Mud-club

Vehicle & Technical => Defender => Topic started by: Saffy on October 21, 2012, 20:44:06

Title: brakes crap after caliper replacement
Post by: Saffy on October 21, 2012, 20:44:06
Replaced the rear calipers on the 110 week or so ago......... the 5 years of squeaky brakes gone..... bliss.  Trouble is the brake feel crapola! Having to double pump and no confidence. System is bleed through many a time and over half litre of fluid just in case. Servo vacuum is there from the pump - no idea if servo itself is working - guess i could try without pipe attached?.

My thoughts are that I used the old 3/4 worn pads, and now that the pistons are free to go back into calipers (unlike the old set) there is a lot more travel before pads hit disc. The brings me to 2nd thought... wondering if the disc are warped and knocking the pads back. Or maybe the wheel bearings are loose and doing the same (though I didn't notice any play in bearings when fitting wheels).

anything other suggestions?
Title: Re: brakes crap after caliper replacement
Post by: lambert on October 21, 2012, 21:16:05
You have bled them in the right order and done the fronts too? Have you checked front bearings too or just rear ones? If rotors were warped you ought to feel in in the pedal.
Title: Re: brakes crap after caliper replacement
Post by: Boddle on October 22, 2012, 13:09:59
How did you bleed them?
Pumping pedal or
Pressure bleeding (using something like this http://www.screwfix.com/p/eezibleed-brake-bleeding-kit/33881?cm_mmc=Google-_-Product%20Listing%20Ads-_-Sales%20Tracking-_-sales%20tracking%20url&gclid=COqG6dzKlLMCFanItAod3GAAog) can be bought from halfords.

most Land-Rovers need Pressure bleeding

Changing the calipers may well have a knock on effect on the master cylinder, May worth looking at that
Title: Re: brakes crap after caliper replacement
Post by: Welshbreed on October 22, 2012, 18:32:33
Also you want to bleed in order of (pipe) distance from the master cylinder. Start with the furthest corner and then work towards the shorter pipes
Title: Re: brakes crap after caliper replacement
Post by: Saffy on October 22, 2012, 19:19:48
Bleed by pedal pump with assistant first, then pressure bled. Did the correct corners in order (I think). Will have another go the weekend and check for other issues.

the truck originally had a trailer air brake system fitted by LRSV and that is plumbed off the brake line to an actuator (handbrake also had a double cable which went to actuator). The airbrake system are long gone but that actuator is still there - wondering if it is playing up now, I will need to remove it and its brake line and cap off the T piece to make sure.
Title: Re: brakes crap after caliper replacement
Post by: trecfive on October 25, 2012, 14:33:36
If you are fitting 3/4 worn pads,wedge the pistons back in the caliper to make sure no air is trapped behind the piston. With you saying you have to pump the brakes twice to get a peddle.
Having to double pump and no confidence.
Title: Re: brakes crap after caliper replacement
Post by: Saffy on October 25, 2012, 18:31:13
<thumbs up> sounds reasonable - will do.
Title: Re: brakes crap after caliper replacement
Post by: trecfive on November 09, 2012, 18:33:12
Did it work Saffy ?
Title: Re: brakes crap after caliper replacement
Post by: Saffy on November 09, 2012, 20:01:42
Must admit I have not had a play yet - I will report back as soon as.
Title: Re: brakes crap after caliper replacement
Post by: landyman37 on November 27, 2012, 23:00:25
The way I done mine was remove calliper s and pads leaving the pipes on turn calliper upside down wedge piston then bleed refit calliper then all done repeat other side fronts seemed to bleed ok

Phil
Title: Re: brakes crap after caliper replacement
Post by: Range Rover Blues on March 23, 2013, 20:22:53
Sometimes I find they improve if you bleed them again once you've used them, air can get trapped inside calliper pistons or in kinks in the pipes.  Also with them being new you can bleed the piston/calliper by pushing the piston back in wit the bleed nipple open.

When I ran my Cavalier I HAD to bleed the brakes like that whenever I changed the pads, for some reason the brakes went spongy if I didn't :undecided:

But if you've got used to seized pistons then TBH you will hate the feel of new callipers, until the seals start to harden you will get a lot of piston pull-back giving you a long pedal when you next apply the brake.
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