Hi Folks
My 420 has a strange brake set up .I have removed the spirolux circlip and the normal circlip but I cannot get the piston assemble out,some m/cylinders I have worked on have a stop pin located on the fluid inlet that needs to be removed,but I cant find one.
But it is definitely hitting some sort of stop.any advise most welcolme.

Best Wishes Dan Gardner

 

The 420 certainly has a weird brake set up.

For all to ponder:

 

Hi Glyn
Thanks for the w/manual copy,I have read through and cannot find why the piston is still stuck in the bore,the brake booster cylinder does have the locating pin that needs to be removed.But the brake m/c is a mystery.I am torn between getting a kit or buying a new cylinder.
I see you are from Cape Town, we were there when the water restrictions were on about 3 years ago its a nice part of the world.
Thanks for the manual copy.
Best Wishes Dan Gardner

 

Presume you have extracted valve assembly 7 from the outlet port? Presume you have not got as far as damaging spring retainer 25 in your efforts to dismantle?

I'm scratching my head to understand the difficulty unseen. The manual is not helpful in this regard..

Good luck!

 

Hi Glyn
Please find 4 photos of the master cylinder.I cant see any locking device to stop the piston coming out,I have been gripping the polished end in a vice with aluminium jaws and tapping the body with a copper mallet but even using copper I am still marking the edge of the body.
.I have tried gripping it vertically and then using tyre levers,but it still wont budge.The piston moves out and then comes to a dead stop.I dont want to use heat as I will destroy all the internal seals.I am at a loss at this stage.


PS I saw the photos of your car,it is truly magnificent a real credit to your expertise,well done.

Best Wishes Dan

 

The 420 Master looks to be the same system all 4.2L E-Types used. What is confusing is there is a pin in the outlet port that must be removed on the E type cyl. I do not see it on the exploded view. If you check the outlet and there is a small pin remove it and all will spill out!

 

Photos did not attach. Thank you for your kind words.

 

E Type 4.2 Master Cylinder.
















Page here for parts above diagram No 26. (Page with arrows at bottom right hand corner) Jaguar Parts Manuals always have diagram after listing for that section) Or download & blow up with one of the photo viewers.

https://parts.jaguarlandroverclassic...ile/index.html

 

Forget numbers. Is there a retainer pin here? Or in that region? (There are a few errors in Jaguar documentation. Found a number in S Type parts manual).

 

Hi Glyn
I had to resort to using a 3mm wood chisel and cutting out the blue plastic disc,and then it finally came out it was just rusted in solid,unfortunately the polished piston got slightly marked(It was a lot softer that it looked.Due to the state of the bore I think I will exchange it for a stainless lined one($430 AUD)
I have yet to do the Booster slave(that does have a locking pin) Thanks for all your help and advise.

best Wishes Dan Gardner

 

Did you ever find a pin? I had all my cars hydraulics stainless lined & bored back to standard spec so normal jag rebuild kits can be used. Interestingly the highly accurate seamless stainless tubing used by my re-builder Summit is manufactured in Aus.

 

Hi Glyn
Never found a pin,just siezed with rust,please find photos.

Best Wishes Dan

 

Interesting. Thanks!
Kind Regards,
Glyn