hartley Tahitian 45ft. Leisure Lady
Posts: 8,038
Images: 102
These pumps are called a"positive displacement pump". Rick is quite right in his comments and so firstly follow his advice on checking for air. The valves are a little more difficult in this design. As you will have noticed, the pump and ram are part and parcel in this set up, and a little less than as straight forward as just a simple pump. However, the basic operation is the same on all of them. Just where the components are situated may differ.
First of all (assuming you have checked for Air first) if you have to strip it down, I suggest trying to get a parts break down.This will enaid you in knowing where springs, valves and seats are. Most of these pumps have little valves that use a ball bearing and a spring. There is nothing worse than to undo a cap and have a ballbearing and spring shoot over your right shoulder
As for how it all operates. The electric motor is the only part seperate to the pump itself. It is unlikely, but the drive at this point could have failed. The internals are a plate that is on an angle and oscillates as it rotates push the little pistons in and out. The pistons are nothing more than a hardened metal. They don't usually have any seals as such (although don't rule that out) and it is vertually impossible for them to fail. It is possible to have that yoke plate/piston to fail, but very rare.
Good luck and continue to ask questions if you need.
__________________
Wheels

For God so loved the world..........He didn't send a committee.
Alan Wheeler is offline   Reply With Quote
Old 09-05-2006, 10:27   #5
Senior Cruiser
 
DeepFrz's Avatar

Cruisers Forum Supporter

Join Date: Mar 2006
Location: Winnipeg
Boat: None at this time
Posts: 7,930
Mark, how did you make out with your noisy hydraulic pump?

Phil
__________________
DeepFrz is offline   Reply With Quote
Old 10-05-2006, 08:25   #6
Registered User
 
markpj23's Avatar

Join Date: Nov 2005
Location: Black Hills, SD
Boat: Now Boatless
Posts: 1,148
Images: 47
Other priorities got in the way. I hope to tear this one down by the end of the month. (not committing to which month here...)

Benefit of manual steering is that you really learn how she handles...
__________________
Mark
markpj23 is offline   Reply With Quote
Old 14-05-2006, 07:36   #7
Senior Cruiser

Join Date: Apr 2006
Posts: 2,453
As an aside - Mark? How DOES your E52 handle? Is it ketch rigged? I have been using the ST6000 series in mine and it has done well. Only regret is that I didn't get the upgraded 'brain' (not mine, the autopilot). The boat had the 6000 series installed, but (of course) it didn't work so had to replace the computer, sensors, and control head(s) - the drive unit was fine, and worked with the new system.
__________________
S/V Elusive is offline   Reply With Quote
Old 15-05-2006, 08:21   #8
Senior Cruiser
 
Talbot's Avatar

Cruisers Forum Supporter

Join Date: Jun 2004
Location: Brighton, UK
Boat: Privilege 37
Posts: 3,579
Images: 32
if you have the upgraded brain fitted, it may be possible to get the rate gyro added as an extra. worth contacting raymarine to investigate, as it makes a big difference.
__________________
"Be wary of strong drink. It can make you shoot at tax collectors - and miss."
Robert A Heinlein
Talbot is offline   Reply With Quote
Old 15-05-2006, 09:46   #9
Moderator Emeritus
 
GordMay's Avatar

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 31,580
Images: 240
Maggie wants to know where I could get an “upgraded brain” fitted, how much the surgery costs, and how long my post-surgical recovery might take?
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 15-05-2006, 10:05   #10
Senior Cruiser
 
Talbot's Avatar

Cruisers Forum Supporter

Join Date: Jun 2004
Location: Brighton, UK
Boat: Privilege 37
Posts: 3,579
Images: 32
LOL!
__________________
"Be wary of strong drink. It can make you shoot at tax collectors - and miss."
Robert A Heinlein
Talbot is offline   Reply With Quote
Old 16-07-2006, 18:55   #11
Registered User
 
markpj23's Avatar

Join Date: Nov 2005
Location: Black Hills, SD
Boat: Now Boatless
Posts: 1,148
Images: 47
Well today I bled the hydraulic ram and found no air lock or bubbles. The brain tries to drive the rudder but the darn pump sounds like there's a broken gear inside it or something. I'm afraid this one will take lots more time to resolve

First to remove the ram from the quadrant - gee that should be fun...
__________________
Mark
markpj23 is offline   Reply With Quote
Old 09-05-2007, 09:19   #12
Senior Cruiser
 
DeepFrz's Avatar

Cruisers Forum Supporter

Join Date: Mar 2006
Location: Winnipeg
Boat: None at this time
Posts: 7,930
Hi Mark, I was just wondering if you ever got your autopilot fixed?
__________________
The Blue Dot Campaign. This Changes Everything.
DeepFrz is offline   Reply With Quote
Old 09-05-2007, 09:55   #13
Registered User
 
markpj23's Avatar

Join Date: Nov 2005
Location: Black Hills, SD
Boat: Now Boatless
Posts: 1,148
Images: 47
Quote:
Originally Posted by DeepFrz
Hi Mark, I was just wondering if you ever got your autopilot fixed?
Not yet unfortunately... 3 head rebuilds (on a 2-head boat no less) and a FWD A/C replacement have consumed my time thus far. And we actually plan to go SAILING for the next 2 days!!

I hope to get this autopilot ripped out saturday morning and take it home with me for repair. But I'll be darned if we didn't just discover that the genset exhaust hose has rotted through near the outlet fitting and is leaking fumes into the boat.... sigh....
__________________
Mark
markpj23 is offline   Reply With Quote
Old 09-05-2008, 06:58   #14
Registered User
 
markpj23's Avatar

Join Date: Nov 2005
Location: Black Hills, SD
Boat: Now Boatless
Posts: 1,148
Images: 47
Check the Simple Things First!!

Well.... mystery solved! I pulled the whole ram assembly, took the hydraulic vane pump cover off - no issues seen at all. Hmmm......

So off to a local hydraulics repair shop. Turns out the issue was electrical.... one of the motor brush springs had broken and there was arcing across the brush. A quickly fabricated replacement and armature clean-up had me back up in no time.

Since I'm less comfortable with hydraulics than I am with electrical.... I of course assumed the worst and started checking hydraulics first.

Will be a much nicer transit to FL now that we won't be hand-steering the whole way.

__________________
Mark
markpj23 is offline   Reply With Quote
Old 03-06-2008, 05:55   #15
Registered User

Join Date: Jun 2008
Posts: 10
ST7000 problem

I am having what seems to be the worst kind of problem......intermittent failure.

Yesterday I activated the autopilot and as soon as it made its first correction it never came out of the turn.....

After several tries it kept doing the same thing. Heading indicated 113 and activating the AUTO button it turned the rudder to get back on course, but never came out of the rudder change.

After a few hours, still on the same general heading, the heading indicator showed 130, so I tried the AUTO button again and.....it worked and kept on working fine for the rest of the day.

It almost seems like something in the electronic heading sensor got stuck, but as far as I know, the heading sensor has no moving parts.

I welcome comments form experienced users that might be able to suggest a solution for me, as I will be no place that I can get competent service for the next few months, and I dread the idea of manual steering on long passages. If necessary, I can get replacement parts by FedEx.

Thanx for the prompt support.
__________________

__________________
yachtsman44 is offline   Reply With Quote
Reply

Tags
autohelm

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Autohelm 5000 Quincofish Marine Electronics 2 16-04-2003 22:59



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 00:06.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.