ever re-routed brake lines inside a mini...im having probs

[bmt216a]

Hello,

I am off to Mongolia in a mini in July and I am currently doing some work to it. I have re-routed the brake lines from the front to the back inside my mini using the correct size copper. That is all I have changed to the brakes side of things.

I am currently trying to bleed the brakes using the pedal and one person on a nipple starting off at the nearside drum. I have gone through 2 litres of brake fluid and still not getting a pedal. I have no leaks, I have no air coming out of the nipples. Altough after about four pumps I get pressure and the rear brakes lock up, but nothing on the front.

The brakes worked before I touched it so I know the master cylinder works

Can anyone help?

[eccles]

it might be worth cracking the unions on the master cylinder itself as there might be a bit of air trapped in there.

[Cooperman]

It could be the master cylinder. In normal use the cylinder only moves a very short way down the cylinder bore, but when you bleed the system you are pushing the cylinder and hence the seal over the ridge which forms with time and use. I've had this a couple of time.
How old is the car? Could it be the servo, I wonder, as these can be a problem as well for the same sort of reason. To have used 2 litres of fluid does indicate a fairly fundamental fault.

[bmt216a]

The car is an 87 model, no servo on it. Its only done 40k miles. COuld be the cyclinder. Might mean taking it apart and having a look.

cheers

[cooperman]

With what you are proposing to do a change of master cylinder, new wheel cylinders and a caliper rebuild could be most wise. If it were me I would change all the flexible hoses as well. Not expensive and much safer.

[cooperman]

Having just posted the above, I'm now having a little difficulty getting a decent pedal after fitting a brand new servo to my '64 'S' last night. Bled a lot of very expensive AP600 racing fluid through and still it's spongy. I've left it to settle overnight and will try again this evening. The master cylinder is fine as the pedal was right up without the servo and it's a fairly new cylinder. S**t happens!

[cooperman]

All sorted now, I bled out the rears some more and the pedal is perfect now. Dtove the 45 miles into work today in it, but with the s/c c/r drop gears I now find ear plugs are good for that sort of journey! Great to be driving it again in fully prepared spec. Just got to get it tracked at the front to complete the rebuild, then on the rollers for fine tuning.