Steering reservoir leak

My 1985 Landrover 90 steering reservoir leaks. This is the old metal type that looks way too big and is bolted to the inside RH of the engine bay. Clearly the lid leaks as fluid is sitting on top inside the outside lip.
I'm told by a reliable source that it's normally down to people over tightening or trying to undo it with some kind of mechanical grip and this buggers the screw lid causing it to eventually leak. HIs solution is to take that out and fit a later plastic smaller one that works much better.
Before I take out an original part, I thought I'd ask on here to see if anyone had a fix.
a) Would the smaller one work the same, maybe there was a design reason to have a 20 gallon reservoir!
b) I'd like to keep things as original as I can without being too difficult.

They pop up on ebay but I'm reluctant to buy another one that leaks.
Thoughts?

Check the inner cap for the seal. If there turn it up the other way,sometimes works

Have you over filled this ?
You can still get hold of the metal PAS resevoirs so you may be able to get a replacement cap

Hicap phill said:

Check the inner cap for the seal. If there turn it up the other way,sometimes works

Have you over filled this ?
You can still get hold of the metal PAS resevoirs so you may be able to get a replacement cap

Click to expand...

The seal is good.
It's not overfilled, I'm told the fluid washes around a lot when in use therefore it needs a good seal.
I'm thinking, because it's been 'buggered', the thread underneath does not hold shape either. If someones used grips on this (it looks that way), then the thin metal will bend on the thread too and therefore, it's all buggered.
I did not initially find a place that sells this kind of reservoir, if I could find a new one, then maybe (within reason), I'd buy a new replacement.
(Q: what is PAS?)

styleruk said:

The seal is good.
It's not overfilled, I'm told the fluid washes around a lot when in use therefore it needs a good seal.
I'm thinking, because it's been 'buggered', the thread underneath does not hold shape either. If someones used grips on this (it looks that way), then the thin metal will bend on the thread too and therefore, it's all buggered.
I did not initially find a place that sells this kind of reservoir, if I could find a new one, then maybe (within reason), I'd buy a new replacement.
(Q: what is PAS?)

Click to expand...

Power assisted steering ..

You can replace the metal for the later plastic.
These mount in same area.

Hicap phill said:

Power assisted steering ..

You can replace the metal for the later plastic.
These mount in same area.

Click to expand...

I'm told they can fit in and will probably do that, but thought I'd look into it first to keep things original, although it's not that important.

A little dig down in the design of power steering reservoirs and it seems the bigger one was used to reduce fluid overheating. I'm assuming this would be in hot countries, that said, it's a good reason to try and fix the one it has maybe.
So now I'm thinking maybe not use the smaller one if I can fix what I have.

styleruk said:

A little dig down in the design of power steering reservoirs and it seems the bigger one was used to reduce fluid overheating. I'm assuming this would be in hot countries, that said, it's a good reason to try and fix the one it has maybe.
So now I'm thinking maybe not use the smaller one if I can fix what I have.

Click to expand...

Just saw the price for a new cap… over £100

Could you try a bit of ptfe pumbers tape to see if this helps the threads seal?

Hicap phill said:

Just saw the price for a new cap… over £100

Could you try a bit of ptfe pumbers tape to see if this helps the threads seal?

Click to expand...

yup, I was thinking of trying exactly that. I may even buy the one on ebay for £25, even if it's just the cap that's knackered, it may be worth a try. Quite surprising how motor racing increase the size of the reservoir to reduce over heating. I've heard people say 'why they got such a big reservoir in the older land rovers', there may be a very good reason regarding over heating. Maybe the later pumps were designed differently, meanwhile, I think I'll endeavour to keep the original now.