While driving my '68 FHC, the brakes seemed to lock on. No warning. Just pedal went hard and brakes didn't release. Made it home and put car on stands. All four tires seemed to have brakes "dragging" but more noticeable on the front. Any ideas?

Kirk Phillips
"Carmen" - '68 FHC

Submitted by georgejones123… on Fri, 10/07/2005 - 11:41

Kirk,

I had a similar experience on my Mk2 where all of a sudden the brakes applied without warning. It turnd out to be a leaky brake booster where a vacuum leak allowed atmospheric air pressure to leak in and apply the brakes. After I replaced the booster--no more problem.

George Jones

Private Restorer.66' 3.8 Mark 2,67' Ser. 1 FHC "E"

Submitted by NC19-03320J on Fri, 10/07/2005 - 08:57

Kirt, Besides what George pointed out It's possible for the lines to collapse and still look alright. If they're old it sure wouldn't hurt to replace them with the proper hoses, no auto parts gas line stuff.
Bob

Submitted by ksphillips@pro… on Fri, 10/07/2005 - 07:48

George:

When you say check all the vac lines, I presume I am looking for any disconnects, splits, leaks, etc. Anything else to look for?

Kirk Phillips
"Carmen" - '68 FHC

Submitted by SE98-32482CJ on Fri, 10/07/2005 - 07:44

First thing to check is ALL of the vac. lines to the brake master and slave (booster). Good Luck. George Camp

Submitted by rbrand@grtnw.com on Fri, 10/07/2005 - 02:59

I had a similar problem after rebuilding the brakes in my XK120 when I used silicone fluid. I guess it expands with heat more than other fluids to the point that the expansion applied the brakes. After everything cooled off it was fine again. I went back to regular fluid and it has been fine for the last 15 years. 1951 XK 120 OTS RHD; 1963 E-Type FHC; 1984 XJ6 VDP