I have an issue with brake pedal not holding pressure. On first press the pedal is firm , and travel is fine - but when keeping a constant pressure on the pedal it slowly and gradually descends over about 30 seconds until it is literally on the floor and braking is lost. A release and pump returns the pedal back to normal. The car had been standing for a considerable time unused prior to my purchase but recently it did have some attention to brakes as the flexible hoses and couplings are brand-new. (advised by seller).
I was just going to try another brake bleed and hope that fixes the problem as it may not have been done quite right, but I noticed in the workshop manual there are suggestions it could be Master Cylinder cups? ... I hope not but the pressure is being lost somewhere. I cant see any signs of leakage.
Brake Pedal recessing
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Re: Brake Pedal recessing
Worth trying another bleed, but it sounds like the master cylinder needs replacing to me.
Re: Brake Pedal recessing
I had this exact same problem when I bought my car and it turned out to be a failed master cylinder. I wouldn't drive it until you've had it sorted.
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- Minor Legend
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Re: Brake Pedal recessing
Almost certainly it is a master cylinder problem - either worn seals or bore corrosion or both. The lack of sealing allows a small internal fluid bleed past the seal, which in turn allows the pedal to descend slowly to the floor. A quick pump and the cycle starts all over again!
As above, replace the master cylinder before using the car.
As above, replace the master cylinder before using the car.
Richard
Re: Brake Pedal recessing
As above - unless there is a slave cylinder leak - needs a new master cylinder.
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- Minor Friendly
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Re: Brake Pedal recessing
Removed the MB Cylinder a couple of days ago ... and are currently checking all brake hubs / seals / wheel cylinders and so far so good. Looks like the brake shoes and flexi's have been recently replaced , but whoever - decided not to do the Mcylinder...
The MC is being chrome sleeved and rekitted ..... thanks again for all the feedback that was certainly the problem ...
The MC is being chrome sleeved and rekitted ..... thanks again for all the feedback that was certainly the problem ...