Hydraulics

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basewindow
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Hydraulics

Post by basewindow »

In a previous post I said I had my hyraulic arms stuck in the 'up' position.

The problem has been that I can't remove the top plate (To check the unload valve etc) because the rocker catches on the back of the case.

Hence my problem, arms are stuck up, but I can't get the top off to check the valve, because the arms are up.

So whats' the solution?

Can I force the arms down by placing something very heavy on the raised draw bar?

Or will this cause some damage?
Last edited by basewindow on Thu Jul 09, 2015 3:43 am, edited 1 time in total.
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Brian
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Re: Hyraulics

Post by Brian »

If you take off the ASC at the front of the lift oil will leak out of the ram cylinder and let the arms down. Be Aware oil will go everywhere!

I have also released the oil from the ram cylinder by moving the ASC valve into a half way position between ram cylinder and auxiliary service with the quadrant lever in lower. Bit tricky but far less messy.
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basewindow
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Re: Hyraulics

Post by basewindow »

Excuse my ignorance.
Just remind me what and where I would find the ASC?
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basewindow
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Re: Hyraulics

Post by basewindow »

It's ok I found my manual - Aux Service Control - under the flow control knob?
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Re: Hyraulics

Post by Brian »

Image

Flow control is part of the ASC, four bolts and a small one in the centre of the unit to remove it.
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basewindow
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Re: Hyraulics

Post by basewindow »

I've had that off before with no success..

No oil leaked out and arms still up. Or am I not getting it?

ASC Off..

Image

With ASC on?


Image
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Re: Hyraulics

Post by Brian »

Oooops! That looks pretty serious! If you have no oil in the ram cylinder it must be a mechanical lockup. It could be seized arms, piston or even the piston rod stuck.

First thing to do, slacken off the arm retaining bolts and apply a medium tap to the arms. Sometimes the retaining bolts can be over tightened which jams the arms against the housing. Splash plenty of easing oil/diesel around the area where the arms fit onto the cross shaft.

Second thing would be to remove the PTO selector and get a light and possibly a mirror in there to see if the piston rod is free or jammed. If the rod is jammed it will mean the piston is stuck in the ram cylinder. You can try pouring easing oil into the centre holes where the ASC comes off, one is slightly larger then the other and both lead down to the ram cylinder. You might also remove the cylinder relief valve and get some easing oil down there too.

The final way may or may not work, I have never had to try it, Remove the bolts holding the ram cylinder to the top cover. The cylinder is dowelled into the top cover as well as bolted so you may have to lightly tap the loosened bolts to get it to drop free. That should free you enough room to get the top cover off you should be able to see through the PTO plate. in your picture it looks as if you already have three of the bolts slackened off leaving just the one under the ASC.

Be aware that if there is oil in the ram cylinder and you have the ASC off, if things free up by slackening the lift arms there will be quite a fountain of oil out of the top cover.
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basewindow
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Re: Hyraulics

Post by basewindow »

Okay Brian thanks for that. It sort of makes some sense.

When I picked this machine up I was going through all the bits to see what worked and what didn't.
I pulled the quadrant lever up and the arms went up. It was only later when I was checking all the oil levels that I found out there was little or no oil for the hydraulics, so a stuck piston or piston rod could be the problem if there was no, or little oil to lube things up?
From memory I think I added 12-15L of oil before it reached the level plug.

Anyway I'll have a look at things and follow through with what you've mentioned this weekend and see what happens. Which holes with the ASC removed should the oil leak from if the piston drops the oil?

I have tried taking the arms off but they seems pretty well stuck in the splines.

I have cranked it over with the ASC off and oil pumps up so it seems the pump works okay at least.
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basewindow
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Re: Hydraulics

Post by basewindow »

Just a quick update.

I took the ASC off and put lots of lubricant down the holes and lubricated around the arms, gave them a tap, but still no action.

Looks like I'm going to have to try the last option and remove those bolts and drop the ram cylinder.

