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Replacing Knuckle joints - wet suspension
Posted: Sat Dec 13, 2014 9:18 pm
by haynes
How do you go about this, i mean do you have to let the suspenison down by 'authorosed dealer' as per the Haynes Manual. Or can you let the rear wheel hang to relax the front enough to get the joint out?
If anyone knows of any suitable online guides Id be pleased to see the links.
Re: Replacing Knuckle joints - wet suspension
Posted: Sat Dec 13, 2014 10:04 pm
by Dr S
I think I've done this with it pumped up, probably with the top ball joint popped to get enough droop. However I wouldn't do it now. I use a grease gun with a schrader valve connector on it as a pump. It can't vacuum the system but trimming it is no trouble. Cost me 80 quid from the back of practical classics years ago. You could probably make one for half that.
I'll try and post pictures tommorow.
Re: Replacing Knuckle joints - wet suspension
Posted: Sun Dec 14, 2014 12:45 pm
by 'S'-type
I don’t think it’s advisable/possible without depressurising. Even with the hub detached the arm is still under pressure though you might be able to try some levering with a pry bar but I think reseating would be difficult.
These links from MG sites may be of use if you wanted to go down the route of DIY pump up
http://www.mgfcar.de/pump/
I made one like this
http://www.mgfregister.org/forum/viewto ... 795#p34795
But I notice there’s one on ebay cheaper than you could make yourself Here:
http://www.ebay.co.uk/itm/NEW-Hydragas- ... 27f2f2ba22
but I think you would still need to buy a low loss connector
Low loss connectors here
http://www.prosol.co.uk/tools_and_equip ... r_p418.php
and here
http://www.lasaero.com/site/products/ar ... =N04HO75SL
This also looks interesting at £160:
http://www.jellydeal.co.uk/rothenberger ... g-pump.htm
Most of these won’t do the vacuum though.
There’s a Churchill on ebay currently at £225 (about to end)
http://www.ebay.co.uk/itm/Churchill-Hyd ... 3f41ef08cc
Or failing these I suppose, use a friendly local guy that offers the hydro pump-up service! You can drive a short distance on the bump stops. I don't know what the going rate is, but I've been ripped-off on this a few times down the years.
Re: Replacing Knuckle joints - wet suspension
Posted: Sun Dec 14, 2014 2:04 pm
by Dr S
Mines just like the eBay one, it's quite functional.
I'm not certain about using it from a dry system, like a I currently have ( new displacers and new lines ).
Plan to either borrow a Churchill or try and bleed out most of the air at the front bulkhead Union. So fill the pipe and burp the rear using a trolly jack and fill the fronts down the flex pipes. That only leaves a short length of pipe with air in it instead of fluid.
More news after the 21st / 22ns when we've tried it!
Nick
Re: Replacing Knuckle joints - wet suspension
Posted: Sun Dec 14, 2014 2:26 pm
by 'S'-type
Yes I haven't pumped up an empty system.
Good luck
Let us know how it goes
from another Nick
Re: Replacing Knuckle joints - wet suspension
Posted: Sun Dec 14, 2014 6:50 pm
by spoon.450
I need to do this on my mk2 S in the near future and was going to put a spacer on the knuckle before refitting to raise the front end slightly. I imagine it will be difficult getting the old knuckles out of the displacer ( after 45 years ) while the displacer is still in the subframe, even with the system de-pressurised. Perhaps the displacer has to be removed ?? Any info. / suggestions will be appreciated.
Thanks
Dave
Re: Replacing Knuckle joints - wet suspension
Posted: Sun Dec 14, 2014 6:58 pm
by Dr S
Getting the knuckles out can be tricky. If you try and twist it you risk tearing the rubber. Needs a little reaction to get them to shift. Ball joint fork between the knuckle and the inner circle bit will shift it with a good sharp shock.
Nick
Re: Replacing Knuckle joints - wet suspension
Posted: Sun Dec 14, 2014 6:59 pm
by Dr S
With the top arm out, then turn the displacer a few degrees (maybe 45) and it'll drop out. Just feed the hose through and it'll drop down dead easy.
Re: Replacing Knuckle joints - wet suspension
Posted: Mon Dec 22, 2014 10:54 pm
by Dr S
Blew mine up from empty today. Worked well. Full write up on how in my build thread on redshed the mk2 tommorowish!
Easy system to work with!
Re: Replacing Knuckle joints - wet suspension
Posted: Mon Dec 22, 2014 11:39 pm
by ianh1968
Dr S wrote:I use a grease gun with a schrader valve connector on it as a pump.
<SNIP>You could probably make one for half that. (£80)
My Dad's "Hydrolastic Pump" was made out of a bog standard
brake master cylinder and various bits of scrap metal...
The cylinder was mounted on a piece of box tube, had a pivot
and a handle about 18" long. There were various bits of pipe
to feed the cylinder and transfer the fluid to the schraeder.
It took a bit of pumping because of the small piston, but it did
do the job.
We used water and antifreeze.
It was a '66 Super Delux (I think) and the plan was to convert it to
dry suspension, but still be able to revert to wet if that did not prove
possible.
From what I can remember, it was just a case of bending the displacer
mounting lugs outwards to enable standard spring/rubbers to go in.
The front top arms also had slightly different centres from the spindle
to ball to swivel hole. Again, if I remember correctly, the hydro top
arms gave a slightly harder ride when used in a dry setup.
Ian
Re: Replacing Knuckle joints - wet suspension
Posted: Tue Dec 23, 2014 3:06 am
by minimans
The last of my stash it's hard to find in the States......................
DSC04783.JPG