Rear Brake Pipes

[dmiller]

Evening all!

Todays job was to replace the rear wheel cyclinders as they are leaking a bit and the brakes are spongy, and kwickfit rounded the bleed nipples last time the car was in. Not that I can prove it of course...

So car up on jacks, wheel off, polythene over the top of the fluid etc - all going well - until I managed to round off the brake pipe nuts (after ranting about how crap the kwickfit guy was I did more damage myself, karma eh?). However on closer inspection the brake pipe is rusted really badly anyway so its not the end of the world and the nuts holding the brake pipe to the brake hose turn ok so I reckon I can fix it by replacing the rear brake pipes from the hose to the cylinder and replacing the cylinder.

First question - does this sound ok?

Second question - what nuts do I need to secure the brake pipe to the brake hose and the rear cylinder? I think its M10x3/16 and I just need the Male ones for both ends? (Like the ones here: http://www.jhmbuttco.com/acatalog/Shop_ ... s_130.html)

Third question - is there anywhere online you can buy preshaped pipes?

Fourth question - is there a better place to buy car parts local to me (Kilsyth, Glasgow) than Eurocar parts or generally on the internet?

Thanks for anyhelp you can offer!

[dmiller]

Oh a fifth question just hit me - are the ends double flare or single flare? I cant get the end at the caliper to check...

Thanks!

[dmiller]

Ok so incase anyone else finds this post on google with the same questiosn heres some stuff I found out doing the job on saturday.

All in it took me 4.5 hours including a 20 minute test drive.

First of all my wheel cylinders were single bolt ones, I have a 2000 corsa b - some of the earlier ones had two bolts so check that when your buying them.

Tools needed:
Brake union spanner
Bleed nipple spanner
Torque wrench
Hammer
Pipe flaring kit
Pipe cutter
M10x3/16 male union nuts
3/16" OD brake pipe
Two new brake cylinders
Grease
Rag
Plus gas / shock spray / similar.
One man bleeding kit.
Brake fluid.
Beer.

Normal selection of sockets (25mm, 17mm, 10mm)

Do the right hand side first as thats first in the bleed order for the car.

Put in gear and chock the front wheels.
Open the bonnet, take the lid off the brake fluid resiviour and screw it back down over a section of polythene (like a bin bag) to form a seal.
Handbrake off.
Loosen the right hand wheel nuts, jack up the right hand side, take the wheel off.
Spray the brake pipe unions just now to give the spray time to work.
Remove the hub nut cover, take the split pin out, remove the hub nut. Catch the outside wheel bearing. Place the bearing on the rag to stop stuff getting into them.
Take the drum off, you might need to pull the handbrake cable away from the wheel to release the tension. The hammer might be needed here if its well stuck... Often I need to put the wheel back on and use it as gentle leverage to pop the drum off. Careful you dont pull the shoes off the drum.
Remove the top spring and pull the shoes away from the cylinders at the top. No need to take the shoes out totally.
Get the brake pipe and cut off a foot or so.
Flare one end of the brake pipe to a single (trumpet) flare. Place a union nut on it. Bash the other end flat, fold it over, bash it flat and do the same one more time.
Undo the connector from the rear brake pipe to the brake hose, some brake fluid will leak out. Fit the section of pipe with the squashed end onto it to help seal it and keep dust / water etc out.
At this point I pushed the end of the brake pipe into my bleeding kit and squeezed the cylinder a few times to get the fluid out the parts you are replacing, saves a bit of mess.
Ideally you would remove the brake pipe from the cylinder here. I couldnt as mine was well rusted and rounded.
Remove the bolt from the rear of the drum holding the cylinder on. Mine was a 10mm.
Encourage the cyclinder through to the front of the brake, gently, with a hammer.
I was able to walk the brake pipe through the hole with the cyclinder intact to use as a template for the old pipe.
Fit the new brake cylinder.
Put the spring back on the brakes and check the self adjuster is in position.
Grease the wheel bearings and refit the drum. I always grease the wheel bearings when I disturb them.
Cut off a few feet of brake pipe, flare one end (single flare) and put a union nut on it. Put on a second one for the other end but dont flare it yet. Put it on now so you dont forget it!
Fit the brake pipe to the cylinder - tighten it up to just past finger tight.
Start to shape the brake pipe. Its easy to do by hand. Key things here are to follow the old ones path (hold the old pipe next to it) hit the brake pipe clips on the chassis (my corsa has two sets on each clip so if one broke the other was ok) and keep the brake pipe straight as it comes out of the caliper for an an inch or so. Dont let it rub on anything.
Once you have it run ok cut it down to size, make sure and allow for the amount of pipe thats going into the union at the hose.
Make sure the union nut is already on it, flare it and check its shape and its not kinked.
Remove the bit of pipe you fitted with the squashed end. Fit the new pipe.
Tighten up the connectors - you are looking to squeeze the copper into a seal but not jam them tight.
Open the new bleed nipple and connect the bleeding kit.
Open the brake fluid cap in the engine bay.
Press the brake pedal 4 or 5 times. Add more brake fluid. Check that the fluid coming out is free of bubbles. Always check you have enough fluid in the resivour.
Check for any leaks.
Seal the bleed nipples.
Get your assistant (or wife) to press the brake pedal a few times and keep the pressure on. Check for leaks.
Put the wheel back on.
Lower the car.

Do the left hand side in the same way - the only complication is the exhaust might be the way on this side a bit - you should have enough room.

Test drive and check alls ok.

Put the keys in a safe place and crack open the beer to celebrate job done

David.