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Bleeding brakes! SIMPLE CURE
Posted: Sat Feb 25, 2006 3:12 pm
by tim siggs
Just overhauled front calipers and fitted new pads, have bled rears and then fronts but still have long pedal, but it does pump up and holds pressure. can anybody suggest what to try next.

Cheers Tim.
Posted: Sat Feb 25, 2006 3:50 pm
by Bob_Salmon
Bleed them again, and again - The only way.
Bob
Posted: Sat Feb 25, 2006 4:02 pm
by tim siggs
Thanks Bob but I really have bled and bled them, even had the local garage use their compressed air bleeding machine on it.

Cheers Tim
Posted: Sat Feb 25, 2006 4:52 pm
by impmad2000
Sorry if this is obvious, but, are the calipers on the correct side ? The bleed nipple needs to be at the top in order to let all the air out properly. Had this with another car (Not Porsche) would not bleed till I got them on the correct sides

The calipers were seemingly identical to each other, the only thing that made them handed was the position of the bleed nipple !
Cheers
Tim
Posted: Sat Feb 25, 2006 5:11 pm
by tim siggs
Thanks Tim. yes I had to double check but yes the nipples are at the top. Do you think it could be the master cylinder, it's a 19mm dual circuit type but I'm not losing any fluid.

Cheers Tim
Posted: Sat Feb 25, 2006 6:26 pm
by bjmullan
Take it for a good run and use the brakes hard and then re-bleed them again.
Posted: Sat Feb 25, 2006 6:40 pm
by impmad2000
tim siggs wrote:Do you think it could be the master cylinder, it's a 19mm dual circuit type but I'm not losing any fluid.

Cheers Tim
It is possible... bleeding the brakes could have taken the seals over a ridge in the MC, and damaged the seals. If only the "Inner" seal is damaged, would this cause this ?? I don't know for sure though.
Not sure I'd recommend driving the car anywhere if the brakes aren't right though Brendan
Tim
Posted: Sat Feb 25, 2006 8:25 pm
by tim siggs
Thanks Brendan and Tim, I have taken it for a good run and apart from a long pumpable pedal the car pulls up nice and squ and did improve, but I shall overhall the MC on Monday, I'll keep you posted. Cheers Tim
Posted: Sat Feb 25, 2006 9:50 pm
by Barry
Hi Tim, I had exactly the same thing: went through four litres (

) of fluid, I kid you not. After the first litre or so there was no real evidence of air, perhaps just the odd tiny bubble, but still very spongy on the pedal.
It turned out that the pads were not meeting the discs perfectly evenly, and they were twisting ever so slightly as the pedal went on. Re-checked everything, and in the end just drove it. First journey was for the MoT, which it passed fine with brake measurements being very good. After a couple of hundred miles the pedal firmed up nicely.
If it still feels a bit soft after your drive, just get someone to push the pedal whilst you watch the pads: I'd be interested to see if you've had the same thing

.
Posted: Sun Feb 26, 2006 12:06 am
by tim siggs
Cheers Barry, after what you say I think I'll run it for a bit (with caution) before I go down the master cylinder route. Cheers Tim. PS read your post welcoming Phil, if you ever won't to rekindle the memory of your gulf blue 911 I would value your opinion of mine. just PM me and we can make a meet.
Posted: Sun Feb 26, 2006 2:11 pm
by Barry

Just noticed you're only in the next county: when the weather warms up a bit, and the sun comes out I'd like to meet up: thank you.
Posted: Mon Feb 27, 2006 1:05 pm
by tim siggs
The problem was the brake pedal was long but did pump up and hold pressure. It was suggested that I tried the following, pump pedal till firm and hold down, then wedge it in that position, in my case overnight. I used a piece of timber from the steering wheel to front of seat and another from pedal to the first piece (if that makes sense). Removed wood in morning and pedal was back to normal. Hope this is of use if you have the same problem. Cheers Tim

Posted: Mon Feb 27, 2006 2:18 pm
by Barry
Interesting: trying to work out what's happening there

. Still it's worked, so useful tip

.
Posted: Mon Feb 27, 2006 5:01 pm
by tim siggs
Barry, I think what happens is the constant pressure squares the cylinders and pads to disc.