Interesting topic, I can’t recall if I installed that cap last time I did ours. Going to need to check it out before the season gets going!
Official Caterpillar3116/3126 Thread
- Thread starter carterchapman
- Start date
Michael Striplin
New Member
I highly doubt the shafts need replacing as they really don’t wear. I rebuilt mine and it was simple and inexpensive. Mine were dripping at the shaft before and are working great now.
- Aug 20, 2021
- 1,312
- Boat Info
- Started out as MAYBE A DANCER
Became a Dancer - 12/23/21
- Engines
- 450 DA Sundancer running CAT 3126
Does anyone have a PILOT LIGHT on the Glendenning synchronizer?
My 1996 450DA does not have one, so we go with the GUT, easy enough.
Anyone?
BUELLER ?
BEST !
RWS
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www.glendinningprods.com
My 1996 450DA does not have one, so we go with the GUT, easy enough.
Anyone?
BUELLER ?
BEST !
RWS
- Jun 5, 2016
- 5,590
- Boat Info
- 410 Sundancer
2001
12" Axiom and 9" Axiom+ MFD
- Engines
- Cat 3126 V-Drives
No pilot light on the glendinning on minexand I've severcseen that option on a sea ray. But if I were to add one, I'd probably add wiring and pilot lights for the CAT air heaters while I was at it.
Mine didn't, but I added one. Used a micro-led bulb, drilled a hole and mounted it directly below the sync gauge. Instructions for wiring are in the manual. Very easy to do
- Jun 5, 2016
- 5,590
- Boat Info
- 410 Sundancer
2001
12" Axiom and 9" Axiom+ MFD
- Engines
- Cat 3126 V-Drives
The minor rebuild kits (basically the seal, wear plate and impeller) are pretty reasonable if you have a shop press to do the job.
- Jun 5, 2016
- 5,590
- Boat Info
- 410 Sundancer
2001
12" Axiom and 9" Axiom+ MFD
- Engines
- Cat 3126 V-Drives
I'd love to have the engage/disengage switch in the throttle lever under my thumb to make it one handed operation.
Thought about putting a microswitch on the side of the port throttle lever knob. Had the lever been hollow rather than solid, fishing wires up would have been easy..Alas, its solid.
Had a failed coolant reservoir cap on my Stbd 3116TA, which when tested doesn't hold pressure, so ordered a new one.
Received a 7psi cap with no rubber seal (where the cap mates with the tank filler neck).
New cap leaks coolant when the engine reaches temp...well because the engine has seen a few leagues and at some point the top of the tank filler neck bent very slightly becoming uneven. Not a problem for the old cap, which has the rubber insert because the rubber plus downward pressure of the cap when tightened effectively sealed off the uneven top surface of the tank filler neck.
Q: Has the 3116TA reservoir cap been replaced with this 7psi (pos) or is there a 13psi cap with the rubber insert that can still be ordered from Cat?
Anyway I also levelled off the top of the tank filler neck, as it was really just an outer edge that had lifted slightly. I swapped the port (13psi) cap and new stbd (7psi) cap and no more leaks at idle running temp (from either engine). My concern is that at 2300 rpm that 7psi cap without the rubber ain't going to cut it because the metal to metal mating won't be water tight unless both surfaces are perfectly level. Makes me nervous.
You might say the pressure valve will release at a low 7psi and overflow to the overflow tank, but it didn't on the stbd side...coolant just started coming out from under the cap.
Thoughts?
Received a 7psi cap with no rubber seal (where the cap mates with the tank filler neck).
New cap leaks coolant when the engine reaches temp...well because the engine has seen a few leagues and at some point the top of the tank filler neck bent very slightly becoming uneven. Not a problem for the old cap, which has the rubber insert because the rubber plus downward pressure of the cap when tightened effectively sealed off the uneven top surface of the tank filler neck.
Q: Has the 3116TA reservoir cap been replaced with this 7psi (pos) or is there a 13psi cap with the rubber insert that can still be ordered from Cat?
Anyway I also levelled off the top of the tank filler neck, as it was really just an outer edge that had lifted slightly. I swapped the port (13psi) cap and new stbd (7psi) cap and no more leaks at idle running temp (from either engine). My concern is that at 2300 rpm that 7psi cap without the rubber ain't going to cut it because the metal to metal mating won't be water tight unless both surfaces are perfectly level. Makes me nervous.
You might say the pressure valve will release at a low 7psi and overflow to the overflow tank, but it didn't on the stbd side...coolant just started coming out from under the cap.
Thoughts?
- Aug 20, 2021
- 1,312
- Boat Info
- Started out as MAYBE A DANCER
Became a Dancer - 12/23/21
- Engines
- 450 DA Sundancer running CAT 3126
I'd get the correct PSI cap with the rubber base for BOTH engines.
Replaced mine during the RETURN TO BASELINE project.
Next up are the nearly 30 year old transmission cooler hoses...
BEST !
RWS
Replaced mine during the RETURN TO BASELINE project.
Next up are the nearly 30 year old transmission cooler hoses...
BEST !
RWS
Three functions to the coolant reservoir fill cap. One is to maintain system pressurization to prevent coolant boiling, another to allow for coolant expansion as it gets hot to vent to the overflow bottle, and a third to allow coolant to be drawn back into the engine's coolant system from the overflow bottle when things cool down and the coolant contracts.
