Sticking Sprint Front Brakes

[CharlieA]

I've searched for past suggestions for my problem with no success so far. Brakes apply just fine, car stops as desired etc. However, front brakes do not release (except very slightly over span of several minutes.) Car is '72 Sprint and it does not have any servo, although does have Federal dual master and split hydraulics. I can release fully by removing wheels and using large pliers to force pads/pistons back away from disc. With wife pumping pedal and me pushing back alternatley I can ease the stickiness only slightly. What mechanism normally helps withdraw the pistons after application? Only thing I can think of is stiffness of rubber boot, but can't imagine that being enough.
Thanks for anyone's thoughts/advice.

[ppnelan]

Sounds like it needs the calipers overhauling with new seals & maybe new pistons. It is the flexibility of the seals (not the rubber dust boots) that pulls the pistons back.

Matthew

[types26/36]

Think I would start by jacking up the car wheel free and checking which wheels are binding.......is it all?.....the fronts/rears or just one?
Could it be a hydraulic hose collapsing internally ?
Have you tried bleeding and replacing the brake fluid?
I dont know the federal master cyl. but I would think it has a vent in the cap, is this vent clear? after these checks it would give you an idea as to where to start and if the calipers need attention.

[Frank Howard]

Charlie,

It's been my experience that as the pads wear down, the pistons must come out of the bores further. Once the pistons reach the point where they are out too far, they can tilt and as a result, jam in the bore. If the pads are worn at all, I suggest you go down to your local parts dealer, pick up a set of Triumph Spitfire pads and install them. This may solve your problem.

[CharlieA]

Thanks Frank, Brian & Matthew. Sounds like Matthew may be correct, as it is fronts only, pads, hoses and fluids are relatively new. Vent in the cap is open. I had pistons replaced 3-4 years ago and drive less than a tankfull of gas a year. (Guess I should change that, as I know things work better the more you drive!) Winters in upstate NY not good environment. Adding to problem is garage is pretty damp.

Anyone comment on the difficulty of installing new pistons, seals & dust boot?

[1964 S1]

The job is not all that difficult, it becomes a question of how valuable your time is. I'd check the usual suspects for the best price (on reliably sourced rebuilt units) and go from there. Those Triumph connections are sometimes most helpful.

[1964 S1]

I just re-read the thread. Less than a tank full of miles per year ! EEGADS, drive the heck outta the thing ten times more than that. And a damp garage in upstate New York?! Of course your brakes are sticking, they're like owning a race horse, I suggest selling it to someone who will drive it.

[pereirac]

My local Triumph supplier had exchange units for ?50 each which seemed easier than buying pistons, seals etc. A bit more expensive but a lot less hassle and no problem about scored bores. The Spprint front brakes are standard Triumph (Spitfire?) units.

Carl

[CharlieA]

Thanks Carl. I was thinking somewhat along those same lines.
Charlie