Hydraulics - Bleeding hydraulics

Nasher · 17 April 2004, 21:47

Hi everyone, I'm getting round to finishing off the re-fit of my Ocean 6.25 and have fitted hydraulic steering sourced second hand.

I'm just waiting for the pipes to be delivered, then I can think about bleeding the system. Does anyone have any tips on technique and which fluid to use?

The system has a filler hole in the pump unit and a bleed nipple for each stroke on the ram.

Also still looking for a spare prop for the Johnson 150VRO, and spare wheel, or wheel and tyre, for the trailer - 185/R14 with 5 stud 160mm PCD.

Thanks

Nasher.

Pete7 · 17 April 2004, 22:12

Your first problem will be working out which way round the hoses go. You wont be the first or last to connect them up the wrong way round, been there done that.

Fill the cylinder (under the steering wheel) and make damn sure it stays full. A second pair of hands is helpful. If you dont then an air bubble will get in and your back to square one yes this is snakes and ladders time.

There is a bleed nipple at each end of the ram. Connect a 18" piece of tubing to it and put it in a milk bottle. This stops hydraulic oil going all over your nice deck. Undo the bleed nipple (side A) and turn the wheel, if you have undone the right side then fluid will start to travel down the lines and eventually out of the nipple, you should have a constant flow without bubbles eventually. tighten the nipple and keep turning the wheel and the engine moves as the fluid fills the ram. Stop and tighten the nipple when its at its full lock.

Now move to the otherside (side B) of the ram and repeat but obviously turn the wheel the other way. DO NOT turn the wheel back or air may get into the line with hudraulic fluid in it. When the fluid comes out of the nipple without air bubbles, tighten the nipple. Move back to the first nipple (side A) and release it. Continue turning the wheel the same way!!! and the ram will move back through the centre position to the otherside which will force air out of the ram on the first bleed side (side A). Tighten side A nipple and move to side B nipples and undo. Turn the wheel in the opposite direction and air will forced out of the ram on side B.

Continue like this for about an hour. When the deck is very slippy with hydraulic fluid and its running down your console you have probably succeeded. tighten the nipples and give the steering a good seeing too. If there are any notches then you have air in the lines or ram. Its impossible to get it all out but it should feel nice and smooth from lock to lock. After the boat has been given a good thashing at sea the air collects in the cylinder and can be topped up occasionally.

Pete

Pete7 · 17 April 2004, 22:14

Oh yes if you did connect them the wrong way round change them over on the cylinder and go back to paragraph 1.

You will need at least 2L of oil the first time you do this and a third might be prudent. You can always keep it in the boat.

Do not re use any oil as hydraulics require spotlessly clean fluid or the seals go put!
Pete

Nasher · 17 April 2004, 22:17

Thanks Pete, you are always very helpful.

Nasher.

Pete7 · 17 April 2004, 22:22

Shout if you need a hand to do it as you are only down the road. Although its not difficult if you remember that both lines and ram have air which needs removing one way or another.

Pete

Nasher · 17 April 2004, 23:07

Very kind of you to offer, I'll shout if I get stuck. I've built a few custom motorbikes in the past matching up different master cylinders and calipers, bleeding some of those turned into nightmares.

I've been thinking that so many of us are based around the solent we should think about arranging a pub evening to meet up and talk RIBS. over a beer or two.

Nasher

Pete7 · 17 April 2004, 23:13

Brilliant, party at Nashers house Monday night.

Two dozen experts all saying "you don't want to do it like that"

But yes we should,

Pete

Nick Hearne · 19 April 2004, 12:29

Well this all sound great, I have fitted hydraulic steering but for some reason it has been fitted over the deck! As I have under deck cabling I have been considering rerouting it under the deck to keep it all tidy. So if I go this rout would I be best to disconnect the hoses at the engine, plug them in some way reroute them under the flour connect them back, then bleed them of air in the hope of minimal bleeding will need to be done!
Sound good in theory.

Any thoughts?
Nick

Nasher · 19 April 2004, 12:56

Nick

Sounds like your best option to me, might be worth you investing in some proper blanking off fittings from a hydraulic hose supplier, you don't want anything improvised to come out whilst between the decks.

Regards

Simon.

CJL · 19 April 2004, 17:08

I`ve found the secret to Hydraulics!

My hydraulics failed a few hours before I wanted to use my old Delta and I was disgusted at some of the prices and time marinas wanted for the work (Remove a thread from the hydralic unit, replace pipe and refilled £200+ in about 2 weeks)

I had a quick gander through Yellow Pages and found Pirtek. (www.pirtek.co.uk)(Freephone (Local Centre) 0800 38 24 38) They normaly do heavy plant and Hiabs, through a call out service. Rather than pay a call out fee I took my boat to one of their depots and they removed the broken thread, replaced it, (pipe did not need replacing as they had specialist gear to put a new end on) refilled it all and gave me 5 litres of hydralic oil for £35. The whole think took twenty mins.
Cannot recommend them highly enough.

Hope this helps

Chris

Cookee · 19 April 2004, 17:55

If it is Seastar steering I know that you should use the fluid thier own oil as it is a different specification to regular hydraulic oil - I assume it is because of the type of seals they use? If in doubt RTFM!

John Kennett · 19 April 2004, 18:09

I can recommend Pirtek too. Their service centres keep just about everything in stock (in small quantities) and have some very helpful staff.

They are on the web at www.pirtek.co.uk

John

Jelly · 20 April 2004, 08:31

Just been doing some hunting on why my hydraulic steering is notchy and pushes oil out of the steering resevoir.
The UK importers for Lecombe & Schmitt told me it was probbably air in the lines

Was told to remove the ram from the outdrive unit and get it above the helm unit to aid in bleeding also on these helm units (30 HB CAR pump 2200950) there should be an air gap of 15-20mm in the top of the resevoir when the ram is out to compensate for the fact I've got an unballanced ram.
So here's to Dextron II every where as I'm sure to make a mess!
Hope it helps
Jelly

Pete7 · 20 April 2004, 08:53

Jelly, never needed to raise it and not sure that is going to work. The only time big bubbles move is when the hydrualic oil is pumped through the lines. Suggest you just bleed it and it should be miles better.

Do note however that as the summer approaches the cylinder will heat up and the oil expand. A small amount will be lost at the weakest point normally the ram but we are talking a tea spoon full. Releasing the pressure on a hot day helps to stop this.

Pete