Any hydraulic experts here?

[TheRealAndy]

The keel on my rag boat is hydraulic. The ram is not the best, but it works. The problem is the pumps. There is an electric pump and a manual pump. The system keeps getting air into it, so the pumps don't work properly. I am going to try and bleed it this weekend, but not really sure how. I think the design is to blame for the problems, so wouldn't mind getting it looked at. Problem is, I have no idea who to ask or where to go. Any tips?

[Chimo]

Don't know who to ask but from what you are describing it sounds as if your oil level may be low. If that were the case it would be easy to get air in the system as you switch from elec to manual.

Have you tried topping up the tank and checking the level as you change from one to the other and back?

Cheers
Chimo

[wags on the water]

Any hydraulic experts here?
90% of members are experts Andy....just ask 'em.

[thylacene]

Speak to your local Enzed/Hydraquip etc, these guys work with hydraulics on everything, and should be able to sort it for you quick smart.

Cheers

Thy

[Marlin_Mike]

The keel on my rag boat is hydraulic. The ram is not the best, but it works. The problem is the pumps. There is an electric pump and a manual pump. The system keeps getting air into it, so the pumps don't work properly. I am going to try and bleed it this weekend, but not really sure how. I think the design is to blame for the problems, so wouldn't mind getting it looked at. Problem is, I have no idea who to ask or where to go. Any tips?


Buy a real boat Andy and sell the rag boat.................. ;D;D:P;)

Mike

[TheRealAndy]

Don't know who to ask but from what you are describing it sounds as if your oil level may be low. If that were the case it would be easy to get air in the system as you switch from elec to manual.

Have you tried topping up the tank and checking the level as you change from one to the other and back?

Cheers
Chimo

I thought the same thing, but I think the resevoir is full. Its not clear like most, so I cant see the fluid level. To fill it its a small tube with a ball valve to close it. I open the valve and try and put oil in and it just overflows. There in lies one of the problems I wish to resolve.

[FNQCairns]

Another expert here, its just a dumb power steering pump found on cars even 40 years old, buy a bottle of lucas power steering stop leak and and displace the whole bottle into it. If it doesn't improve you can dump it and spend a squillion (relatively speaking) on fixing git proper.

[Roughasguts]

Probably just needs a new seal!!l find wich one weeps, pull down and replace.

Cheers

[Chimo]

RAG could be correct but I still would sort out how to make sure the oil level was as it should be before pulling it down.

By the way the way hyd oil behaves if it has a leak perhaps it should be possible to see?

C
C

[Stik-ugly]

Is the reservoir and pump separate if so could be sucking air on the suction side of the pump

[finga]

Any pictures Andy?
How far does the ram feed in and out?
What weight is in the keel?

Is the keel hydraulically lifted and lowered or just hydraulically lifted and gravity takes it down?

[TimiBoy]

Don't get a hose Doctor. They are really good on hoses, but in my (quite substantial) experience, at the end of the hose, they run out of knowledge.

FNQ's solution sounds good, and failing that I'd grab a good Diesel Mechanic who works on trucks and machinery. They fiddle with hydraulics all the time.

Cheers,

Tim

[TheRealAndy]

I'll get some pictures when I have a chance. The pump is separate to the reservoir. Pump goes to a switch/lever/valve then off to the ram I think. It may go from the valve to the manual pump then to the ram. Its gravity down, hydraulic up. Bomb on the keel is about 300kg plus the weight of the centreboard, so probably 400-500kg all up.

It looks pretty dodgy. The reservoir is actually made up from pvc sewer pipe. The electric pump is a late addition as the boats never came with them.

The ram itself is ok. It will lift the keel up when their is fluid going to the pumps. It does slowly drop down over time, but I am guessing that could be due to the air in the system.

[finga]

When you get some pictures measure the diameter of the ram and the length of the stroke.
How fast does it have to go up?

[TheRealAndy]

Speed up is not an issue. The boat would have been fitted with manual pump originally.

[Grand_Marlin]

G'day Andy,

I can take a look if you need me to.

