RESTORING A CLASSIC 1970’S FRONT ENGINED V-12 FERRARI

 

The brakes now work extremely well & are now  capable of stopping the car within a reasonable distance. I have not fully tested them  but an emergency stop pulls this heavy  car up smoothly & in a straight line.


The braking system is a twin circuit hydraulic which operates on  four x  four piston calipers. The dual pipe system is fed from a tandem master cylinder mounted on the inner wing on the drivers side close to the fluid reservoir.There are ventilated discs on all four wheels with a cable operated  handbrake on a set of handbrake shoes  inside a drum disc arrangement at the rear wheels. Assistance to stop this heavy car is provided by a Bonaldi servo on the firewall close to the master cylinder & fluid reservoir.


The Bonaldi servo vacuum is fed by a reinforced tube from a vacuum  pump driven directly via a key off the  front end of the  inlet valve camshaft  on the left cylinder bank.

The braking system  was functional  but after examining the brake pipes & other components I am not sure how.

The calipers were not attached to the hubs with the correct bolts & three of them were bolted in place with a threaded bolt & string of 7 or 8 washers. The brake fluid that I drained from the system was like dirty water & clearly  had not been changed for many years.The pads were almost down to the metal backing  & I am glad I took it  really easy on my drive home.

The ATE  calipers were in a poor state  & required a total rebuild. Overhaul kits & new caliper pistons are readily available from ATE brake equipment specialists in the UK. The calipers were completely dismantled & the external & non-functional surfaces bead blasted. All fluid passages & piston bores were occluded prior to electroless nickel plating the units.These are the four completely overhauled calipers prior to refitting . A complete overhaul of the whole system was needed as I was taking no chances with a near two ton 150mph motor car. 

The  brake pipes were so badly  corroded they required replacement and  an off the shelf set was not available.. I made a new set of pipes of copper nickel alloy using a specialist pipe flaring tool & a pipe bender.Tighter curves around suitably size tool sockets. Each  brake was removed & labelled  & a new replacement was made. Replacing the  pipes in the engine bay with no engine in place was  relatively simple.

Replacing the two long brake pipes from the master cylinder to the rear which travelled the length of the car in the sill beneath the driver side was a difficult task. Removing the original pipe after attaching  a length of flexible wire so it would be possible to pull the new pipes through.The narrow channel also contained the fuel return breather hose so threading the brake pipes  front to back was tight squeeze.

This is the top section of the handbrake lever assembly which operates a pair of handbrake shoes on a special disc/drum  assembly by a single cable running between both rear wheels. The existing system was completely seized  so  it was surprising that a car with a totally defective handbrake was able to achieve an MOT standard. After reassembly the handbrake is fully able to reach the requires level but it is not the most efficient arrangement.

The rear brake pressure limiters have clearly seen better days. They are positioned well out of  in the chassis close to the differential & are not in view at all. The outer case of one unit was broken & the limiter was  held on by the brake pipes alone ¬ bolted in place.There are no user serviceable parts in these ATE limiters  but I  pleasantly  surprised to source two  new units from Ferrari UK.

The brake master cylinder was removed, stripped down &all seals were replaced as the bore & piston was in excellent condition with no visible score marks

A classic  car that stands around for a significant period of time should have the fluid changed regularly as it is hygroscopic & absorbs much water over time.

The state of the brake system components & the very old brake fluid was a real let down & I do not believe the system was working anywhere near capacity. An expert garage supposedly maintaining this car had left the braking system almost untouched over many years .It appeared that their service was limited to  regular oil changes & not that much else.

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