frantically relaxing
Senior Chief Petty Officer
- Joined
- Nov 19, 2011
- Messages
- 699
At the end of the 2011 season, my trim pump stopped working. I pulled it out, checked it out and fixed it.
Last weekend it quit working again! This time I checked it out a little harder
... Boat is a 2003 Chaparral 260 SSi, 8.1Gx Volvo DP--
Pics are from the first fix, but not much changed. Once the pump bracket is unscrewed from the floor, the 2 long bolts running thru the motor is all that holds the motor to the pump housing. Beware, as these same screws also hold the motor together, it will come apart as you pull it off if you're not careful! It looked (and still looks) almost like new...
With the end cap off, the brushes look barely worn (still)...
The thermal overload points looked fine. (ahh, but looks are deceiving)
The commutator had plenty of carbon scoring---
---which I cleaned up with a little emery cloth...
=================
I also ran the emery cloth across the contact points of the thermal switch. The pump ran flawlessly until last Saturday.
When I pulled the motor apart, it looked almost identical to how it went back together. Commutator was still clean, brushes still look like new, points still looked fine.
LOOKED fine.
I lightly sanded the commutator again, and ran the emery cloth thru the points again. All looked like new. I was ready to re-assemble it, then I thought, maybe I should grab the Fluke and do some testing...
Short version-- even after sanding the points (again), my meter showed NO continuity between the 2 sides of the points! So I propped open the points and took a razor blade to the contacts. Some white crusty's came off, not a ton, but it must've been enough to prevent the points from contacting. Afterwards, continuity! I gave the points another scraping for good measure, then re-assembled the pump, certain that it would again work like new...
And it did! I then re-attached the pump assembly to the floor, installed the captain's call exhaust pipe, re-attached the extinguisher, re-installed the battery, and called it a good day--
Right up until I found out yet another thing the hard way... While the pump ran perfectly, it was running BACKWARDS!
Up lowered the drive, down raised the drive--
The motor case was 180? out of phase, so the magnets were reversed... Guess I got lucky the first time! SO, if you ever take apart an electric motor that runs both directions, be sure to note which way the case was!
Hope this might help a few of ya!
Last weekend it quit working again! This time I checked it out a little harder
... Boat is a 2003 Chaparral 260 SSi, 8.1Gx Volvo DP-- Pics are from the first fix, but not much changed. Once the pump bracket is unscrewed from the floor, the 2 long bolts running thru the motor is all that holds the motor to the pump housing. Beware, as these same screws also hold the motor together, it will come apart as you pull it off if you're not careful! It looked (and still looks) almost like new...
With the end cap off, the brushes look barely worn (still)...
The thermal overload points looked fine. (ahh, but looks are deceiving)
The commutator had plenty of carbon scoring---
---which I cleaned up with a little emery cloth...
=================
I also ran the emery cloth across the contact points of the thermal switch. The pump ran flawlessly until last Saturday.
When I pulled the motor apart, it looked almost identical to how it went back together. Commutator was still clean, brushes still look like new, points still looked fine.
LOOKED fine.
I lightly sanded the commutator again, and ran the emery cloth thru the points again. All looked like new. I was ready to re-assemble it, then I thought, maybe I should grab the Fluke and do some testing...
Short version-- even after sanding the points (again), my meter showed NO continuity between the 2 sides of the points! So I propped open the points and took a razor blade to the contacts. Some white crusty's came off, not a ton, but it must've been enough to prevent the points from contacting. Afterwards, continuity! I gave the points another scraping for good measure, then re-assembled the pump, certain that it would again work like new...
And it did! I then re-attached the pump assembly to the floor, installed the captain's call exhaust pipe, re-attached the extinguisher, re-installed the battery, and called it a good day--
Right up until I found out yet another thing the hard way... While the pump ran perfectly, it was running BACKWARDS!
Up lowered the drive, down raised the drive--
The motor case was 180? out of phase, so the magnets were reversed... Guess I got lucky the first time! SO, if you ever take apart an electric motor that runs both directions, be sure to note which way the case was!
Hope this might help a few of ya!