Lost hydraulic drive

[spicemouse]

Thanks @Tony Brooks & @Alan de Enfield, I'll try and get myself some of the stuff and see if a top up helps before spending more money. 

No obvious leaks under the floor though, so a bit of a mystery where it could have gone. 

[john.k]

Hydraulic pumps sometimes have a steel spline drive into the motor flywheel which runs dry ,and turns into red dust ...............cure is splodge of moly dag on the spline ....works even when the moly is dry..........of course the moly must be applied before the spline flogs out.

[Tracy D'arth]

57 minutes ago, spicemouse said:

Thanks @Tony Brooks & @Alan de Enfield, I'll try and get myself some of the stuff and see if a top up helps before spending more money. 

No obvious leaks under the floor though, so a bit of a mystery where it could have gone. 

I thought you said previously that the level was 5cm from the top? Now you say it is so low that you can see the mechanical bits in the tank.  Confused.

[spicemouse]

2 minutes ago, Tracy D'arth said:

I thought you said previously that the level was 5cm from the top? Now you say it is so low that you can see the mechanical bits in the tank.  Confused.

I was using a... substandard method of measuring. I didn't think I could open the air valve completly to see in. I've gone from trying to stick something through a tiny hole to looking in. 

[koukouvagia]

2 hours ago, Alan de Enfield said:

 

I use a next day delivery on ebay.

Any "ISO 32 hydraulic oil" will do.

 

I was advised by ARS Diesels who fitted and serviced my hydraulic drive to use ISO 46 also to avoid the biodegradable oil which doesn't, apparently, last as well.

There are plenty of suppliers online.  I don't know how much difference there is between 36 and 46.

[Mike Adams]

2 hours ago, spicemouse said:

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! 

 

2 hours ago, spicemouse said:

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! 

I use 37 grade which you can get on ebay. looks like your unit has the control valve, prv all within the same housing ie the tank. Are there any indications of the manufacturer? Try ARS but I suspect it is quite old. Was it original to the boat and how old? If you are not getting any oil flow when filled up I think you need to take the unit off. Shouldn't be that difficult but remember with hydraulic systems absolute cleanliness it essential.

[Alan de Enfield]

43 minutes ago, koukouvagia said:

I was advised by ARS Diesels who fitted and serviced my hydraulic drive to use ISO 46 also to avoid the biodegradable oil which doesn't, apparently, last as well.

There are plenty of suppliers online.  I don't know how much difference there is between 36 and 46.

 

I was advised by my local oil 'manufacturer) (Witham Oils) to use the '32' across the fleet of diggers, tractors and hydraulic mowers as it is 'better' for the more 'elderly' equipment in year round use.

 

That's what I use and have had no problems, but if you are hapy with your 46 then thats another option.

 

The 32 is readily available at all the local farm supplies as well as ebay.

 

Google says :

 

 

What is the difference between ISO 46 and ISO 32 hydraulic oil?

What is the difference between ISO 46 and ISO 32 hydraulic oil?
32 is thinner, No. 46 is medium and No. 68 is thicker. Generally speaking, if the temperature is low in winter, use #32 & #46 hydraulic oil with a lower viscosity, and use #68 hydraulic oil with a higher viscosity in summer.

[Tracy D'arth]

I thought you said previously that the level was 5cm from the top? Now you say it is so low that you can see the mechanical bits in the tank.  Confused.

 

 

 

 

I would be concerned that there seems to be no oil filter.

[adrianh]

If you cannot find any quantity of missing oil and the oil level slowly drops after you have topped it up, then the next possibility is oil loss internally in the bowman cooler.

Is the water side of this cooler on raw water pumped from the canal or is it part of skin tank cooling system along with the engine cooling?

If the latter then oil will appear in the header tank for the cooling system.  If the former then you will not see spillage if it is only a small amount being lost 

Bowman coolers have a removable tube stack sealed each end with a squeezed rubber O ring. The O rings do fail if they are run hot for long periods. The cooler looks very small, what temperature does the oil reach when this system has been working hard?

If the pump has a tapered drive shaft and the coupling becomes loose then this can give you your symptoms. 