I'll let you know how it goes.
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basewindow
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Re: Hydraulics

Post by basewindow »

Okay that method worked.
Loosened the bolts, the ram cyclinder dropped off and it gave me enough wriggle room to get the top plate off.
I retrieved the cyclinder and all looks ok. Unload valve moves freely, cyclinder moves freely.
Arms still stuck up and no movement.
I assume they should just have free movement now?
So it appears they are siezed to their housing.
I have put plenty of lubricant on the inside and out and given them a good tap but nothing so far?
Any tips?
Knowing that nothing it actually siezed in there except the arms, is placing a very heavy weigh on the arms going to cause a problem?
I know they move because I saw thm move up, and stay that way....
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Re: Hydraulics

Post by Brian »

You had quite a lot of hydraulic pressure pushing them up so you would need a lot of weight to push them down. Try taking the arm retaining bolts out on either side then giving the arms some real wellie! You may have to heat them to get them to move. The cross shaft only goes out one way, there is a washer on the inside that stops it. there are phospher bronze bushes on either side in the housing, again a bit of heat on the housing itself may help.

I took one apart a few months ago and had to use heat and a 14 lb sledge hammer to get an arm off! A press would be realy handy too.
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Re: Hydraulics

Post by basewindow »

Thanks Brian.

What I was think of was bolting the top plate back on the tractor minus the ram cylinder. Connecting the three point linkage back up and using a friends front end loader to apply some downward force to the arms?

Or of course as you suggest heat, lubricant and a big hammer.

Once I free the arms (assuming I do) what is going to stop them getting stuck back up again?
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Re: Hydraulics

Post by alang »

The loader seems a bit severe and will compress the rear tyres - if you have a roll bar fitted and a bottle-jack you have the makings of a hydraulic press. Alternatively, try a heavy ratchet strap, or puller, between the yoke and drawbar - probably in conjunction with Brian's heat and hammer technique :D

basewindow
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Re: Hydraulics

Post by basewindow »

You're right the front end load was probably a bit excessive.
In the end I refitted the top place minus the ram piston and attached the arms to the TPL.
I used a 4.5' piece of steel girder I had been using as a counter weight and with a bit of thumping the arms have come down.
They are still VERY stiff and wont move up again by hand thats for sure.
How easy to move should they be?
Whats the best method to get some movement back in them?
At least I know the issue now, as long as I can put the ram piston and top plate back together correctly.......
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Brian
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Re: Hydraulics

Post by Brian »

You should be able to lift the arms up with little or no resistance, they usually flop about. Try knocking the arms sideways along the splines as sometimes people tighten the retaining bolts too much and this locks the arms. Think you need to free them before you put the top back on rather than re-fit and hope. IMHO! :D
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basewindow
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Re: Hydraulics

Post by basewindow »

Quick question.

When I dropped the ram cylinder from the top plate I didn't happen to take note of which bolts fit where.
Three are the same, one is longer.
Which fits where?
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Re: Hydraulics

Post by Brian »

Longer one goes in the back corner on the quadrant side.
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Re: Hydraulics

Post by basewindow »

Just thought Id give you an update.

WelI I now have fully functional hydraulics!

As it turned out as stated earlier what was casuing the problems was actually the arms stuck in their housing, but after much lubrication, heating, hammering and with the help of a jack, they arms now free and can be moved by hand. They are a little stiff but have full movement.

I checked the usual culprets whilst I was in there, loading value etc and they were all good, even the pin that seems to get worn away was fine.

Everything went back together easier than expected.

So thanks to all who helped and offered suggestions.

Now onto the rest of the steering......
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Re: Hydraulics

Post by Brian »

Glad to hear you are sorted.

Are you anywhere near Toura or Foster or even Bairnsdale or The Prom?
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Re: Hydraulics

Post by basewindow »

Im about 20 minutes out of Yarram. Which is about 30-40 minutes from Foster.
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