410 Brake Upgrade

[David C]

Very interesting to see Roger's reply. I can understand a single experience of that sort instigating a major upgrade.

I never suffered this sort of issue but I never did much driving in the mountains. I seem to remember a report that John Bolster tried to get the brakes on a new 410 to fade but couldn't manage it.

The fade that Roger refers to with the front master cylinder bottoming out would be caused by water in the brake fluid boiling. It is really important to change fluid regularly. There are now very cheap moisture content testers available. I try to remember to test all the family's cars at least once a year.

An alarming braking experience I had in a 410 was when the entire block of friction material parted company from the pad plate. The car had been unused for some years and I think water had got in between the friction material and the back plate and then frozen.

It took about three pumps of the pedal before the back plate started scraping on the disc and enough pressure could be built up in the other brakes to stop the car.

I now replace all pads on cars new to me regardless of how much material is left.

[Roger Morrall]

Originally Posted by David C

The fade that Roger refers to with the front master cylinder bottoming out would be caused by water in the brake fluid boiling.

I’m sorry, I seem to have given the wrong impression by including my last paragraph regarding another potential fallibility of the 410s brake systems. I should also have said fail rather than fade.

I ran a maintenance schedule which was based on Bristols recommendations but rather more rigorous. This included changing out the brake fluid on a very regular basis. Pads were also new and the discs relatively new on the alpine trip

I believe the fading I experienced resulted from overheated pads and unventilated discs (the pad material just doesn’t bite if it all gets too hot) rather than boiling fluid. I don’t recall the brake pedal hitting the floor as happens if the fluid boils.

[David C]

Sorry to jump to conclusions. That's really interesting. What make of pads were you using? I always used genuine Lockheed - now Delphi - and never managed to get fade. Obviously not trying hard enough, but as mentioned I never drove anywhere with really long descents.

[AndrewA]

Thanks for all the replies - much appreciated.
Re continuing investment (Roger) I console myself with the fact that it is probably less than the annual depreciation on our modern cars and I do enjoy it as we're now at the stage - most of the time - where money spent results in improvements, rather than fixing stuff one thought was ok.
Have done many thousands of happy and swift miles throughout Europe this spring/summer, without incident so I'm very happy.
The only real issue I have with the brakes is that once it's been sat for a while, on the first push of the brakes you meet some resistance but not much happens, then you keep the pressure on and the the pedal goes to its normal position and you have normal braking. After that first push, it works perfectly. David has already suggested that first port of call is to work the piston back and forth and just have a good visual inspection.
The pedal requires quite a bit of effort, but I have no benchmark. It certainly requires one to stand on it a bit when hauling down from high speeds.
The servos were done by SLJ when I bought the car as well as overhauled callipers, discs and pads.
I did the BODA sprint at Southport and it coped well with late, hard braking with good bite.
On reflection and re-reading your replies, it seems a good idea to have a proper look at the callipers, followed by the servo - just to make sure it's all working as it should, and go from there. It's a repro servo and I've had fun and games with them in the past on other cars.
Will keep you posted. Any more thoughts, keep them coming please

[Sam410]

I find my 410 brakes quite heavy but effective. I've only ever faded them once, on a spirited drive along the A421 in Milton Keynes, where there are 12 roundabouts connected by short stretches of dual carriageway just long enough to get up to 70 or 80 before braking hard for the next roundabout.

I have however cooked them quite thoroughly in mountains before now. No fade but lots of smoking when coming to rest. I think vented discs may be an improvement.

I know one chap who took his 411 around Castle Combe with enough gusto to have the paint on the Jaguar alloys fitted visibly bubbling and boiling when he came back in, but he said the brakes still worked perfectly.