Talk Morgan Forums Morgan Sports Cars Morgan Plus Four, Supersport & Plus Six (CX & CXV Generation Vehicles) Safety Recall - Brakes

To me this appears to be a machined casting of inadequate design and engineering.

If I had CX, as soon as the warranty was up I would be looking for a quality replacement. I guess some enterprising specialist will be on this already.

The brake servo is high up on the bulkhead. So I guess the linkage from the pedal is complex

IMPORTANT – STOP DRIVE VEHICLE SAFETY RECALL – Morgan
Yes like other CX chassis Morgan owners I got the safety recall notice – four times to date!
While investigating our 2019 Plus Six soft brake pedal and excessive brake pedal travel problem it was discovered that the brake fluid temperature was excessively high. The source of the problem was the heating of the master cylinder due to the close proximity of the master cylinder to the exhaust manifold. I’m sure that this high temperature will be the reason for the failure of the rubber seals. My technician recommended the fitting of a heat shield between the master cylinder and the exhaust manifold.
Hence TWO years I informed our UK dealer of the problem and asked if Morgan was aware of the problem and a solution. Since then silence until today! The present situation is one that could have been avoided years ago!

This could maybe be the problem but i have a left hand drive plus four and since i have the car i have the same complain about the travel and the softness of the brake pedal. The exhaust is rightside but the master cylindre is leftside. One month after the reception of my car i bypassed my dealer and send a mail to the factory . The answer was to contact my dealer first and the plus four was very safe and the braking sufficient for the car.

I have driven 3 CX cars. Two Plus Fours & a Plud Six all had a very long travel on the brake pedal. I can't why this is heat given how close the Roadster brake servo is to the exhaust & how far away the CX one is.

I’ve always had a problem with the brake pedal, on my Plus Four Auto, put your foot on the brake pedal to start and the pedal is high, as soon as it starts it drops just over 2”.
The factory have tried a new master cylinder and booster, but to no avail, also the booster pushrod on some may not have any threadlocker on them. So the heat is not a problem for me.

That's interesting, there is a sequence of tests for a servo that exhibits the symptom of long travel on the second press, would have to look it up, but IIRC you test the difference between engine off vs on, as it could be a vacuum fault

The master cylinder on an Aero Chassis Plus 8 is barely 10cm from the catalyst... BUT it is wrapped in heat shielding material, as is the cat.
After 9 years and close to 46,000 miles the brakes are as good as ever.
So how did MMC end up with heat degradation of the master cylinder seals?
I took a look at a Plus 6 master cylinder: no branding on either side or the top.
I stand by my original statement, value engineering, made worse by poor engineering design.

I understood from one dealer the brakes are unique to Morgan.

I’ve owned a six for over a year now, third radiator, now the do not drive brake issue.
My car todate has travelled over 900 miles on the back of a low loader having fault fix, Well say fixed more bodged together buying time,
My dealer says MMC has no idea whats wrong and when a fix will come. Don’t know about everyone else but my thinking is the product is not fit for purpose and maybe time for handing back and getting a refund.??