Cheers

Pete

[finga]

How about doing away with hydraulics and going linear actuator?
http://www.dcactuators.com/

http://techome.com.au/process/shop/productView.html?itemId=10811

[Noelm]

There may be a clue when you said it leaks down over time, this indicates a faulty seal, and it may be leaking past the seal, and not outside, so no visible leak! air will not cause a leak down, it will cause a million other faults, but not (usually) a leak down, Enzed or a good plant mechanic (as mentioned) should be able to sort you out, or call Pete who has also offered to take a look.

[seastorm]

To me it sounds like the internal seal on the ram has gone, it might also have a check valve which is faulty they are designed to stop the ram from dropping, these check valves need to be driven by the hydraulics for the ram to go down. You could give Jonlin Hydraulics a call they are at Acacia Ridge way or Hydraulic Components they are at Capalaba

[TheRealAndy]

I have no doubt the seal is faulty on the ram, but its ok for now. The only time the keel is up is when its on the trailer.

The problem I have is the pumps not pumping fluid because there is air in the line. I dont mean a little bit of air either...

Pete. I'll try bleed it this weekend (if I can figure out how) and if we have no luck I'll give you a call.

Finga, a linear actuator probably wont fit, plus its getting spashed with salt water all the time, so I doubt it would last.

[Jarrah Jack]

I've got a manual hydraulic pump for my outboard motor tilt setup and I've had to pull the lot apart more than once. If you like working on the things yourself and understanding them then it may be worthwhile to pull the lot apart and replace all the seals if things don't work out with the bleeding.

Seals are cheap. Dirt and any sort of grit is the real enemy I've found so you have to be meticulous when cleaning and working on them. Learning from someone like GM sounds a good idea.

[wags on the water]

Have you checked your oil level? If the level is low, this would have a similar affect to air being in the line. - This is one of the problems with the gear we are given.

[cormorant]

Is your rag boat a class boat? . Most of the class associations have a pretty good knowledgebase of parts and may be able to tell you exactly what seal , bucket, oring ( part number, brand or dimensions) is possibly stuffed or if it is just a bleeding issue.

To bleed most hyd stuff that doesnt have specific bleed points it is usually a case of manually pumping while locked off until bypass happens and then open the valve to ram briefly and continue. The high pressure going in bleeds air as it cycles. Always faster to manually prime everything in it's best possible position ( upright)) upper hose loosened off to minimise air in system. Newer fluids will absorb less water so worth changing since you have to bleed it anyway and checking filter grilles if it has any as any small grit will causea seep if it ends up in valve.

[TheRealAndy]

Have you checked your oil level? If the level is low, this would have a similar affect to air being in the line. - This is one of the problems with the gear we are given.

I think the oil level is ok, but its hard to tell. The reservoir needs a level tube or something so you can tell.


Is your rag boat a class boat? . Most of the class associations have a pretty good knowledgebase of parts and may be able to tell you exactly what seal , bucket, oring ( part number, brand or dimensions) is possibly stuffed or if it is just a bleeding issue.

To bleed most hyd stuff that doesnt have specific bleed points it is usually a case of manually pumping while locked off until bypass happens and then open the valve to ram briefly and continue. The high pressure going in bleeds air as it cycles. Always faster to manually prime everything in it's best possible position ( upright)) upper hose loosened off to minimise air in system. Newer fluids will absorb less water so worth changing since you have to bleed it anyway and checking filter grilles if it has any as any small grit will causea seep if it ends up in valve.

It is a class boat. but getting on now so not so many racing in big groups. Its very hard to get info on them. I think the main problem is that when I bought it, it was set up for cruising, not racing, and part of this was the electric pump. I dont think the job was done very well and to be honest I am thinking about getting rid of it.. The manual pump is just like a bottle jack and when it has enough fluid going to it (no air locks) then it works just fine.

I will try get down to the boat tomorrow and take some pics.

Not sure I understand the manual prime thing. The ram has a high pressure line from the pump at one end, then a low pressure line at the other end (with a ball valve inline) that goes back to the reservoir.

The problem with pumping it, is I can see the airlock in the low pressure tube going to the pump, this is the airlock I need to remove.

