Bennet trim Tabs

visionary1

Cadet
Joined
May 18, 2010
Messages
7
I have a 1974 chris craft Catalina 251. I just bought this particular boat as I just sold my thompson. My issue that I am having is every thing on the boat works except the trim tabs. I noticed that the fluid resovoir was empty so I filled it according to the instructions Approx 22 oz. atf fluid. When i push the button bow up/bow down I don't here anything coming from the motor on the trim pump but I do see that my voltage drops. the fuse looks fine and there is power to the unit not sure why they won't go up and down. Is there supposed to be a definate sound from the pump motor when it is pumping fluid? I am not sure the pump is working.
 

dazk14

Ensign
Joined
Jul 22, 2008
Messages
966
Re: Bennet trim Tabs

yes, the pumps make some noise when pumping. If you're sure 12v is getting to the pump, next check for good ground.
Since your voltmeter is dropping there's a good chance the pump is shot.
Call Bennett directly, they have excellent customer service.
 

Boatist

Rear Admiral
Joined
Apr 22, 2002
Messages
4,552
Re: Bennet trim Tabs

You should be able to hear the pump if nothing running on the boat.
When you hit any switch two things should happend.
1: Pump starts in either foward or reverse.
2: You pick a solenoid for port or starboard tab. You can also pick both solenoids.

If your able to read diagrams and follow the trouble shooting the info below shoud give you all you need. Before you start make sure battery is fully charged as low voltage will cause the motor not to run and solenoids not to pick.
Good luck.


TRIM TAB SYSTEM SPECIFICATIONS

AND TROUBLESHOOTING GUIDE

Note: If additional technical information or troubleshooting assistance is needed, contact
Bennett Marine's Client Services Department at (954) 427-1400 or e-mail trimtabs@earthlink.net.

System Specifications

Trim tabs - Stainless steel

Actuators - Upper hinge material (part #A1103) made of flexible nylon. Remainder of actuator made of high impact fiberglass filled nylon.

Hydraulic Power Unit (HPU) - HPU draws a maximum 18 amps (broken-in) and operates on 12 volts DC (except 24 and 32 volt HPUs). Approximately 22 ounces of ANY TYPE AUTOMATIC TRANSMISSION FLUID (ATF) is required to fill the reservoir to proper level for single actuator installations. With the trim tabs fully retracted, proper fluid level is about 2" from the bottom of the reservoir.

The HPU forces both trim tabs full-up to full-down in 9-10 seconds, individually in 4-5 seconds. (Trim tab travel on dual actuator systems takes twice as long.)

Helm Control - Controls on 12 volt systems use 20 amp in-line fuse. (24 and 32 volt use proportionally smaller.)

Hydraulic Tubing - Tubing has 1/4" outside diameter and 1800 lb. burst pressure.

Wire harness - Wire colors and their functions:

Red wire Port solenoid valve
Green wire Starboard solenoid valve
Blue wire Motor forward (pump pressure)
Yellow wire Motor reverse (pump retract)
Black on HPU Ground
Orange on helm control Positive

Trim Tab System Diagram - Part number and descriptions in table below. Click to enlarge.




Diagram Number
Description
Part Number
1 Fluid reservoir VP1139
2 #10 x 1" screw H1180
3 Filler Stack --------
4 Filler Plug VP1140
5 Mounting bracket for HPU H1179
6 Lexan cover VP1138
7 Type 25 thread cutting screw VP1154
8 Motor strap VP1142
9 Solenoid valve VP1135-R
VP1135-G
10 Faceplate for HPU VP1144
11 1/8" pipe to 1/4" tube connector VP1146
12 Hex retainer VP1141
13 Nut with ferrule T1127
14 Hydraulic tubing (20' unless otherwise specified) H1171
15 Tube bending clip H1173
16 Female elbow H1172
17 Pipe nipple (3" unless otherwise specified) H1171
18 Upper hinge A1103
19 #14 x 1-1/2" screw H1174
20 Cylinder body A1105
21 Piston with o-ring A1109
22 Lower hinge pin A1115
23 Lower hinge A1113

25 Backing plate varies with size
27 Hinge plate varies with size
28 #10 x 1-1/4" screw EH1071
29 Trim tab only varies with size
30 1/4-20 x 3/4" machine screw H1175
31 Wire harness (22' unless otherwise specified) WH1000
32 Quick-disconnect plug VP1143
33 Nylon hanger H1177
34 Single lever control VC1000
35 20 amp fuse (12 volt system) H1176
36 Fuse holder H1178
37 Racing type control RT1000
38 Rocker switch control RS1000

Trim Tab System Information and Troubleshooting

Note: Click here for Bennett Trimdicator troubleshooting tips.

