Brake pedal is 'sucked' to the floor
Discussion
Dear all, I have a snag with my brakes that I have never experienced before, and I was wondering if anyone out there could give me a few pointers.....
Basically, the pedal feels over-servoed, as if it is being sucked to the floor. When I press it gently, the pedal sinks away from my foot in a way it never used to, and also does not return fully up, (ie brakes off) when I release the brakes completely. The return spring is present and correct, and the snag appeared overnight, so I don't think that a gradual stretching of the spring is the root cause. Still, you never know.....
Car is an S3C with 86k, with the separate fluid reservoir and mstr cylinder.
I'm baffled. I shall try replacing the brake fluid first off, but if you have seen this problem before please let us know. Ta.
Chin up
Basically, the pedal feels over-servoed, as if it is being sucked to the floor. When I press it gently, the pedal sinks away from my foot in a way it never used to, and also does not return fully up, (ie brakes off) when I release the brakes completely. The return spring is present and correct, and the snag appeared overnight, so I don't think that a gradual stretching of the spring is the root cause. Still, you never know.....
Car is an S3C with 86k, with the separate fluid reservoir and mstr cylinder.
I'm baffled. I shall try replacing the brake fluid first off, but if you have seen this problem before please let us know. Ta.
Chin up
quote:
Dear all, I have a snag with my brakes that I have never experienced before, and I was wondering if anyone out there could give me a few pointers.....
Basically, the pedal feels over-servoed, as if it is being sucked to the floor. When I press it gently, the pedal sinks away from my foot in a way it never used to, and also does not return fully up, (ie brakes off) when I release the brakes completely. The return spring is present and correct, and the snag appeared overnight, so I don't think that a gradual stretching of the spring is the root cause. Still, you never know.....
Car is an S3C with 86k, with the separate fluid reservoir and mstr cylinder.
I'm baffled. I shall try replacing the brake fluid first off, but if you have seen this problem before please let us know. Ta.
Chin up
I wonder if one of your brake circuits has failed?
I had these symptoms on a Scimitar and agree with the responses. I found I could release the brakes by briefly stamping on the brake pedal.
I dismantled the master cylinder, extracted the worn parts and then found out it was not a user-serviceable component. Had to buy a replacement unit - DOH!
I dismantled the master cylinder, extracted the worn parts and then found out it was not a user-serviceable component. Had to buy a replacement unit - DOH!
Gents,
many thanks for your replies. I had a sneaking suspicion that the master cylinder was to blame.....
I won't be driving the car for a while as I am away, but on my return I will be getting my hands dirty before enjoying the sunshine that has typically arrived as my car breaks!!! (Think of me you lot, eh!)
Just one more question, then. Does anyone know where to get new mstr clinders, or what car they are from? I had a look in the bible but didn't find the answer, but I was in a bit of a hurry....
Disregard that one fellas. A bit of digging through past discussions has led me to the Saab 9000 answer.
Again, thanks for the replies everyone. I'll be away for about 2 weeks, so please don't think I am being rude if I don't acknowledge any replies in the meantime!
Cheers, chin up.
>> Edited by chin up on Saturday 1st June 18:54
many thanks for your replies. I had a sneaking suspicion that the master cylinder was to blame.....
I won't be driving the car for a while as I am away, but on my return I will be getting my hands dirty before enjoying the sunshine that has typically arrived as my car breaks!!! (Think of me you lot, eh!)
Just one more question, then. Does anyone know where to get new mstr clinders, or what car they are from? I had a look in the bible but didn't find the answer, but I was in a bit of a hurry....
Disregard that one fellas. A bit of digging through past discussions has led me to the Saab 9000 answer.
Again, thanks for the replies everyone. I'll be away for about 2 weeks, so please don't think I am being rude if I don't acknowledge any replies in the meantime!
Cheers, chin up.
>> Edited by chin up on Saturday 1st June 18:54
I had a similar problem last summer in my S3 which resulted in the pedal sinking to the floor and the brakes binding on, not what you want on a dual carrage way at speed. After looking at every thing I found both rear cyclinders were weeping (although just passing an MOT) and the master cyclinder was week on its return action.
After dismantling the master cyclinder there was a ridge inside, probably caused by lack of use and the spring has lost some of its original energy. I got a new master cyclinder from David Gerald (about £100) courier over night. The rear cyclinders are about £15 each being only Sierra parts.
Good Luck.
After dismantling the master cyclinder there was a ridge inside, probably caused by lack of use and the spring has lost some of its original energy. I got a new master cyclinder from David Gerald (about £100) courier over night. The rear cyclinders are about £15 each being only Sierra parts.
Good Luck.
Thanks Nick for the reply. What you say sounds familiar. Basically, I have resigned myself to a new master cylinder for starters, and while I am there I think I will go for new drilled discs (240 mm) with ebc greenstuff pads and possibly reconditioned calipers. (I am feeling flush!) Obviously I will give the backs a going over to check all is well.
Why ebc and not ferodo? Well, the car is used everyday, and I plan on doing 1 or 2 trackdays a year post the brake rebuild, so proper fastroad/trackday pads are not really needed. Also, ebc are cheaper
Thanks again, chin up.
Why ebc and not ferodo? Well, the car is used everyday, and I plan on doing 1 or 2 trackdays a year post the brake rebuild, so proper fastroad/trackday pads are not really needed. Also, ebc are cheaper
Thanks again, chin up.
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