Sudden Brake Failure

[FOX5D]

Hi chaps

This single circuit stuff is far too dangerous to my mind. In addition to the obvious dangers to health of brake failure, we spend loads of time and money on our beloved Elans to enjoy the performance and power. Yet the majority of Elan owners run single circuit brakes! Me included at present!

"Scary" doesn't really describe the feeling when you drive up to a busy t junction, put your foot on the brake pedal and feel your foot hit the floor! Brake master cylinder failure!

Also a friend had to drive his S4 into a hedge to stop his car, after a similar failure where his brake fluid suddenly disappeared into the can of his Girling servo.

I have a 66 S3 and 70 S4 both with lockheed servos that work very well, but I feel so nervous about the single circuit thing that I will probably install tandem m/cs and dispense with the servos-shame, they are both very new!

That's my sixpennuth for what its worth.

Cheers

Jim

[stugilmour]

Just thinking along the lies of Jims post, if my dual circuit Federal system failed like Mark describes on one circuit, perhaps I would not be able to get the other booster to work if the pedal was truly jammed with no pedal travel at the master cylinder. Scary failure for sure.

Just a thought.

[Elanintheforest]

I went to see a mate at the weekend who spent over 600 hours over the first few months of this year restoring the bodywork of his Climax Elite, and had painted it to perfection. You know what's coming!

On the 2nd trip out driving this little beauty he came across a line of cars stopped at the traffic lights, hit the brake and nothing happened. He hit an earth bank at about 40mph and destroyed the front of the car, subframe and all. Luckily he fixes Elites and the insurance paid out very quickly, but the incident has shaken the confidence somewhat. The culprit was a failure of the master cylinder, which was overhauled in the last 12 months.

My E type recently had the pedal go to the floor as well, though luckily I was just getting it out of the garage! The entire braking system of that car was overhauled 5 years ago.

I'm really starting to wonder about the viability of overhauling these somewhat vital bits, or should we be replacing with brand new parts? The integrity of 'repro' parts has been called into question many times, and although I only use Girling seals, I'm wondering if they are built to the same specification as the original? But I guess that the real culprit is the age of the master cylinder / servo etc., as it's bound to have some score marks in the bores that we can't see after 40 or more years, and that would promote rapid deterioration of the seals.

New master cylinders in the future, methinks!

Mark

[GrUmPyBoDgEr]

I wholeheartedly agree with replacing these vital parts with new "quality" parts.
Visual inspection of the bores is just not good enough to check for minor scores or scratches; the "shineyness" which can be observed in any bore is an optical illusion which can lead the unwary into believing everything is O.K.
Even when fitting new seals of known "good quality" it is possible to cause damage to those most delicate seal lips or unknowingly introducing some form of contaminate that could produce a leak.
What price "life" against the cost of a new cylinder, just don't save the pennies at the wrong end.

FWIW
John

[Galwaylotus]

I had one of those moments when I cut a rear brake hose (it was rubbing on a disc) when driving my first Elan many years ago. Didn't hit anything but on my current S3, when I had servo problems with the brakes locked on, I got rid of the servo, installed a tandem master cylinder (same bore), Aeroquip hoses and GreenStuff pads on the front. No problems now!

[Elanintheforest]

I was just scanning in a copy of the Service Voucher book for another topic and spotted this timely reminder!!

I wonder just how many of us change the washers, seals and hoses in the entire system every 3 years, the fluid every 18 months or just before a long journey?!!

Mark

[rgh0]

I do this routine 3 year change in caliper seals and change the fluid each year in my competition Elan because I work the brakes really really hard. But it is probably overkill in a normal road going Elan unless you do the same and work the brakes very hard.

However you cant leave seals for 20 years and change the fluid every 10 years and expect no problem even in a road car. I find a stainless liner in the old master cylinders is the most relaible way to fix and better than some of the new dodgy stuff available.

cheers
Rohan

[The Old Italian]

I'm really starting to wonder about the viability of overhauling these somewhat vital bits, or should we be replacing with brand new parts? The integrity of 'repro' parts has been called into question many times, and although I only use Girling seals, I'm wondering if they are built to the same specification as the original?

