Lost hydraulic drive

[spicemouse]

Hi again all,

 

You might remember me from post such as 

 

Well, as I was crusing yesterday afternoon I suddently lost drive. Nearly crashing into a moored up boat (some quick feet and bravery were required!).  The engine was running, but no forward or reverse at all. It's like the gearbox just gave up suddently. 

So far I've established that the cable from is still working, so it's not the controls. There is nothing round the prop and it turns freely. Nothing obvious on the gearbox, no leaks etc.. Pipes all look to still be holding the hydraulic oil, no bursts. 

 

What else could I be checking myself before I have to try and find someone who can have a look at it? 

Thanks! 

 

[spicemouse]

Today I've managed to get access to the hydraulic motor that drives the propshaft (or whatever it's called when it's only 12inces or so long), and the thing that attached is to said shaft. 
 

 

[Tony Brooks]

Make sure the oil reservoir is up to level (no oil = no drive) and then I would suspect the drive plate on the engine flywheel. Can't be 100% sure because something else just might have failed but those are the two things to check first.

1 minute ago, spicemouse said:

Today I've managed to get access to the hydraulic motor that drives the propshaft (or whatever it's called when it's only 12inces or so long), and the thing that attached is to said shaft. 
 

 

The key in the coupling does not look as if it is fitted properly. Try running it "in gear" to ensure the coupling is turning the shaft rather than spinning on the shaft. If the motor refuses to turn then back to the oil level then drive plate.

[spicemouse]

15 minutes ago, Tony Brooks said:

Make sure the oil reservoir is up to level (no oil = no drive) and then I would suspect the drive plate on the engine flywheel. Can't be 100% sure because something else just might have failed but those are the two things to check first.

 

The key in the coupling does not look as if it is fitted properly. Try running it "in gear" to ensure the coupling is turning the shaft rather than spinning on the shaft. If the motor refuses to turn then back to the oil level then drive plate.

in gear and nothing around the coupling moved. Better photo of it here:

 

It could be the hydraulic oil being depleted as I've only topped it up with about 100ml of what was left in a bottled marked "Hydraulic oil".  From the previous post, ISO 32 or 37 was suggested. I'll see if I can get myself some before taking the gearbox/engine apart. 

[Tony Brooks]

26 minutes ago, spicemouse said:

in gear and nothing around the coupling moved. Better photo of it here:
 

 

It could be the hydraulic oil being depleted as I've only topped it up with about 100ml of what was left in a bottled marked "Hydraulic oil".  From the previous post, ISO 32 or 37 was suggested. I'll see if I can get myself some before taking the gearbox/engine apart. 

 

There is no gearbox, just a hydraulic pump in the reservoir. It may be that your pump is below the reservoir, but I don't think so. The photo from the last topic shows a sort of silver disk thing mounted on the flywheel housing. This needs to come off to look at the drive plate. You may need to lift the whole reservoir off and the motor may be inside it.

 

I think any hydraulic oil sold for hydraulic equipment would be suitable. Try farmer's suppliers or motor factors. I would expect it to look and feel much like engine oil. 

[David Mack]

37 minutes ago, spicemouse said:

It could be the hydraulic oil being depleted as I've only topped it up with about 100ml of what was left in a bottled marked "Hydraulic oil".  From the previous post, ISO 32 or 37 was suggested. I'll see if I can get myself some before taking the gearbox/engine apart. 

Is there not a dipstick showing what level you should be topping the hydraulic oil up to? Anything less is asking for problems.

And certainly worth checking before you take anything apart.

Edited May 30, 2022 by David Mack

[MtB]

If this is caused by lack of hydraulic oil, the missing oil will have leaked out. There is no-where else for it to go! So have a look under the engine at the hydraulic pump end (it's not a gearbox!) and under the hydraulic motor on the propshaft. Is there spilt oil swimming about? If not, then I'd say something mechanical has broken rather than fluid lost.

[Tony Brooks]

2 minutes ago, David Mack said:

Is there not a dipstick showing what level you should be topping the hydraulic oil up to? Anything less is asking for problems.

And certainly worth checking before you take anything apart.

 

The level indicator may be a sight glass on the side of the tank but as long as the pump inlet is covered the system should work but with lower levels risk cavitation damage in the pump and possibly the motor. If there is no dipstick of sight glass I would fill to about 50mm from the top.

