Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Brakes fade in heat.

I have posted on this before. When my 2014 Plus 4 gets hot for example on a hot sunny day and I am driving for a couple of hours, the brakes diminish significantly. The pedal nears the floor and the braking response is not good to the extent I am concerned about taking the car out. I have had the car serviced and brake fluid changed. I had DOT 4 fluid replaced with DOT 4. The brakes in cold weather are fine. Should I be looking at changing the fluid to DOT 5.1? Does this affect anything else? Do you think this would assist with my issues?

Thanks

Not necessarily a fluid issue.

May be sticking caliper/calipers or rear cylinders causing excess heat to build up and the brake fluid to boil. Get them checked first

If you have ruled that out, then maybe consider a change to a fast road pad. Something like DS2500

Arwyn

Arwyn is correct - much more likely to be a sticking brake. I suggest a 30 minute drive and then check disk / drum temperatures.

Does the handbrake relase fully?
Do you think it possible that you rest you clutch foot against arm of the brake?

Cant think that another fluid change, sticking slave cylinders or new brake pads are going to affect the pedal going to the floor.My money would be on poor seals in the master cylinder, allowing fluid to flow by the operating piston when under pressure.

Think again....OP said it does it when hot but not when cold. Dodgy seals in the master cylinder would not be heat related

Arwyn

Maybe scraping the barrel, but I was thinking fluid getting thinner and seals getting a bit floppy with heat.If the car has been (properly) serviced as noted, then one might expect working of slaves and callipers would have been inspected as a routine.
Be interesting to hear the outcome.

My first guess is sticking caliper(s). I had that on my Plus 8 out on a run. AA got it sorted for a return home but only a temp fix. I had a HiSpec upgrade on and the seals in one caliper were the problem. New seal kit and bingo. Back to normal. Changed the fluid at the same time.

Thanks for replies. I have it booked in for the 27th so I will see what the garage can find and update the thread. Handbrake works fine I have asked for all brakes to be checked and to have a look at the master brake cylinder. Lets see what comes back.

Ask them to check the flexi hoses whilst they are at

You could have one breaking down internally causing the brakes to stick on

Arwyn