4 pot brake bleeding
11-03-2012, 06:17 PM
#3
I've found that life I needed.. It's HERE!!
this is what i bought recently and it works a treat 
http://www.ebay.co.uk/itm/Hand-held-...#ht_1951wt_905
http://www.ebay.co.uk/itm/Hand-held-...#ht_1951wt_905
11-03-2012, 06:28 PM
#4
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this is what i bought recently and it works a treat
http://www.ebay.co.uk/itm/Hand-held-...#ht_1951wt_905
http://www.ebay.co.uk/itm/Hand-held-...#ht_1951wt_905
I just thought there may be a sequence to the 4 nipples!
11-03-2012, 07:38 PM
#7
PassionFord Post Whore!!
the last 4 pot calipers I bled were on a metro 
From memory it was the 2 lower nipples at the same time, then the upper, so you could try doing the 2 lower together and then the 2 upper.
From memory it was the 2 lower nipples at the same time, then the upper, so you could try doing the 2 lower together and then the 2 upper.
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12-03-2012, 08:36 PM
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you need to force the calipers in to push out all the fluid/air from behind the caliper
will get a guide now, as i had a little issue with my ap's ( 2pots)
will get a guide now, as i had a little issue with my ap's ( 2pots)
12-03-2012, 08:43 PM
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here is some advice i was given
I would be looking at the AP calipers, the 2 pots have the joiner pipe at the bottom, therefore air gets trapped in the inner piston, you can invert each caliper turning it slowly and bleed normally or use the process below, let us know ow you get on.
You've got to be really careful not to pop the pistons too far out or they'll come out completely! Gripping the tool to the disc will prevent this.
-------------------------------------
use something like a large nut over two of the roadwheel studs on each front wheel and the normal roadwheel nuts to hold the disc firmly against the hub/drive flange. Get yourself some thing to move the front pistons in and out - I use one of these (http://www.machinema...piston-spreader). If you look at the front calipers you'll see that the fluid enters at the top of the inner piston and there is a pipe from the bottom of the inner piston to the bottom of the outer piston. The bleed nipple is at the top of the outer piston. Clearly this is a really dumb design as any air trapped in the inner piston has to be pushed to the bottom of the caliper, along the connecting pipe and into the outer piston.
What I do is remove the pads on one wheel, place the tool above around that disc and wind it so that both pistons are fully home and bleed the brake. Now unwind the tool so that it gripping the disc. Pump the brake pedal to force the pistons out to the tool (it's best to do this with an assistant to make sure it's all moving OK). Wind the tool to force only the inner piston fully home (make sure the outer piston stays fully out). Once the inner piston is fully home continue winding the tool until the outer piston is fully home. Then bleed that brake. The thinking behind this process is first to get as much air as possible out of the outer piston (tool in and both pistons fully home). Then it should have forced most of the air trapped in the inner piston back along the hose/pipe into the master cylinder (inner pistons pressed home and outer pistons fully out). With the final wind (both pistons pressed fully home) should have moved any air further along the hose/pipe towards the master cylinder and the final bleed should remove any air from the outer piston. I know that seems complicated but it beats removing the caliper!!
You've got to be really careful not to pop the pistons too far out or they'll come out completely! Gripping the tool to the disc will prevent this.
-------------------------------------
use something like a large nut over two of the roadwheel studs on each front wheel and the normal roadwheel nuts to hold the disc firmly against the hub/drive flange. Get yourself some thing to move the front pistons in and out - I use one of these (http://www.machinema...piston-spreader). If you look at the front calipers you'll see that the fluid enters at the top of the inner piston and there is a pipe from the bottom of the inner piston to the bottom of the outer piston. The bleed nipple is at the top of the outer piston. Clearly this is a really dumb design as any air trapped in the inner piston has to be pushed to the bottom of the caliper, along the connecting pipe and into the outer piston.
What I do is remove the pads on one wheel, place the tool above around that disc and wind it so that both pistons are fully home and bleed the brake. Now unwind the tool so that it gripping the disc. Pump the brake pedal to force the pistons out to the tool (it's best to do this with an assistant to make sure it's all moving OK). Wind the tool to force only the inner piston fully home (make sure the outer piston stays fully out). Once the inner piston is fully home continue winding the tool until the outer piston is fully home. Then bleed that brake. The thinking behind this process is first to get as much air as possible out of the outer piston (tool in and both pistons fully home). Then it should have forced most of the air trapped in the inner piston back along the hose/pipe into the master cylinder (inner pistons pressed home and outer pistons fully out). With the final wind (both pistons pressed fully home) should have moved any air further along the hose/pipe towards the master cylinder and the final bleed should remove any air from the outer piston. I know that seems complicated but it beats removing the caliper!!
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