Bennett Trim Tabs are build to rigid quality standards. However, the marine environment is harsh. So, in the unlikely event a malfunction occurs, here is some helpful information.

1. If trim tabs do nothing...no movement...no sound from HPU -
- Inspect for blown 20 amp in-line fuse in helm control's orange wire.
- Inspect for disconnected or corroded connections on HPU ground wire, orange positive wire from helm control, and quick disconnect plug.

2. If HPU runs but trim tabs do not move -
- Inspect for disconnected or corroded red and green valve wire connections at helm control and quick-disconnect plug.
- The following test can be used to help isolate the malfunction.

Remove wires from helm control and touch together as follows:

Operation Reaction
Orange (+), blue, red Port trim tab down
Orange (+), blue, green Starboard trim tab down
Orange (+), blue, red, green Both trim tabs down
Orange (+), yellow, red Port trim tab up
Orange (+), yellow, green Starboard trim tab up
Orange (+), yellow, red, green Both trim tabs up

- If the tabs function properly in each of the above combinations, check the helm control. If during this test the trim tabs continue to malfunction, inspect the HPU.

3. If one trim tab operates and the other does not -
- Inspect for disconnected or corroded red or green valve wire connections at helm control and quick disconnect plug. (Red wire operates port trim tab; green wire operates starboard trim tab.)
- Reverse the hydraulic tubing at front of HPU to determine if malfunction is in HPU or actuator / hydraulic connections. If ,after reversing lines, the symptom shifts to other trim tab, a malfunction may exist in HPU. If the symptom remains on the same side, a malfunction may exist with the actuator / hydraulic connections.

4. If trim tabs go down but will not retract -
- Inspect for low voltage of the battery. Check battery voltage while HPU (or another accessory) is running. If voltage is less than 10 volts, valves will not open.
- Inspect for disconnected or corroded connections on helm control and at quick disconnect plug.

For additional assistance contact Bennett Marine's Client Services Department at (954) 427-1400 or e-mail trimtabs@earthlink.net.

Maintenance

- Periodically, check fluid level in HPU. With trim tabs fully retracted, fluid level should be about 2" from bottom of reservoir (approximately 22 ounces). To refill, remove the lexan cover and filler plug located on the front left hand corner of the reservoir. FILL WITH ANY TYPE OF AUTOMATIC TRANSMISSION FLUID (ATF) ONLY. Brands or types of ATF can be mixed. Running the HPU with excess or lack of fluid will not cause damage.

- Periodically, check for clean electrical connections on the back of the control, HPU ground wire and quick disconnect plug.

- Cold temperatures do not affect the trim tab system. No winterization is necessary.

- SALTWATER ONLY - To deter electrolysis, a zinc anode should be attached to the top of each trim tab. The zinc must make direct contact with the stainless steel. In the case of trim tabs installed on the boat as original equipment by the builder, a bonding system may be utilized for your particular model.

- We suggest using anti-fouling paint to help protect the trim tabs from marine growth. The secret to getting anti-fouling paint to adhere to your trim tabs is proper priming, and the best people to tell you what to do are the experts at the company that makes your anti-fouling paint. We strongly suggest that you contact the paint manufacturer and tell them you are painting "304 stainless steel" trim tabs, then follow their recommendations to the letter! Remember don't paint under the zincs.

- Unpainted trim tabs may acquire an orange discoloration. THIS OXIDATION OF SURFACE CARBON MOLECULES IS NORMAL. Orange coating can be cleaned off, but will eventually return. Note: this discoloration should not be confused with the pitting and corrosion of electrolysis.



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Bennett Marine
550 Jim Moran Boulevard
Deerfield Beach, Florida 33442 USA

Phone: 954-427-1400
Fax: 954-480-2897

E-Mail: trimtabs@earthlink.net
 

ovrrdrive

Petty Officer 1st Class
Joined
Apr 28, 2008
Messages
265
Re: Bennet trim Tabs

If that fails go on the Florida Sportsman forums and PM Tabman II or just post in the Bennett forum or even in General Boating. He works for Bennett and can help you out. Their customer support is great from what I've seen.
 

visionary1

Cadet
Joined
May 18, 2010
Messages
7
Re: Bennet trim Tabs

Thanks guys!! I am working directly with bennet now and they have been very kind so far. I have a couple of tests that they suggested that i run and tonight when i get some time I am going to do.

Thanks for the info.
 
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