[spicemouse]

2 hours ago, MtB said:

If this is caused by lack of hydraulic oil, the missing oil will have leaked out. There is no-where else for it to go! So have a look under the engine at the hydraulic pump end (it's not a gearbox!) and under the hydraulic motor on the propshaft. Is there spilt oil swimming about? If not, then I'd say something mechanical has broken rather than fluid lost.

Nothing obvious, and I'm sure it would be very obvious if it was the case! There is about 2m of floor I can't access where the pipe go, so could potentially have a split under there. I'll get access to that section when I can. 

 

 

2 hours ago, David Mack said:

Is there not a dipstick showing what level you should be topping the hydraulic oil up to?

 

2 hours ago, Tony Brooks said:

 

The level indicator may be a sight glass on the side of the tank but as long as the pump inlet is covered the system should work but with lower levels risk cavitation damage in the pump and possibly the motor. If there is no dipstick of sight glass I would fill to about 50mm from the top.

No dipstick or glass sadly. I used clean white cable tie to check, and I'd estimate the oil is about 5cm from the top. 

[spicemouse]

3 hours ago, Tony Brooks said:

There is no gearbox, just a hydraulic pump in the reservoir. It may be that your pump is below the reservoir, but I don't think so. The photo from the last topic shows a sort of silver disk thing mounted on the flywheel housing. This needs to come off to look at the drive plate. You may need to lift the whole reservoir off and the motor may be inside it.

From the images below, do you think removing the green hydraulic unit would require draining the oil inside first? 

 

[Tracy D'arth]

I reckon that if you take the water hoses off the heat exchanger, the 3 bolts on either side of the red casting in the angle irons, and the bolts holding the two red castings together, you will be able to pull the whole assembly back without draining the oil.

That will get you to the coupling between the engine and the pump which I would expect to be a rubber cushion drive coupling, and likely sheared.

[springy]

There should be a relief valve somewhere which if stuck or failed open might cause the same symptoms, no idea where it would be located though.

 

springy

[MtB]

40 minutes ago, springy said:

There should be a relief valve somewhere which if stuck or failed open might cause the same symptoms, no idea where it would be located though.

 

springy

 

Good call. If the spring borked itself, that would give exactly the symptoms the OP describes.

[BEngo]

38 minutes ago, springy said:

There should be a relief valve somewhere which if stuck or failed open might cause the same symptoms, no idea where it would be located though.

 

springy

In this sort of set up any relief valve is usually inside the reservoir/ pump unit cos that simplifies the pipework⁹.  It may be part of the valve block, or be a separate item.

 

N

[spicemouse]

43 minutes ago, springy said:

There should be a relief valve somewhere which if stuck or failed open might cause the same symptoms, no idea where it would be located though.

 

springy

 

1 minute ago, BEngo said:

In this sort of set up any relief valve is usually inside the reservoir/ pump unit cos that simplifies the pipework⁹.  It may be part of the valve block, or be a separate item.

 

N

There isn't much in the way of access to the reservoir. You can see in the photos that if it's to be opened, it'll require draining of the coolant system and the hydraulc system, and likely lifted out.. Worrying! 

Any ideas what this might or might not look like? 

[springy]

Where is the control valve - if it is also inside the reservoir then unfortunately then the PRV will most likely be inside as well, if the control valve is external then as BEngo said it could be part of the control valve but my guess would be on the pump itself so that when the PRV opens oil is just returned to the reservoir.

 

If you remove the filler cap you might, with the aid of a torch (or even an endoscope), be able to see some movement in the oil when the engine is running (it might need some oil removing temporarily to make movement more obvious) which might give a clue.  

 

springy

[spicemouse]

19 minutes ago, springy said:

If you remove the filler cap you might, with the aid of a torch (or even an endoscope), be able to see some movement in the oil when the engine is running (it might need some oil removing temporarily to make movement more obvious) which might give a clue.  

I'll give that try tomorrow, thanks!

[Tracy D'arth]

Where is the oil filter?  All hydraulic systems need a filter. Could this be the problem?

 

How did the drive fail;  slowly or suddenly?