In theory the pump will be mounted and sealed in the tank as it is horizontal, so removing from the engine adaptor should not loose oil.

If you have a coupling failure I may be able to help identify one.. I have 40 plus years on industrial hydraulic systems

[john.k]

Cooler leak should either fill the cooling system with oil sludge,or if its direct overboard,then you should be seeing an oil slick in the wake .....bad situation if.....

[spicemouse]

UPDATE:

I added more oil and the system still doesn't work. I can see the oil now when the engine is running and "in gear", and the oil doesn't move. 

I had a mechanic over last night and he agrees with most of you, it's likely the prv or control system inside the box. As the box is basically a sealed unit there isn't much he can do except help me remove it so we can sent it off to a specialist for either disposal or repair. 

I've contacted ARS which seems to now be BSP hydraulics, and Hercules Hydraulics. I think I'll be faced with the option of replacing the whole system as no one wants to deal with really old units with no spare parts. It's sounding very expensive! 

 

On 31/05/2022 at 22:38, adrianh said:

Bowman coolers have a removable tube stack sealed each end with a squeezed rubber O ring. The O rings do fail if they are run hot for long periods. The cooler looks very small, what temperature does the oil reach when this system has been working hard?

I don't honestly know how hot it gets, but I'll find out when we remove the cooler to get the hydraulic unit out. 

 

On 01/06/2022 at 04:03, john.k said:

Cooler leak should either fill the cooling system with oil sludge,or if its direct overboard,then you should be seeing an oil slick in the wake .....bad situation if.....

I don't think the drop in oil (a few cm over a long time) would show in the skin tank coolant?

 

Either way, as the top up didn't fix it, any loss of oil is either negligible or will be fixed by the replacement/repair of the system. 

 

[BEngo]

Before you remove it have you tried loosening the pipe connections to the motor one at a time, with the engine going and first forward then reverse selected?

 

You should get  oil from one connection in either ahead or astern. And from the other connection, in the opposite direction.  The oil should be under fairly high pressure, so don't get too enthusiastic with the loosening, and keep your skin à out of the line of any jets of oil.

 

 There may be a third, overpressure relief pipe,  but this should not be under much pressure.  If it is there will be oil in both ahead and astern but not in neutral, and there is probably a motor problem.

 

If no oil from any pipes then the box is the next step. 

If you get oil then the motor is the next step.

N

[Tony Brooks]

13 minutes ago, spicemouse said:

UPDATE:

I added more oil and the system still doesn't work. I can see the oil now when the engine is running and "in gear", and the oil doesn't move. 

I had a mechanic over last night and he agrees with most of you, it's likely the prv or control system inside the box. As the box is basically a sealed unit there isn't much he can do except help me remove it so we can sent it off to a specialist for either disposal or repair. 

I've contacted ARS which seems to now be BSP hydraulics, and Hercules Hydraulics. I think I'll be faced with the option of replacing the whole system as no one wants to deal with really old units with no spare parts. It's sounding very expensive! 

 

Thanks for the feedback. Unless your mechanic knows how the drive is transmitted to the pump I don't see how you an rule out a drive plate failure.

 

I don't for a minute believe the reservoir was welded up after the pump and control was fitted, so I don't think it is a sealed unit. It may be just that you have not found the way in yet.

 

If it were a PRV failure then I would still expect to see oil movement a sit vented back into the reservoir.

 

I think that once the whole unit is away from the engine you will see nuts or bolts that you can undo to remove the adaptor plate and that may be the way in. I think that you need to talk to your local hydraulic engineers. Depending upon the type of pump it might be possible to fit a much cheaper type with a degree of loss of efficiency. Remember plant operators and farmers are not known to be keen on paying a "marine premium".

[spicemouse]

1 hour ago, Tony Brooks said:

I don't see how you an rule out a drive plate failure

There was no rattling before the failure, and it doesn't sound like something is bumping around in there now. We were thinking if the drive plate failed you'd know about it, but if the prv or control valve failed it would be quiet but instant. 

[Tony Brooks]

8 minutes ago, spicemouse said:

There was no rattling before the failure, and it doesn't sound like something is bumping around in there now. We were thinking if the drive plate failed you'd know about it, but if the prv or control valve failed it would be quiet but instant. 