First statement .... I'm not an Elan owner.
Second statement .... I have had brake failure 4 times in my '69 Alfa.

The first time was never properly diagnosed (multiple reasons, including maybe a shorting brake light switch?) so the whole system was overhauled.

The second time was due to a (13 month old) duff 'repro' master cylinder;
there are rumours that the cylinders and the washers were/are a mix of Imperial and Metric sizes.

The third time was the servo failing as I approached Quarry at Castle Combe (the pedal went rock hard)!
After that I dumped the servo, and fitted a (smaller bore) Girling master cylinder instead of a 'repro' cylinder;
which brings me to the question: WHY in a car as light as an Elan do you need a servo at all?
My car weighs 1000kg and is fine with no servo.

I change my fluid (RBF 600) every year and the car never stands for too long without use.

[FOX5D]

I get the impression that many Elan owners would agree with your sentiment about not needing a servo. From my perspective I would prefer to have a servo as it just makes things easier particularly when you switch from using a modern car.

However, if I am faced with a choice of having a simple tandem system where I would at least have some brakes with a brake failure, or having single circuit with a servo and only a handbrake , then out with the servo!

I think that if you want a degree of safety with old technology then it is probably best to keep the number of components (that could let you down) to a minimum. I have been convinced by other Elan owners on this forum. Long may it continue.

Cheers

Jim

[alaric]

Hi. My clutch master cylinder played the straight to the floor trick. I stripped it to find that there was some dirt on the o ring seal that stops the fluid coming back into the reservoir when you put your foot on the pedal. The dirt was from rust on the return spring... Single point of failure there that's not nice really.

I've looked before but still not managed to ID a tandem mastere cylinder. Any votes as to which one should be fitted to a +2?

Sean.

[Galwaylotus]

Hi. My clutch master cylinder played the straight to the floor trick. I stripped it to find that there was some dirt on the o ring seal that stops the fluid coming back into the reservoir when you put your foot on the pedal. The dirt was from rust on the return spring... Single point of failure there that's not nice really.

I've looked before but still not managed to ID a tandem mastere cylinder. Any votes as to which one should be fitted to a +2?

Sean.

Contact Caterham Cars. They have one for the Seven that has the same bore as my S3 (0.7 inches I think). Bolts right in. I put a remote reservoir on it so it's not under the carbs. It's aa AP Racing unit.

[alaric]

Ok I'll have a look. Thanks. I don't think I'm going to bother with the servo - it's in pieces anyway and would be single circuit, so a tandem master with no servo should be neat. My old mini had an extra unit that I think blocked off the leaking circuit if there was a pressure differential. I think there's something like this on the tandem elans too.

Regards.

Sean.

[Galwaylotus]

I'm certainly satisfied with my brakes without the servo. "Adding lightness" and one less point of failure.

[lotocone]

Reading this topic last summer made me think about my tandem master cylinder and now I find I have a big problem. The MC probably has just 10-12,000 miles of use, but it is 25+ years old. It was a new replacement back then.

Anyway, this week I decided to remove it and look at the bore. When I was disconnecting the pushrod from the brake pedal, I noticed a couple drops of brake fluid where the pushrod goes through the rubber boot. A few minutes later I noticed a lot of brake fluid under the car. Both halves of the MC reservoir were about 2/3rds empty! I didn't expect that much leakage at all. I thought maybe I lost a few ounces, but I guess it leaked out slowly over the last few months while the car was stored for winter.
One other point, the pedal was hard when I last drove the car. At least the fluid didn't get onto the chassis paint.

The bore had one small rough spot and I decided to send out the MC to have the bore sleeved in brass which it is harder than the aluminum bore. The place I sent it to (Sierra Specialty in California) seems to know their stuff, so I'm going to have them rebuild it too.

Will also rebuild the front calipers soon even though they appear to be okay. The rear ones were done recently due to a stuck piston.

So, based on my experience I'd recommend checking out any master cylinder that you have questions about.