Volcano gearbox

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AussieLeyland
Posts: 3
Joined: Wed Apr 25, 2018 1:07 pm

Volcano gearbox

Post by AussieLeyland » Wed Apr 25, 2018 1:16 pm

Hi, I'm wondering if anyone has come across this fault before....

My BMC mini's three point linkage went down and refused to lift again. I suspected it was hydraulic pump at first, but she's now erupting oil out around the gear levers and somewhere under the fuel tank.

Ít seems a bit bizarre to me, as I thought the hydraulic lift on these is completely external to the gearbox unlike the bigger Leylands.

Any ideas on what's gone wrong?



Ley154
Posts: 70
Joined: Sun Apr 01, 2018 8:22 am
Great Britain

Re: Volcano gearbox

Post by Ley154 » Thu Apr 26, 2018 6:34 am

Hi. The hydraulic lift ram seal has failed. This allows the hydraulic oil ( same as the engine oil by the way) past the lift piston into the upper part of the lift casing. There is a drain hole from the casing into the top of the rear axle housing so any leaking oil gradually fills up the back axle and gearbox until it comes out of the breather under the fuel tank. You should have noticed that the level in the hydraulic tank kept going down mysteriously.
Rectification: Put a large tray under the rear axle below the hydraulic filter, remove the level plug just in front of the filter and let the oil drain out of the box until it gets to the correct level - expect a few gallons to come out. Whilst there remove the hydraulic filter which will drain the remains of any oil in the hydraulic tank and fit a new filter. The element is the same as a Morris 1000 or 850 Mini car engine filter. At the back of the tractor remove the pto chain plate which will give access to the lift cylinder pipe and the cylinder itself. Undo the pipe and then the cylinder which should drop down to the side of the pto housing. Put the cylinder on a very clean bench and push the piston out. Replace the seal - in the UK these can be purchased from www.charnleys.com or www.tractorspareparts.co.uk - both will send abroad. Fit new seal being careful not to damage the lip and replace the cylinder. Fill the hydraulic tank with 2 gallons of super universal 10/30 tractor oil which is also used in the engine and gearbox and all should be well. Regards John Poulter PS: buy or download the workshop manual.

AussieLeyland
Posts: 3
Joined: Wed Apr 25, 2018 1:07 pm

Re: Volcano gearbox

Post by AussieLeyland » Mon Apr 30, 2018 12:40 pm

Thanks for that. Yes, I discovered the oil bypass when I removed the three point linkage assembly.

I've just bought the tractor recently and it has had a "repair" done to the casting. I hadn't had it long enough to notice oil disappearing from the hydraulic reservoir. The ram mist have had a sudden blowout as you suggest.

The poor little thing has sat outside in the Australian weather for the past 20 years parked on a hillside uber a gum tree so the gearbox oil was badly contaminated with water. It's all changed now and sounding much happier for it.

Ley154
Posts: 70
Joined: Sun Apr 01, 2018 8:22 am
Great Britain

Re: Volcano gearbox

Post by Ley154 » Tue May 01, 2018 6:13 am

Hi again. Water gets into the box through the gear lever pivots. It is essential that you have good rubber gaiters around the levers. These may be available where you are otherwise the two companies I wrote about before will have them. John.

Nowtnew
Posts: 116
Joined: Sun Apr 01, 2018 8:49 am
Great Britain

Re: Volcano gearbox

Post by Nowtnew » Wed May 02, 2018 9:21 am

Hi

You might also have a look at the brakes. When the transmission is overfilled it gives the brake shaft oil seals a hard time and some might have got through.

Regards

AussieLeyland
Posts: 3
Joined: Wed Apr 25, 2018 1:07 pm

Re: Volcano gearbox

Post by AussieLeyland » Sat May 05, 2018 5:52 am

Yes, I'll get to the brakes next.

One side isn't working, so I'll have to pull them apart anyway.

I'm slightly distracted between the one that I have had the overfilled gearbox issue with and it's twin, a non running one that has injector issues. That one is taking up most of my attention at the moment because it is teasing me by NEARLY going, then something will break and it's back to square one again.... Yesterday the wiring caught fire :roll:

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