 

Fair enough, your choice, but to get the reservoir off you will almost certainly expose the drive, whatever it is, so you can inspect it. Much better to look at the simple and cheaper things before worrying about big money repairs.

[spicemouse]

Just now, Tony Brooks said:

 

Fair enough, your choice, but to get the reservoir off you will almost certainly expose the drive, whatever it is, so you can inspect it. Much better to look at the simple and cheaper things before worrying about big money repairs.

Absolutely, I hoped it was the prop stuck, then the cable, then low fluid... Now I'm hoping it's the drive plate! But as the only way to get to it is to remove the box (and I think drain the cooling system), I am resigned to that fate.   

[Tony Brooks]

1 minute ago, spicemouse said:

Absolutely, I hoped it was the prop stuck, then the cable, then low fluid... Now I'm hoping it's the drive plate! But as the only way to get to it is to remove the box (and I think drain the cooling system), I am resigned to that fate.   

 

If the inlet and outlet of the oil cooler go to hoses then you could just clamp them rather than drain the cooling system. I think you will have to drain the reservoir unless you can get some kind of lifting device to take the weight.

[Mike Adams]

I suggest you do what Alan has said and slightly loosen the two larger pipes startthe engine in neutral and if you go into forward or reverse you should see oil leaking out. If you don't just whip the 3 pipes off, unbolt the cooler from the back of the unit, undo the 4 bolts securing the pump to the engine and lift it out. I suspect the drive is broken. I think the drive is broken. splines are gone or flex coupling if it has one.

[spicemouse]

8 minutes ago, Tony Brooks said:

 

If the inlet and outlet of the oil cooler go to hoses then you could just clamp them rather than drain the cooling system. I think you will have to drain the reservoir unless you can get some kind of lifting device to take the weight.

be very tricky to do anything other than drain the coolant as the pipes are fixed copper, not really enough flex in the system to allow moving the box back. 

3 minutes ago, Mike Adams said:

I suggest you do what Alan has said and slightly loosen the two larger pipes startthe engine in neutral and if you go into forward or reverse you should see oil leaking out. If you don't just whip the 3 pipes off, unbolt the cooler from the back of the unit, undo the 4 bolts securing the pump to the engine and lift it out. I suspect the drive is broken. I think the drive is broken. splines are gone or flex coupling if it has one.

Sadly they are of a size I don't have in my toolbox, I'll ask around and see if anyone on a nearby boat has a large enough spanner. 

[Tony Brooks]

9 minutes ago, spicemouse said:

be very tricky to do anything other than drain the coolant as the pipes are fixed copper, not really enough flex in the system to allow moving the box back. 

 

Now having seen the photo I agree, pity.

[adrianh]

As has been said, you will need to separate the tank from 

The engine to make sure that the drive is connected. The drive to the pump will be through some sort of flexible coupling, probably of industrial origin.  It is also possible that pipework within the tank has broken, I have seen this type of fault many times.

If you are not in to much of a hurry I can help you with repairs without going to the expense of all new parts. Be aware that anything hydraulic does not come cheap!

[spicemouse]

7 minutes ago, adrianh said:

If you are not in to much of a hurry I can help you with repairs without going to the expense of all new parts.

Where are you based? I'm currently around the Cheshunt area. I have limited water and cassette capacity, so I'm in a little bit of a hurry but not much I can do about that! 

[Tracy D'arth]

By now I would have cut a hole in the rear part of the drive plate housing to be able to see the coupling. A 1" hole saw would do.

 

Most of the hydraulic drives I have seen use a rubber cushion coupling element, when they shear they don't make a noise.

[john.k]

In many cases its easier to move the engine forward ,rather than the gearbox back......................anyway ,cutting a hole in the housing sounds like a clever wheeze.................sort of like cutting a hole in the firewall of the bosses car to replace a welch plug.......hidden by the floormat,until he traded the car !

[spicemouse]

47 minutes ago, Tracy D'arth said:

By now I would have cut a hole in the rear part of the drive plate housing to be able to see the coupling. A 1" hole saw would do.

That sounds a bit scary! I might be able to move it back a few cm to get a look