There is some details here on how to operate it as standard in the owners manual.: http://www.johncrawfordmarine.com.au/trailer-sailer/library/cat_view/27-trailer-sailer-library/106-binks-25?limit=20&limitstart=0&order=hits&dir=ASC

[oldboot]

Remember.....don't assume that it ever worked properly in its current form.

cheers

[cormorant]

Ah yours doesn't have a up/down valve as such so what I suggested is not worth a pinch of......

Need to get the air out and , fresh fuid and see where you stand on whether the pump or rams need seals

If you have to pull it apart and find any grit pull the whole thing down as the ball valve seals in them are tiny and you'll just keep having to do it otherwise.

[TheRealAndy]

Ah yours doesn't have a up/down valve as such so what I suggested is not worth a pinch of......

Need to get the air out and , fresh fuid and see where you stand on whether the pump or rams need seals

If you have to pull it apart and find any grit pull the whole thing down as the ball valve seals in them are tiny and you'll just keep having to do it otherwise.

It does have an up down valve associated with the electric pump. When you pull the lever up, it has a switch on it that turns the pump on. When you push the lever down, it obviously releases the pressure in the ram and lets gravity take the keel down.

The whole lot works fine when there is enough fluid in the low pressure lines. It does sound like there is not enough fluid in the reservoir, but I just can tell. I try to top it up and no more will go in.

[seastorm]

I have done some work on three phase hydraulic pumps before, one thing we used to check when first running them was to make sure the motor was running the right way if it wasn't the hydraulic pump used to bubble the oil in the tank with air. The other thing you could try is there should be a pressure bypass valve, you could back this off so there is little to no pressure in the system ( the keel will not lift) and run the hydraulic in the lift sequence the oil should run through the system and the air should come out.

[Spaniard_King]

I would put my hand up Andy but I am not sure when I am up your way next.

the best I can give is that to fill the system fromm the highest point available and iff possible, set up a reservoir whilst you bleed the system.

clean all seal areas as dry as possible and look for leaks.. if it needs oil it has a leak..generally.

[MackerelMan]

Are the two pumps iscolated ie is one sucking thru the other. Also is there an inline suction strainer perhaps in the reservoir that is blocked.

[TheRealAndy]

I have done some work on three phase hydraulic pumps before, one thing we used to check when first running them was to make sure the motor was running the right way if it wasn't the hydraulic pump used to bubble the oil in the tank with air. The other thing you could try is there should be a pressure bypass valve, you could back this off so there is little to no pressure in the system ( the keel will not lift) and run the hydraulic in the lift sequence the oil should run through the system and the air should come out.


Definatly runs in the right direction, cause it works ok most of the time.


Are the two pumps iscolated ie is one sucking thru the other. Also is there an inline suction strainer perhaps in the reservoir that is blocked.

Good question. I have not looked at where the two pumps join up, but the way I ASSUME it worked is the high pressure side (output) of the two pumps is connected with a T Piece. I could be wrong. If I get a chance to get to the boat tomorrow I will whip the cover off the manual pump and see where the lines all go. I'll also sketch up a diagram of where all the hoses and pipes go.

[TheRealAndy]

Bit the bullet and called my old man who is a retired hydraulics engineer.

It has to be low fluid in the reservoir, but I cant for the life of me figure out how to get more in there.

Also, after talking to the old man I reckon the valve that joins the outputs of the manual and electric pumps is faulty or the wrong part. Supposed to be a one way valve but it certainly does not work.

[TheRealAndy]

Bingo to those who said low oil! I thought this was the case, but just couldn't figure out how to fill it when it kept coming out the filler. I dont get on well with my family at all, so really had to swallow my pride to call the old man, but I guess it was worth it in the end.

To fill it you need a container like those one man brake bleeders you use on the car, except it has to be gravity fed. Pretty much a big funnel with a lid. Hook the filler tube to the funnel and open the valve. Lower and raise keel a couple of times until all air is gone.

There is also a faulty check valve on the manual pump, but to fix that will need the pump to be pulled down. Need to find someone who can rebuild the manual pump that was made in the early 80's now.

The cylinder/ram is ok. Its got a leak where the low pressure line is, but should only need the ball valve replaced that is used to lock the keel down. Most likely someone has tried to raise the keel with the ball valve shut.

[Chimo]

Glad you got it sorted, ............

Cheers
Chimo