Three seals are required on the cap to do this - one between the cap and outer part of the filler neck, one between the cap and inner part of the filler neck, and one on the recovery disc/valve. Usually the seal for the recovery disc is the same seal for the inner part of the filler neck. Two of those seals are spring loaded and one is an interference fit.
So, yes that outer neck must have a seal in the cap.
- Aug 20, 2021
- 1,312
- Boat Info
- Started out as MAYBE A DANCER
Became a Dancer - 12/23/21
- Engines
- 450 DA Sundancer running CAT 3126
IMPORTANT PREVENTATIVE MAINTENANCE TIP:
Check the two ring terminals on the engine mounted fuel solenoid.
STRONGLY SUGGEST removal and cleaning all contact points and protecting with dielectric grease.
On the way home from the yard after getting a new bottom job, i clicked on the Glendenning to get on plane and lost the port engine.
Wouldn't start or run.
Dropped anchor in the harbor.
Racor gauges looked fine - no restrictions shown.
Did all the usual checks, then popped in another Bosch ice cube relay.
Still no joy.
Came home on one engine. (proud of my skill in negotiating the split/curved bridge)
Re-checked the primer pump valve (closed) and stroke pump for tightness.
Decided to try to prime the engine with the CAT primer pump.
Engine fired right up and ran fine.
BUT WHAT CAUSED THE ENGINE TO LOOSE FUEL???
FW diagnosed the problem in 10 minutes !
While not as loose as the one arching (described earlier in this thread by Cap Ray Bock) it was kinda snug, but not dead ass tight.
Took care of the starboard side as well - found that side to be less than tight.
Consider those wires are likely 14 or 12 gauge - lots of amperage needed to operate that solenoid.
Go clean yours before your next outing. This can and will happen without any warning.
BEST !
RWS
- Jun 5, 2016
- 5,590
- Boat Info
- 410 Sundancer
2001
12" Axiom and 9" Axiom+ MFD
- Engines
- Cat 3126 V-Drives
There is a 13 or 14 psi cap…you received the wrong part. I replace when I replace the ELC along with the thermostats.
- Oct 6, 2006
- 12,155
- Boat Info
- 1996 450DA
- Engines
- 3116 Caterpillars
Well, I ain't Bueller, but here is my red-neck opinion on the pilot light question.
1. If you operate the Glendinning as instructed, and advance the stbd throttle to the wot stop right after you energize the Glendinning sync control with the Sync switch to remove the cable load from Gelndinning control box, it was always easy for me to just glance at the throttles and identify where the stbd throttle was positioned compared to the port one that is operating both engines at this point.
2. I occasionally run a couple of large convertibles for friends …….on is a 54 Hatteras the other is a 55 Viking. The Viking has Mathers electronic throttle controls and the Hat has turn of the century manual controls and a synchronizer that only works sometimes….maybe. The Viking is confusing as all get out because the throttle controls have as many little red pilot lights as a Christmas tree. I sometimes catch myself turning the synchronizer off just to see which red light goes out. Give me a Sundancer with Cat's and a Glendinning synchronizer any day over either of these boats.
Frank
Any issues with leaving dye in the coolant? Lucky me I have slow coolant leak in the worst possible place, the Stbd side of the Stbd engine. Had to remove the exhaust elbow and hose just to be able to see the Stbd side. Pressurized they cooling system, but still can't find the leak as its a ery slow but steady leak. The coolant makes its way to the center of the underside of the oil pan and drips down from there. Next step is dye and UV light.
- Jun 2, 2008
- 5,024
- Boat Info
- 1998 450 Sundancer, Achilles dinghy w/15hp
- Engines
- 3126 Cat's
I had a pinhole leak in the port coolant tank that only dripped at running temp, but that was an easy one.
Cat potentially makes a coolant dye, so I'd check with them.
I see the coolant regulator junction box as the highest potential for leaks given it's a universal joining point for so many different hoses plus it has a metal to metal mating surface requiring a gasket in the most impossible place (at least on the 3116).
@Chris L , also are you sure there is an external leak? Coolant might be burning off, or entering the "oil stream", if there is an internal gasket fault or (worst case) crack in the head.
I see the coolant regulator junction box as the highest potential for leaks given it's a universal joining point for so many different hoses plus it has a metal to metal mating surface requiring a gasket in the most impossible place (at least on the 3116).
@Chris L , also are you sure there is an external leak? Coolant might be burning off, or entering the "oil stream", if there is an internal gasket fault or (worst case) crack in the head.
Leak was discovered late in the season in 2023 about a month before winter layup. Oil was changed during layup and Blackstone analysis done. Came back clean as a whistle. Just getting to it now as work kicked my ass last fall, and couldn't get a day off to catch my breath.
Degreased and cleaned the crap out of the engine last week before pressurizing the cooling system, but couldn't find the leak. One week later there was coolant dripping from the center of the oil pan into the bilge. Not a lot but still a measureable quantity. Its a slow leak. The dye will do the trick..
Not an answer to the dye but my leak appeared to be coming from the same side. Turns out it was actually coming from the tiny hose that joins the water pump up to the expansion tank (I think that’s where the connection goes)
Ifs located behind the airsep and was as simple as tightening the clamps.
Ifs located behind the airsep and was as simple as tightening the clamps.
Thanks. Since that side is so hard to access and I've already yanked the exhaust hose, might as well replace all the hoses/clamps. Ordered new hoses and constant tension clamps.
