My vacuum pump was not working on my 1989 340 Sea Ray. I was doing a visual inspection, checking connections, etc when the pump started working. I was tapping on the motor and moving wires around when it started working. Could it be that I need to replace the motor? Perhaps it was the pressure switch that activated when I was down there messing around.
intermittent VF vacuum pump
- Thread starter steeveau
- Start date
- Joined
- Feb 3, 2006
- RO Number
- 20150
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- 372
My best guess would be corrosion on the wires, or even up into the wires, especially since it started working when you moved them around. Mine isn't working on the same boat, so that's maybe tomorrow's project. VF's are very reliable, and pretty simple once I get my lard arse into that tiny SR engine room. Ok guys 'nuf said.
- Joined
- Sep 16, 2003
- RO Number
- 12212
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- 12,183
while it could be jsut yoru basic wiring issue (bad connector) or motor issue (especially if original), first thing to check is the Vac switch. It's on the vac tank, a basic push pull switch that sits at the top of a small rod with a spring. the switch rarely fails but the rod usually corrode inside the tank, or the washer inside breaks.
without touching any wire or motor, next time around try moving the rod in or out a little. you'll hear the swtich click on and off. If that doesn'tget the pump started then check connections near the motor. last, pull the motor and check brushes. try having it rebuilt by an alternator shop, it will be cheaper than replacing it. New motors are different, and much quieter, but come part of a $300 rebuild kit.
without touching any wire or motor, next time around try moving the rod in or out a little. you'll hear the swtich click on and off. If that doesn'tget the pump started then check connections near the motor. last, pull the motor and check brushes. try having it rebuilt by an alternator shop, it will be cheaper than replacing it. New motors are different, and much quieter, but come part of a $300 rebuild kit.
agree check the vacuum switch. after long periods of inactivity older switches contacts may get dirty. after a few forced cycles they seem to continue working. I dont remember if you can get at the contacts to clean them because I bought a new switch. of course the old one has been working fine ever since.
- Joined
- Sep 16, 2003
- RO Number
- 12212
- Messages
- 12,183
in my experience it's rarely the electgrical contact in the switch itself but usually the rod which links the diaphragm in the tank to the switch. wiggling it back and forth helps.
design may vary depending on vintage but at some point there was a plastic washer inside the tank on the diaphragm, with age that woudl become brittle and break. the newer versions have an SS washer inside.
it's pretty easy to see if the electric switch is causing the issue, just apply pressure against the spring and when it clicks see if the pump stops and starts everytime.
design may vary depending on vintage but at some point there was a plastic washer inside the tank on the diaphragm, with age that woudl become brittle and break. the newer versions have an SS washer inside.
it's pretty easy to see if the electric switch is causing the issue, just apply pressure against the spring and when it clicks see if the pump stops and starts everytime.
Thank you for the input. Looks like I've got some good direction when I get back to the marina this weekend. I look forward to having a boat with an engine room some day. Working on this 340 Sundancer with an aft cabin and V-Drives is tight for a six footer like me.