Last Sunday, I attended "The Walled Towns Friendship Run" around the said walled towns in North Wales. It was a good day. However, on the way back home, on braking from 70ish mph, the car toot a violent turn right. Not at all amusing! Investigations reveal that I have the left hand calliper with a sticking piston. Both callipers have now been removed and cleaned and new seals ordered! The callipers appear to be of a later 2 1/8 inch diameter pistons from an S type. Interesting.

 

Thank God you didn't have a bad accident !

The front ones on my 340 are 2 1/8th as well.

If one was sticking, then maybe it would be a good idea to rebuild them all, or at least inspect them. At the very least, feeding new fluid though the system may also be in order.
If the car sits for long periods of time, this can happen with the hygroscopic fluid.

How old are your flexible lines in the front, some times they collapse and plug up causing what just happened ?

 

I re-built the car ten years ago with new flexies, so they should be OK. Strange to say, I took the car to my local test station and they put it through the standard MOT test. It passed on the ramps! But failed horribly on the road. I have now dismantled both front callipers and have today picked up new seals. Inside the callipers, on the wet side, there was a sticky deposit with corrosion products. Now been cleaned off and lightly polished - ready for the new seals and then fitting. I have S type front callipers on - said by my old mentor to be superior to the original type!

 

It is possible to get stainless steel versions of the original Dunlop/Girling brake cylinders, but needless to say they cost much more. I suppose it depends on how much you value your life !

SNG Barratt - The Ultimate Jaguar Parts Specialist

OK, they are expensive, and you need four for the front calipers. Even using the normal steel ones means it costs £340 for a set, with stainless steel over double that.

Might be better to fit a modern-type caliper made to bolt on the existing uprights: -

Brakes ? M&C Wilkinson

 

Either modern calipers or get the original ones sleeved with bronze (brass).
And if it's been 10 years, time to change your fluid.
Should be done every 2 years, especially if the car sits allot.

 

I now have the new seals and will fit them shortly. I use DOT 5 silicon based brake fluid which does not pick up water and does not need changing every two years. The downside is that because it does not dissolve water, any that is in, or gets into the system will, by gravity, find its way to the lowest point of the system, which means the callipers. Once there it can set about the slow corrosion process - I think!

 

Interesting why water got in there in the first place since it's not hygroscopic.
That's the whole point of silicon brake fluid.
But I guess after 10 years it's bound to happen.
I would have to check and see if there is a breather hole on the brake reservoir lid, that is the only conceivable place where water can get in.

 

I managed to get the refurbished brake callipers back on the car today. It still has a slight pull, but I am putting that down to the brake pads not sitting where they were previously. Toward the end of my trial run, they did seem to be improving. I now need to find some locking wire to secure the calliper mounting bolts. I also noted that the brake bleed nipples were of the pointed type and not the flats ended type acting onto a ball bearing. Happy days -especially as I dodged the occasional showers.