One of my jampots is leaking...

Information relating to the Matchless G80 or AJS Model 18 500cc Heavyweight.
195318s
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Joined: Wed Aug 20, 2014 7:27 pm
Location: Hertfordshire

One of my jampots is leaking...

Post by 195318s »

Hello everyone

I've noticed a small amount of oil has leaked from one of the jampots on my 1953 18s and I was wondering if anyone has any tips or gems of wisdom before I start investigating the cause.

I've had the bike for 3 years and have done about a thousand miles in that time. The handling seems fine and I've not noticed any change - and certainly not the 'very lively action' that the owners manual says is evidence of shortage of oil. So I presume this is either a recent small leak or a very small leak that has been accumulating for some time without me noticing.

I'm hoping the leak is due to the bottom pivot lug not being sufficiently tight. My planned first step is to remove the unit from the bike, remove the pivot lug, check/top up with SAE 20 oil (to 'a trifle under 3 fl ozs' as the owners manual advises so delightfully) then tighten up and fit back on the bike to see if that has done the trick.

If anyone has any advice/tips I'd be very grateful to hear.

Many thanks

John
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dave16mct
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Re: One of my jampots is leaking...

Post by dave16mct »

You could also put a new fibre washer in while you've got the collar off.
Dave.
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ajscomboman
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Re: One of my jampots is leaking...

Post by ajscomboman »

dave16mct wrote:You could also put a new fibre washer in while you've got the collar off.
Dave.
And use some PTFE thread tape when reassembling as the new fibre washers are harder than originals and don't compress as much which can allow a bit of seepage.
195318s
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Location: Hertfordshire

Re: One of my jampots is leaking...

Post by 195318s »

Dave and ajscomboman - thanks very much for your quick and helpful replies. I'll certainly replace the fibre washer and use some PTFE tape.

Cheers

John
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Janet
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Re: One of my jampots is leaking...

Post by Janet »

If you end up having to dismantle and rebuild the offending unit, there's a funny article here called Jampot Overhaul by W Jordan http://www.jampot.com/article_read.asp?id=337 telling all the stages you'll go through. :lol:

BTW, it is very informative.
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ajscomboman
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Re: One of my jampots is leaking...

Post by ajscomboman »

Janet wrote:If you end up having to dismantle and rebuild the offending unit, there's a funny article here called Jampot Overhaul by W Jordan http://www.jampot.com/article_read.asp?id=337 telling all the stages you'll go through. :lol:

BTW, it is very informative.
I'd forgotten about that one, although tongue in cheek some of it does ring true! :rofl:

I made a holding tool from maple when I overhauled all my sets and it made the job a doddle. :beer:
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Pharisee
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Re: One of my jampots is leaking...

Post by Pharisee »

By sheer co-incidence, I reconditioned my 'Jampots' today. I took them apart, replaced the top oil seal and swapped out the plastic bushes for machined bronze items. The 'O' ring in the top mounting and the two fibre washers in the bottom mount were also replaced as were the leather washers. I also smeared a little Hylomar gasket sealer on the bottom thread before I screwed the clevis on. I poured in 85ml of SAE20 fork oil before screwing it on.
Getting them apart and putting them together again can be problematic so I cobbled together a 'fixture' to compress the springs.

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I'm from the Fens.... Gimme six.
195318s
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Joined: Wed Aug 20, 2014 7:27 pm
Location: Hertfordshire

Re: One of my jampots is leaking...

Post by 195318s »

Janet - thanks v much for that funny article. Hee hee and it makes the point - proceed with care!

Pharisee - yes, what a happy coincidence and thanks very much for your advice and sharing the pics of your handiwork.

Cheers all

John
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Group Leader
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Re: One of my jampots is leaking...

Post by Group Leader »

They are very interesting photographs Pharisee. I too will be venturing "into the Jampots" come the winter maintenance programme!

Alan
1953 AJS 16MS, 1939 BSA 250 and a 1/3 scale Sopwith Triplane but that's another story ..... :lol:
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Re: One of my jampots is leaking...

Post by SPRIDDLER »

Two excellent illustrated strip and rebuild guides here from Christians Archive:

http://archives.jampot.dk/technical/Sus ... around.pdf

http://archives.jampot.dk/technical/Sus ... ampots.pdf
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