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1958 G3L oil pipes

Posted: Mon Aug 08, 2016 1:46 am
by pouchy750
I'm rebuilding a friends bike, that I didn't take apart, so keep getting stumped on a few things.
On the engine, which is the supply & return lines? The bottom banjo nut is bigger than the top one. Top supply, bottom return?
Looking at the oil tank from the right side, which way round do the oil pipes go? There are 2 tubes, one behind each other. Front supply, back return?
Thanks for your help.

Re: 1958 G3L oil pipes

Posted: Mon Aug 08, 2016 7:22 am
by Stuoyb
With the oil tank empty looking at the two pipes on the bottom, one of them is connected directly to the bottom of the tank (rear) this is the feed (use a torch if you can't see in normal light). the other tube (front) extends the full height inside the tank with a small outlet hole that you can see from the filler aperture - this is the return.
From memory(someone may prove me wrong) the feed on the crankcase is the lower of the holes using the union nut.

Re: 1958 G3L oil pipes

Posted: Wed Aug 10, 2016 7:57 pm
by Fenlander
The attached snippit from a maintenance manual should help.
Note the threads in the crankcase are BSP

Re: 1958 G3L oil pipes

Posted: Wed Aug 10, 2016 8:49 pm
by clive
Also note which way up the pump pin 5 goes, the recessed end into the body. Put it the other way round and the oil supply and return will be significantly reduced.

Re: 1958 G3L oil pipes

Posted: Mon Nov 16, 2020 7:57 pm
by Dave Holmes
Hello all - I have a 1953 G3LS which is leaking very badly from the oil supply and scavenge lines where they enter and exit the crankcase. Can the whole unit be removed (after draining the sump!)?

Re: 1958 G3L oil pipes

Posted: Mon Nov 16, 2020 9:01 pm
by SPRIDDLER
Not exactly sure what you mean by 'the whole unit' but once the gland nuts at the crankcase have been undone the pipes should just pull out/away.
Strictly speaking you don't need to drain the sump as it isn't really a sump. The return side of the pump has a greater capacity than the supply so there will normally only be a small amount of oil at the base of the crankcase unless the bike has been unused for a while in which case oil from the oil tank will probably have seeped past the pump and into the crankcase. Obviously you'll need to drain the oil tank.

Be very careful with the spanners on those gland nuts as the crankcase casting at that point is easily cracked leading to oil leaks.
To make removal a bit easier the correct bolt behind the nuts (see photo) should have a reduced thickness head.
At crankcase. Bolt (640x365).jpg
As you are not showing as a member you may not 'have permission' to be able to see the above photo so I'll repeat the photo here but from my remote hosting site.

Image

Re: 1958 G3L oil pipes

Posted: Sun Dec 06, 2020 12:07 pm
by SPRIDDLER
Dave Holmes wrote:Hello all - I have a 1953 G3LS which is leaking very badly from the oil supply and scavenge lines where they enter and exit the crankcase. Can the whole unit be removed (after draining the sump!)?
pouchy750 wrote: On the engine, which is the supply & return lines?
Looking at the oil tank from the right side, which way round do the oil pipes go?
Did any of this help you two guys ?
;)

Re: 1958 G3L oil pipes

Posted: Sun Dec 06, 2020 2:45 pm
by clive
given that Pouchy750 wrote in 2016 I doubt you will get a reply! David Holmes might though.

Re: 1958 G3L oil pipes

Posted: Sun Dec 06, 2020 6:21 pm
by Group Leader
clive wrote:given that Pouchy750 wrote in 2016 I doubt you will get a reply! David Holmes might though.
And he lasted visited the forum on: Thu Aug 18, 2016 5:28 pm you could well be right Clive!

Alan

Re: 1958 G3L oil pipes

Posted: Sun Dec 06, 2020 7:49 pm
by SPRIDDLER
clive wrote:given that Pouchy750 wrote in 2016 I doubt you will get a reply! David Holmes might though.
:oops: Don't confuse me with the facts. I'm old.

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