Technical Minimal brake pedal travel - only one brake engaging

[Avspotter]

Hi all,

Back again, and stumped again with my 1988 Panda 1000CL.

Having recently bled the brake fluid, the front left calliper seized up - I replaced this and its accompanying hose and now it’s buggered.
The brake pedal is VERY firm (max 3 inches travel) and only the new brake is engaging. This new calliper piston also isn’t withdrawing all the way as it remains engaged once pressure is removed, like it’s miscalibrated itself.

I’ve gone around and tested the bleed nipples on the other brakes to see what the pressure distribution around the circuit is like - when I stamp on the brake pedal, fluid dribbles out of the 3 old brake nipples but jets out of the new calliper. The pedal doesn’t sink to the floor when the bleed nipple for the 3 old brakes is open, as one would expect when the circuit pressure is relieved.

When driving I basically only have braking action in the front left (new) brake leading to very slow deceleration and the wheel locking up (taking all the force). I've since removed the metal pipes for the rear and right-side brakes from the unions in the master cylinder and then re-attached them just to inspect the cylinder fluid flow - it leaves the cylinder as one would expect and doing this has generated several more inches of brake travel (potentially due to air I've just introduced to the system, but doesn't feel like it...)

If anyone has any ideas why the fluid is not going to the rest of the circuit that would be hugely appreciated!

The photos show the new calliper and brake line.
Cheers
H

 

[Dragon Man]

that sounds like its a master cylinder fault.. i would not even chance it and just out right replace it. i managed to buy a replacement from ebay for £7.99!
chances are its as old as the car anyway and i can tell you, 34 feels old as its as old as i am!
im not sure if the 1000cl had a brake vacuum servo assist.. i would also check to see if thats ok if you have one fit. you'll know its got one if the master cylinder is under the spare wheel.
i sadly lost a close family member to failed brakes on a motorcycle bought from a dealer under 3 years old..
for what they cost on our little cars just replace if you suspect faults.

 

[Avspotter]

that sounds like its a master cylinder fault.. i would not even chance it and just out right replace it. i managed to buy a replacement from ebay for £7.99!
chances are its as old as the car anyway and i can tell you, 34 feels old as its as old as i am!
im not sure if the 1000cl had a brake vacuum servo assist.. i would also check to see if thats ok if you have one fit. you'll know its got one if the master cylinder is under the spare wheel.
i sadly lost a close family member to failed brakes on a motorcycle bought from a dealer under 3 years old..
for what they cost on our little cars just replace if you suspect faults.

Thanks for the response - so I’ve checked and it’s not the master cylinder - I’ve removed the pipes from the unions and in pushing the pedal, it goes all the way to floor and gives a nice jet of fluid out of the cylinder. Yet when the pipes are connected, the pedal is firm even with the bleed nipples on the brakes undone.

Don’t suppose there could be some sort of blockage somewhere that is messing with the whole system - maybe a bad flexi hose?

Strange that its 3 wheels not just the rear circuit or front brake circuit!

 

[porta]

Have you checked the flexis to all the wheels as one could be collapsed internally?

 

[Avspotter]

Found it was the right flexi hose - pretty staggered at the effect it's had and the difficulty in diagnosing it! Undid the top of the hose and fluid ran freely, but when the hose was reattached and the calliper removed, the brake was firm again. Thanks for the help guys

 

[The Panda Nut]

I hope you have taken the BIG hint your car has delivered and changed all the flexis and also that you do the other calper as well. Doing in ones is I feel not money saved but a timed ticket to the next failure. We have a 20 year old Seat and I had all the flexis changed afyter 17 years and felt extreme guilty for leaving it that long. 20 years is more than enough. I have expereinced brake failure twice in my many years of driving. Once in central London as a passenger when my mum was driving - I used the handbrake to stop the car which was only doing 20mph. (flexi pipe failure at about 12 years old) Then second time was at 70mph and miraculaously was late at night in the middle of no where and I stopped it with gears and hand brake just as it slid into a ditch at a T junction. That was NOT an experience I would wish on anyone. (failed welded repair on a brake back plate) I had a 17 mile walk to get help and get towed home, but no damage done. Moral of my story, is never skimp on brakes or steering parts. Replace things after a sensible time span and only use new top quality parts. Do the work on both sides at the same time. Do it once and save money in the longer term. It might just be a life saver.