Lagondaforum

Subject: jacks (Jackall system)

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one of my front jacks of the DB 3liter is leaking at the bottom seal. Who has already dismantled them ? They are different from the V12 ones !. I only find one thread at the bottom of the outer cylinder and so far could not get it moving even with big tools and heat.

And is there a source fot spare seals?

Subject: Re: jacks (Jackall system)

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found nice service information, MG Y seems to have used the same system as the postwar Lagonda : http://www.mgcars.org.uk/mgccy/pdf/scimag52.pdf

does not tell how to get the rustet thread moving

for spare parts I found this supplier (MG S and postwar Lagonda have the same jacks it says) and e-mailed him for info.
http://www.svwspares.co.uk. They have a huge spare parts list, the jackall is here: http://www.svwspares.co.uk/catalogue/page20.htm Includes exchange jacks for 73.50 GBP
They say they use heat to get the thread moving

here we may find more advice and contacts:
http://www.mgcars.org/mgccy/ - go to Technical Centre - Jackall Advice

Subject: Re: jacks (Jackall system)

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Hi Peter what Oil are you going to use in your Jackall?
Peter

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Subject: Re: jacks (Jackall system)

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On the mgcars.org site "Technical Centre", "Technical Advice" somebody recommends "Motor cycle fork fluid is nearest equivalent fluid nowadays - about 20 SAE"

On the V12 I have used hydraulic oil from a local supplier for machine hydraulics, where I also bought all missing connections and hoses for the V12, I will put it here if there is any specification on the can. This fluid works fine. Comparing the viscosity of my hydraulic oil with the recommendation from the MG site it seems similar.

Subject: Re: jacks (Jackall system)

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I found the specification on the can:

HLP 46 has a viscosity of 46 mm2/s (=cSt = centistokes) at 40°C,
there is also HLP 22 and lower available.

When I now think about it, the V12 jacks retract quite slowly with HLP 46. I would try lower viscosity. If the system leaks a bit, then of course it will leak a bit more too.

You will find local suppliers for these oils, on the internet search "hydraulic oil hlp 46"

Have fun with the jacks, don´t creep under the car when using them !

Subject: Re: jacks (Jackall system)

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some impression from working on one of them. It needs much heat to get the large fine threads moving after 50 years.

To remove the foot from the inner tube, I made an aluminium clamp to hold it: I bored a slightly (0.3mm) to small hole in an aluminium block on my lathe, an then cut the block in two halfs. This clamps around the end of the inner tube to hold it when turning the foot with a big tool after heating it (turbo flame) and while trying to turn, hammering on the foot !

Took me hours to find that procedure. A few scratches in the tube (from some other trials) could be filled by soldering.

Fun is to rebuilt all: first screw the fitting on the top to the screw on the end of the long return spring. Than you can use a lathe to pull the spring out and fix the foot to it. See some impressions on photos.

I will now test if the cleaning made it tight again or if I have to replace the U-seal inside. (now I will be much faster in opening and rebuilding). The U-seal has dimensions 1-1/4 x 1-3/4 x 5/8. Modern U-seals with this diameters are much less high so propbably it would need an insert to fit a modern one.To be continued...

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