[spicemouse]

1 minute ago, Tracy D'arth said:

Where is the oil filter?  All hydraulic systems need a filter. Could this be the problem?

 

How did the drive fail;  slowly or suddenly?

I'm pretty certain there isn't any sort of filter on this system. Unless it's directly below the sump which would be a staggeringly bad design! 

Maybe the pressure feed has one build in? I could try remove the hose and see if it has something that dips into the oil. 


Failure was sudden. It often slips back from full forward (and had done for some time as a previous owner added a bracket to hold morse in place!), but it's never dropped power before. 

[Mike Adams]

Have you checked that there is nothing jamming the propeller and it rotates freely. I have a similar set up and when my daughter was using the boat she managed to get a fender stuck between the prop and the hull. The symptoms were as you described because the PRV came into operation immediately with no drive in forward or reverse. once the fender was removed back to normal

[spicemouse]

14 minutes ago, Mike Adams said:

Have you checked that there is nothing jamming the propeller and it rotates freely. I have a similar set up and when my daughter was using the boat she managed to get a fender stuck between the prop and the hull. The symptoms were as you described because the PRV came into operation immediately with no drive in forward or reverse. once the fender was removed back to normal

I was able to turn the prop by hand (though it's always a struggle). I checked yesterday after it happened and never wanted to find a rope or old mattress more! 

[Mike Adams]

34 minutes ago, spicemouse said:

I was able to turn the prop by hand (though it's always a struggle). I checked yesterday after it happened and never wanted to find a rope or old mattress more! 

Sorry I should have read the post more carefully. It sounds like a mechanical failure rather than anything else. Can you turn the prop when the control lever is in forward or reverse as well as neutral? You should have some resistance in forward or reverse. If you slacken off the feed pipe from the pump attached to the engine (it will be one of the two larger ones) and turn the engine over without starting it you should get oil spilling out of the joint. If you don't get oil either the pump has failed, the drive coupling failed or possibly the prv stuck open if it is within the tank. If you do get pressurised oil I would look at the motor (prop shaft end). Could you post a picture of the spool valve controlled by the cables or is that integrated with the drive motor.

[spicemouse]

13 hours ago, Mike Adams said:

Can you turn the prop when the control lever is in forward or reverse as well as neutral? You should have some resistance in forward or reverse.

Yet to try this, but I'll give it a go today. 

 

My control thing looks like this: 

 

I don't know if it's any help, but it's the only other point on the unit I've not shown! 

Today I've checked the levels more carefully and they are quite a bit down on what I'd expect, far more than I though. I can see some of the mechanism inside when I remove the vent. Some of it is discoloured like it was covered in oil for a long time. It's all exposed now and I can see no oil at all while the engine is on or off (in gear). 
This leads me to think I have leaked some oil somewhere, so currently removing rear floor looking for a split (nothing so far). 

Can anyone recommend where I could buy some iso32 in person? I'm near Cheshunt if that helps. Doesn't seem like something I'll get in Halfords! 

[Tony Brooks]

7 minutes ago, spicemouse said:

Can anyone recommend where I could buy some iso32 in person? I'm near Cheshunt if that helps. Doesn't seem like something I'll get in Halfords! 

 

ISO32 is an international standard document that may or may not apply to hydraulic oil. As I told you I think any hydraulic oil sold for hydraulic machinery will do. Halfords is unlikely to stock it, but a commercial motor factors or farmer's supply company like Mole will almost certainly stock it. I expect it will look much like engine oil and some suppliers sell duel purpose oil - hydraulic or engine.

[Alan de Enfield]

9 minutes ago, spicemouse said:

Can anyone recommend where I could buy some iso32 in person? I'm near Cheshunt if that helps. Doesn't seem like something I'll get in Halfords! 

 

I use a next day delivery on ebay.

Any "ISO 32 hydraulic oil" will do.

 

 

2x10L FANFARO ISO 32 HV High Viscosity Hydraulic Oil DIN 51524-2/51524-3 MS 1004 | eBay

 

Mannol 20L ISO 32 Hydraulic Oil High Grade Shell Tellus Jack Screwfix Filters 4036021163147 | eBay

 

I find the 10 litre drums are far easier to handle when trying to pour, they are smaller and stow away more easily, and a handy size to use fr cleaning out dirty bilge water.