Early Dunlop S type 1967

[RoyN]

Hi
First a thank you for assistance under the heading of clutch.
I deviated so much into breaks I thought I should start a new thread.
Slowly renewing the brakes on the above. Currently working on front calipers. After 28 years in storage I was advised to use a lot of wd40 and to consider applying heat. A 24" tommy bar did the trick.
The pistons seem solid so I have ordered a cheap master cylinder to use as a hydraulic pump ...comments welcome.
Dot 4 v Dot 5. I see this subject has been debated in the distant past, but not recently. As I will replace the whole system and would prefer to go the Dot 5 route. Does modern thing suggest this will be ok, or am I going to suffer with rubber swelling?
Finally. Servo. Is a diy recon feasable?
Any advise or comments welcome.
Roy

[Martec]

I've already commented on the Dunlop brakes, but just a bit more, when I tried to buy the Dunlop piston/ cylinders cheaper I ended up phoning the USA and found that they were made in Japan and shipped to USA (20 years ago). The problem with the original Dunlop units are that the seal is a disc of rubber on the end of the piston, if the muck seal at the top gets holed then the cylinder corrodes and is either SS sleeved or scrapped. Modern units have the 'O' ring seal (square section) at the top of the cylinder so often suffer from the chrome on the pistons lifting (cheaper to replace).

The 3 pot girling calipers will need the 420 uprights to be able to fit them, but there are aftermarket calipers that are made to fit the MkII/S type? unright.

If your servo is the lockheed servo then the seals don't take kindly to silcon fluid (mine swelled up and jammed it on), Dot 3, 4 ,5 is OK. I started using Dot 5 then but it was suggested that Dot 5 has a higher boiling point for racing and for cruising it was a waste of money over the dot 4 (I used Dot 4 and replace it every 2 years).

I stripped and fitted new seals to my old Lockheed servo which lasted about 10 -12 years but was then heavily corroded in the vacuum cylinder. I gave it to a recommended refurbisher over in Lancashire, the first one locked the brakes on at an MOT!!!! the replacement now farts due to the new air valve.

When I rebuilt mine I took great care to set the central spindle to the exact distance, the refurbishers didn't think that was important!! next time I'll rebuild my own and again accurately reset the spindle.

Best of luck.
Brian