Bleeding Sierra rear calipers

[I.Mupferit]

I think I need to bleed my braking system again after recently doing the job as I think there may still be a bit of air in there. Does the perceived wisdom say that you should wind back the pistons in the rear calipers before attempting to bleed them?

 

After trying the pedal on a couple of other 7's with the same brakes as mine at the weekend, they both felt much firmer than mine so I'm sure there is still some air in there. I have done the usual trick of pulling the handbrake on and off whilst bleeding which did release some air as did tapping the calipers and I have bled both sides of the front (big) brakes. The only thing I didn't do was wind the rear pistons back so I'm thinking this may be the problem.

 

Any thoughts?

 

Brent

 

2.3 DURATEC SV Reassuringly Expensive

R 417.39 😬

[BYKer Will]

Brent

 

Stuart faulds (great guy) at fauldsport told me the rear calipers trap air as mounted 90 degrees out from their design position.

 

I am dissapointed in my brake pedal firmness despite bleeding and pulling up the handbrake etc so will try his tip to remove from hub and blead with calipers stuck to a piece of wood 90 degrees round.

 

 

If you do sooner let us know if it works!

 

[6speedmanual]

Gunson's EasiBleed

 

 

6SpeedManual

*tongue*There's no such thing as too much BHP per Ton 😬

[I.Mupferit]

I've got the Easi-Bleed but I still think there is air in there.

 

Brent

 

2.3 DURATEC SV Reassuringly Expensive

R 417.39 😬

[h_____]

Never had this trouble on my supers car. bleeding with 2 people (no easy bleed) always seems to get a good firm pedal. End up doing it at least twice a year.

[F355GTS]

Brent

 

I've taken to taking them off in the past, putting a suitable piece of material between piston and claws (otherwise it falls out ) and then bleeding with the nipple uppermost and also changing the angle whilst bleeding

 

Another thing to check is the pads are correctly seated with the pad lug located correctly in the piston

 

 

 

Mark

[I.Mupferit]

I'll try taking them off and doing it then I think Mark. At least I can wind the pistons back as well while they are off.

 

What a right PITA to have to do it like that though. Ho hum.

 

Until I tried these 2 others with identical brakes to mine, I thought I had a firm pedal as well h but I'm not so sure it is firm enough now so it can't hurt to give it another go.

 

 

Brent

 

2.3 DURATEC SV Reassuringly Expensive

R 417.39 😬

 

Edited by - Brent Chiswick on 18 Sep 2007 09:11:50

[Paul Richards]

I recently had a problem with a poor pedal and it was down to the rear brakes. Should be no need to rewind. As others have said they can sometimes trap a bubble of air which clings to the inside of the caliper. I've not had this myself, but others have and as an alternative to taking them off, you could try tapping them with a hammer to 'dislodge' the air bubbles.

I found the problem with my brakes was that they were 'releasing' too far. In other words they were moving back a long way from the disc after pedal released. This caused a longer pedal to push them back. As F355GTS says - make sure they are seated correctly and important to make sure the stainless piece on top of the caliper is in the right place. This is a stainless channel on which the small butterfly springs on top of the pad run. There are tags on the ends of the stainless channel which are folded to mould around the caliper and should be easy to see if they have moved out of position. Worked for me.

Good luck.

 

Paul Richards

Area Representative - L.A.D.S. (Lancashire and District Sevens)

www.lads7.co.uk - now updated

Growing old is compulsory - Growing up is optional

[Molecular--Bob]

Is there any advantage in doing the bleeding while the brakes are still hot? Just wondering if this would help the air bubles out due to reduced viscosity.