Leyland 270 (1975) Hydraulics - oil refill and Main Hyd Lever issue

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Inglemere
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Leyland 270 (1975) Hydraulics - oil refill and Main Hyd Lever issue

Post by Inglemere » Sun Aug 11, 2019 9:38 pm

Hi all,
Two issues:

1. I've been told that the transmission and the rear hydraulics sump are connected so that if the transmission dip stick shows that the oil level is fine, then there is no need to add oil to the rear end. Is that true? (The operator's handbook and Workshop Manual aren'y helpful on on this, possibly because it should be obvious, but ..... !)

Due to how the loader hydraulic pipes are connected to the rear end, filling the rear end (or gear box) through the usual filler hole on the top of the back-end unit is an absolute nightmare. There is no filler hole on the top of the transmission tunnel so that is my only way of getting oil in.

I ask for two reasons:
A. because the front end load has become sluggish when lifting and
B. because obviously water has got in to the oil as it''s milky (I assume water gets in through the loader arms' seals) so I'm assuming that the oil is now not as efficient as it should be.

Can permanent damage be done by maintaining the status quo and not replacing the oil if the level is OK?

2. The Main Hydraulic Lever has developed a habit of moving itself about one inch forward of the full LIFT position and this prevents the front end from working. Pushing the knob back to LIFT solves this but is accompanied by a harsh noise and so something is unhappy in there somewhere!

Any comments / suggestions welcomed.

Cheers



Nowtnew
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Re: Leyland 270 (1975) Hydraulics - oil refill and Main Hyd Lever issue

Post by Nowtnew » Mon Aug 12, 2019 9:35 am

Hi

I expect there will be a lot of advice comes your way on this thread, but I'll try to get you started:

Yes the hydraulics/transmission and axles are fed from the same reservoir.
When the filler plug is adapted as a return for the auxiliary spool valve it does make filling more awkward.
It is not a good idea to use milky oil. The water content leads to corrosion. If you search the forum there are descriptions ( by Rick Cobley) of using an electric wash boiler (Burco) to boil the water out and thus salvage the oil. The water most likely entered around the gear levers.
The auxiliary lever will jump forward when the hydraulic pressure rises to the relief valve blow off pressure. This lever can be locked back.
Slow hydraulics can have many causes but if you are hearing relief valves blowing it suggests some form of restriction in the output side.

If you photo your hydraulic loader set up it will probably help us to help you.

Regards

Rick Cobley
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Re: Leyland 270 (1975) Hydraulics - oil refill and Main Hyd Lever issue

Post by Rick Cobley » Mon Aug 12, 2019 11:54 am

Hi, Has you loader got its own valve block or are you operating it off the quadrant?

Here is the tip to dry oil
viewtopic.php?f=14&t=19

Regards Rick Cobley

Inglemere
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New Zealand

Re: Leyland 270 (1975) Hydraulics - oil refill and Main Hyd Lever issue

Post by Inglemere » Tue Aug 13, 2019 12:29 am

Hi Rick and Nowtnew

Thanks very much for your responses. had never thought to dry the oil but at $125 for $litres, it's worth a crack!

I'm operating it off the quadrant. I worked out this morning that the lever could be locked in place but thank you anyway for pointing that out.

I'm pleased to hear that I wasn't being completely stupid re the refilling. At least I know for sure now that the back end is not running dry if the dip stick on the trans tunnel shows full. I'm not sure how the output could get an obstruction but am keen to hear suggestions.

4 pics attached (of which three might be helpful, the other just for show - apologies!).

BTW I've noticed also that the steering is really hard to work on left lock but dead easy on right lock. Reservoir and steering box are both topped up (the former while tractor on full right lock and engine running).

Cheers

Miles
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Nowtnew
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Re: Leyland 270 (1975) Hydraulics - oil refill and Main Hyd Lever issue

Post by Nowtnew » Tue Aug 13, 2019 12:25 pm

Hi again

It looks like you've misunderstood Rick's question because you have a valve block: the one with the two levers.
This is fed from the auxiliary circuit which is no doubt the source of the ambiguity.

In its simplest (standard) form the auxiliary lever is there to provide a supply for a tipping trailer. The trailer has a single acting cylinder and a single hose. Pull the lever back and it tips, push forward and it comes back down under its own weight, pushing the oil back from whence it came. Also the system is interconnected with the main relief valve so that when the trailer reaches full height the pressure increases and 'blows' the valve and causes the lever to flip forward and thus unload the hydraulics. Otherwise you'd be just straining the system at full pressure.

With your current system do you hear the relief valve blow only when a loader cylinder reaches the end of its travel or at any other time? (Aux. lever locked back).

As regards the steering the power assistance is triggered by an adjustable length turnbuckle rod which sits on top of the cylinder. Getting the length of this correct is the solution to equalised power assistance. The manual details the procedure.

Regards

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JohnP
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Re: Leyland 270 (1975) Hydraulics - oil refill and Main Hyd Lever issue

Post by JohnP » Tue Aug 13, 2019 3:18 pm

If you download the following PAS adjustment instruction you will be able to adjust your steering. Please remember that the various pins and bushes will be worn and may need replacing before you can get good steering. If it is only the turnbuckle pins that are worn you can drill the holes out a bit and fit larger pins. You will probably have to make the pins yourself.

https://www.keepandshare.com/doc/682729 ... f-78k?da=y
JVP

If it ain't bust don't fix it!

Inglemere
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Re: Leyland 270 (1975) Hydraulics - oil refill and Main Hyd Lever issue

Post by Inglemere » Thu Aug 15, 2019 4:03 am

Gentlemen JohnP and Nowtnew

You are both stars, thanks very much indeed.

May well have misunderstood Rick :-) Noise seems to have gone away now that the Main ever is locked. Noise used to happen even if loader was not at end of travel. Will check what situation is when Aux lever locked back.

Have never used back end (or front) for a tipping trailer so "don't know" re that. Have just always had a bucket on the front.
I will spend the rest of this glorious Canterbury winter day (not a cloud in the sky and a very warm 20 degs - scary for mid winter and just so you know that NZ South Island climate is thoroughly recommended) investigating further. Will be in touch with findings after the weekend.

Sounds like the cricket could do with our climate!

Cheers

Miles

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