Visit our Popular Forums

john manning · 30-07-2021, 14:10

Its about 12 years since I last worked with marine hydraulic systems but my thoughts are :
If the helm pump works steering to port then the helm pump must be okay. If there were internal pump leaks they would normally be seen in either direction.
If there is nothing but helm and ram and hoses and the hoses are not leaking then the problem must be in the ram.
If the system was working normally before the ram seal was replaced then the only thing that has changed is the ram.
I assume that if the ram was removed to replace a leaking seal (which would have been a shaft seal) then all the ram seals would have been replaced (including piston seals). If the piston has a single bidirectional seal then it must be a bleeding issue. In this case you should feel some resistance to wheel movement once the ram is hard over. If the piston has two seals then one may be faulty.

NB The shuttle valve is usually mounted on the rear of helm pumps and allows the pump to operate in two directions. If changes the hoses from pressure hose to return hose and is controlled by the pump pressure applied to one side.

rainforest · 30-07-2021, 14:35

So ........ armed with everyone's input it is time to bleed the RAM again.
The fellow that changed the RAM seals is not available.
Problem is: when turning the wheel to STBD - the wheel does not come to a firm STOP. The wheel continues to creep.
Suggestion to fix it is to turn the wheel until the RAM has reached it's extreme travel and wheel continues to turn (no hard stop).
Then, while continuing to apply pressure to the RAM by continuing to turn the wheel
CRACK the connection to the STBD side of the RAM = to drain air & oil.
Then quickly tighten the connection
Suggestion is that this procedure may have to be done MANY times to get all the air out.
DOES THAT SOUND ABOUT RIGHT ??????

**skipperpete** · 30-07-2021, 14:57

That plan should work and it would work better if you flip the ram so that the connections are on the top side, not on the bottom as in your photo. It’s very important to maintain the helm pump oil level at all times. Be prepared for an unexpected level rise in the reservoir
If air gets compressed in the system but not vented...... that happens occasionally.

eggman · 04-08-2021, 03:40

Hello Rainforest,
I have a late 80s Wagner autopilot and occasionally take the auto pumpset out for service. I cap off the 3 lines to it. You may find that the hydraulic lines branch off between the helm pump and the pumpset. If so, your pumpset *bypass hose would be actually bypassing your ram and would be surprised that your rudder would work at all.*
Cheers, Gregg

rainforest · 28-08-2021, 16:38

Hi; In the unlikely event anyone is still following this marine blunder ... here is the status as of 28 August.
Same symptoms: Wheel stops when turning to port / but turning to starboard wheel continues to turn when RAM at full travel.
Suggestions, even by Paul Wagner, is that there is a problem in the helm pump.
The helm pump is the worst nightmare to get out of the binnacle.
So looked to eliminate possibilities by starting at easiest things to get to.
There are no bleeding fitting on the RAM.
A slim friend crawled into the 24-inch high compartment to crack the RAM's connection - while I turned the wheel to STBD = one tiny burp of air.
A week later a friend crawled in, removed the RAM from it's pins, tilted the stbd end UP and cracked the connection while I turned the wheel = maybe a tiny burp of air but same problem. Wheel still continued to turn beyond RAM all the way in. ???????????
SOOOOO (not easy) opened and terminated the plumbing coming from the helm PUMP = wheel now comes to a HARD STOP both ways. Could not turn the wheel in either direction.
Another SOOOOO ... removed the RAM, broke out crackers & cheese and a bottle of red AND sent the RAM to British Hydraulics. It is there as I type.
It is assumed there is a one direction internal seal leakage within the RAM cylinder. Be interesting to see what British Hydraulics has to say.
THANKS Skipper Pete and EVERYONE for your suggestions.

**skipperpete** · 28-08-2021, 19:23

Thanks for the update Rainforest, I admire your tenacity and your rapidly increasing knowledge of your hydraulic steering system.
I’m hoping for a positive outcome in the near future.

rainforest · 14-09-2021, 16:33

Finally (?) ......... THANK YOU everyone.
We opened and terminated both copper lines coming from the helm pump.
The result was that the wheel would not turn either way ....... so the only thing left was the RAM.
Removed the RAM (very difficult). Took it to a major hydraulics shop who gave it a $736.00 RE&RE. = chrome rod, hone & polish cylinder, test (likely buy lunch for the neighbourhood) and return to me.
We installed it back into the boat (an even more difficult job) a n d SUCCESS !!!
Broke out the crackers and cheese and a bottle of Red.
Still a couple bubble coming out BUT ....... hey, HAPPY MAN
AGAIN thanks everyone, SO MUCH, for your support.
So Ends This Day ...