Front Caliper Replacement

[Philip Fisher]

Done my front disks and pads and noticed that the dust boot on the driver side caliper was only half attached. The part of the piston that was uncovered was corroded. I tried to clean it up the best I could and pushed it back in to the caliper (with considerable difficulty). On test driving, the brakes seem to work well enough, but there is a slight pull, so I suspect that the caliper is binding.

Anyway, ECP want about £70, so decided just to replace it. I have done a fair few jobs on my car and had the brakes apart a number of times, but never b***ered about with fluid and bleeding and stuff before. Anyone give me any advice before I find out the hard way in the dark and cold on Monday night?! I have the Haynes and am reasonably proficient at getting the pads out and caliper off the mounting bracket, but never done a brake bleed before.

Any help most appreciated.

Oh, and also, do VOC members get a discount at ECP?

Thanks all.

[bigandquick]

Hi Philip
The job is fairly straightforward, although I did do mine in the daylight! Best tool for the job is a proper brake hose clamp, alternatively adjustable mole grips with some card/thick paper to line the jaws and protect the brake pipe. Clamp the pipe off before removing the connection to the caliper and leave in place until connected to the new caliper. If you're doing the job alone, a good bit of kit is the one-man brake bleeding kit available from most accessory stores. They come with straightforward instructions. These kits are useful even if you do have some help.

[Philip Fisher]

Thanks for your thoughts and advice. Not done it yet, but have been and bought the caliper (only £55+vat) and one of those pressure bleed kits.

One other question. I have never replaced the fluid since had the car (3.5 years), so am planning on doing this now that I have the right bits of kit. How do I go about doing this? I have been told to simply flush through from the top and pump out of each caliper, rather than emptying the system and then refilling. I don't, however, know how much to pump out of each caliper. Is it possible to see when old fluid stops coming out and new fluid comes out? Should I actually pump it empty, and how much will it take to refil?

Any thoughts from anyone gratefully received.

Philip

[vjck_uk]

If your old fuid is dirty (which it probably is) then you will see a pronounced change in the colour.
Don't empty the system but just do 1 nipple at a time starting furthest away from the master cylinder and get closer with each one.

BEWARE.

Keep a very keen eye on the fluid level as you may get a bit cavalier and think 'this is a doddle' only to run the master cylinder dry which is very easy with a pressure bleeder,always on the last nipple and then you've got to do it all again.

[warthog]

If you can get hold of a decent size syringe and a piece of plastic tubing, mostly empty out the master cylinder resevoir before you start, then fill with new fluid, connect up the bleed kit and start bleeding. You'll be surprised at the amount of muck that you can draw up from the bottom of the master cylinder using this method and it saves pumping through more fluid than you need to as you start off with new fluid in the master cylinder rather than a mixture of old and new.

[Al115]

AAAAAARGH AAAAARGH AAAAAAARGH I did the rear calipers on my V70 (ex-police same as yours) and it was a b*stard to get the brake pipes off the calipers. I ended up having to hacksaw a brake pipe and replace! Definitely use a proper brake pipe spanner thing (looks like a ring spanner with a slot to fit over the pipe itself) which helps...

Good luck! :-)


Alastair

phil im not meaning to be rude, but as you appear a bit clueless about the procedure it might be advisable if possible to get a more knowledgable mate to assist you first time round there is nothing difficult in what you are doing and we all have to start somwhere but brakes are of course a critical area and not the place perhaps for someone who is not fully au fait with the procedure however if you do go ahead pressurise the master cylineder to 20psi max using a air source(spare tyre) crack the back left nipple first and wait for a clear stream of new fluid to appear when satisfied no air present and fluid is fresh move on to back right ,repeat and finally fwd left ,then right, under no circumstances as vaugan says empty the system i would have a couple of litres of new fluid available use dot 4 or 4 plus and be carefull not to overtighten the nipples

[vjck_uk]

Andy has it spot on,I don't know if it's still reccomeded but you need to get plenty of fluid through each caliper around a pint for each to make sure any water residue is flushed out.

[Chris_Rogers]

I use this method to avoid flushing the old fluid and dirt through the system.

1 Get a syringe and remove as much fluid as you can from the master cylinder reservoir, you will find the filter stops you getting much out.

2 Have a small bowl handy (large enough to hold the reservoir) and clean round the base of the reservoir.

3 Remove the screw that holds the reservoir on.

4 Carefully remove the reservoir (there is a valve on each outlet that will stop the fluid running out). Place it in the bowl to stop drips onto the paintwork. Be careful not to let dirt get into the master cylinder inlet.

5 Empty and then flush the reservoir with new fluid.

6 Reinstall the reservoir and top up with new fluid.

7 Bleed the brakes as normal.

Everyone else has said most of the points I was going to say, but I thought that mention that it's a good idea to bleed the clutch hydraulics while you're renewing the brake fluid, as they share the same fluid.