Brakes on Austin A40 Sport

[Cujo]

Have a 1953 Austin A40 Sport Convertible that is experiencing a strange brake issue (car is all original and well maintained. After driving for a period of time (30 minutes or more) the brakes start to over heat and drag (especially the fronts). Now normally this would heat the drum and cause less braking ability but in this case the brakes actually start to bind to the point of making the car undriveable until the brakes cool to air temp.

Thoughts

Thank you in advance

 

[PhilW]

I've found it common on the Jags, but it's usually only one front wheel or both rears. The Jag problem is the old flexable rubber lines at each front wheel or one at the rear. The inner liner rubber goes bad and acts as a one way valve inside the hose, keeping the brakes on. Your problem sounds like the master is not letting the pressure build-up from brake heat go back to the brake can. Are all 4 wheels locking up?

Only my guess.

Phil.

 

[aeronca65t]

Yes....I agree with Phil. I've seen flexible brake hoses do that too.
Also, be sure the brakes are adjusted too tight; they shouldn't be dragging all the time.
I *think* that car has mechanical back brakes (with hydraulic on the front only....right?)

 

[Cujo]

Definitely not dragging (adjustment is correct). Brakes are hydraulic all around. I will check the hoses as I had never heard of that before - thank you for the feedback.

 

[Deleted member 8987]

When this happens, place a rag around the fitting on the pressure side of the barake master, and crack the fitting.
If it goes "poof" and the brakes release, the issue is at the master cylinder, either pushrod too tight, vent not working, or just a bad master.
That will eliminate the rest of the system.
Fast, easy.

 

[DrEntropy]

Yup,

With both fronts doing the same thing it is less likely to be the flex lines. Tho if they're over a decade old, I'd be for replacing them all anyway, as an abundance of caution. Seen too many of 'em turn into one-way valves lately.

 

[Cujo]

Thanks everyone - of course the car has not done it again since I posted but I will check at the master next time it occurs. Just brought her back from the Father's Day British car picnic in Beacon Hill Park here in Victoria. Only one of her kind in Western Canada as far as I know and she received lots of attention - though I still might have traded her for one of the 2 beautiful XK 120's if the offer had been made