B&G T1 Hydraulic Ram Repair

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Article originally written by Steve Johnson

On the way home from Mexico our B&G T1 electro hydraulic ram lost its fluid.  Fortunately, Scott Ligon posted several Mantatech entries from the archives on this subject.  That was a big help.

A local hydraulics shop replaced the ram’s seals for $160.  It was a straight forward job for them.

B&G’s website has a document called “Type T1 and T2 Hydraulic Ram ‘Bleeding’ ” procedure in the FAQ area of their website.  This procedure calls for an ISO 10 fluid like Q8 Dynobear 10.  Q8 Dynobear 10 is a 10 centistokes slideway lubricant that’s not available in the US.  Castrol Tech Support suggested three ISO 10 substitutes:

  • Castrol Hyspin Spindle Oil 10
  • Texaco Spindura 10
  • ExxonMobil Velocite No. 6.

Grainger stocks the ExxonMobil in gallon containers for about $25.

The B&G procedure calls for a kit of two special tools.  Neither Wheelhouse nor Navico New Hampshire knew about this kit but Navico UK said to order CP_1043 Ram Bleeding Kit for $247 RRP.

Rather than buying these tools I created an equivalent kit for about $40 from hardware and auto parts stores.  See the photo below.


The T1’s blue filler plug has a 13 mm diameter x 1.5 mm thread pitch, a very rare thread type.  After a long Internet search for “M13-1.5”, a readily available part was found, a dual brake master cylinder adapter.  Four manufacturers’ part numbers were found:

  1. AGS BLF-34C. AGS/M13 – 1.5 bubble male to 3/8 in. – 24 inverted female port domestic brass brake adapter for 3/16 in. line
  2. Edelmann 263000
  3. Weatherhead 7972
  4. Dorman 327858

Advance stocks item #4 which turned out to have improper threads.  AutoZone stocks item #1.  Their AGS part worked well.  The threaded portion of the adapter needs to be shorted to a depth similar to the filler plug.  A sanding machine worked well.  The through hole was drilled larger for better flow.

A quarter turn ball valve was used.  It’s only turned off once so even a gate valve could be used.  5/16” ID vinyl tubing was used.  The hydraulic fluid is oil so it’s easy on the vinyl.

Bleed the cylinder according to the B&G procedure.  Air bubbles tend to collect at the tip of the hose barb fitting on the downhill side of the valve.  Keeping the tubing vertical at that point helps keep the bubbles flowing up to the reservoir.  I stroked the cylinder for 2 to 3 hours before the bubbles stopped coming out.


The final step of the B&G procedure requires the removal of 20 cc of fluid.  Their kit has a graduated cylinder for this measurement.  I used the vinyl tubing.  20 cc is 4 teaspoons.  By experiment, that’s 7 inches of height in 5/16” ID tubing.

The B&G procedure says to insure there is at least 50 cc of fluid available.  Mark the starting level of fluid in the tube with a Sharpie and mark the 20 cc line which is 7 inches above that.  When the cylinder is stroked and the valve is opened, just about 50 cc is drawn in from the tubing about 18 inches in 5/16” ID tubing.  You then force out the same amount that was drawn in plus 20 cc more.  See the starting mark and starting plus 20 cc mark on the photo below.


Brush Replacement

I bought replacement brushes from Navico for $50 + shipping rather than Myles Marine Electronics who sells them for $80.  Both prices are excessive.  To replace the brushes, remove the motor’s bolts and remove the end cover and the case together.  Inside the end cover there’s a nylon disc that’s used for insulation.  Mark the rotational position of the nylon insulating disk with respect to end cover so you can put it back in the right position.  Watch for the wavy washer that’s in the end cover.

Cut off the old brush leads, leaving enough of a tail to be soldered to the new brush leads.  Install the new brushes and solder the leads to remnants of the old brush leads.  Route the brush leads so they won’t contact the case.  There is some room to route them axially but not so much radially.  Reassemble the case and end cover over the armature.  Reinstall the nylon disc and the wavy washer in the end cover.  Install the bolts.