HELP bleeding brakes please

Simmo · tinkerer Joined: 05 Oct 2001 Posts: 58

Ive just finished rebuilding my TE Gemmi, and its all ready to go except i can't get the brakes working. Ive replaced the rear wheel cylinders an front calipers with items i know are working, but i cant get the rear brakes to bleed - ie no fluid (or even air bubbles!!) will come out at all -
There is plenty of new fluid, and i tried bleeding the front brakes first (which worked) but i still can't get any fluid thoruogh the back.

ive also tried bleeding form the brake line union over the diff to no avail,

Has anyone got any ideas before i pull out the master cylinder, brake bias valve and replace the rear brake lines??

P.S. there are no obvios leaks or kinks anywhere in the brake lines

Cheers Simmo.

Racegem · backyard mechanic Joined: 30 Jan 2002 Posts: 987

Do you get any pedal pressure at all?

Simmo · tinkerer Joined: 05 Oct 2001 Posts: 58

yeah i get some, but with the car running, and brakes boosted there is fuck all pressure (i assume air in the line is being compressed, cause i cant find any leaks).

any ideas??

GasGem · backyard mechanic Joined: 05 Nov 2001 Posts: 755

you may have to bleed the master cylinder first, use some rags and catch container just crack the line. only should need to do the rear line the master cylinder. then try bleading the system,

as the master cylinder will not push fluid if it is full of air,

cheers
Eggy

Simmo · tinkerer Joined: 05 Oct 2001 Posts: 58

cheers mate ill give it a try.

Simmo · tinkerer Joined: 05 Oct 2001 Posts: 58

on closer inspection of the master cylinder, the piston for the back brakes appears to be seized. Ive got another master cylinder lying round thats in good nick so ill chuck that in, and maybe change the booster as well.

Thanks for your hepl fella's

Simmo.

doomboy_666 · tinkerer Joined: 25 Apr 2002 Posts: 206

yeah it's usually always the master cylinder. My brakes kept seizing up, and i replaced heapsa stuff b4 the master, but it was the master in the end. I was spuin.

Racegem · backyard mechanic Joined: 30 Jan 2002 Posts: 987

The first brake bled should always be the furtherest from the m/cyl. So in a Geminis case, rear passengers first, then rear drivers, front passengers, then front drivers. Otherwise you'll be pushing air past a point you've already bled.
When you've finished, remove the brake light warning light switch from the centre of the proportioning valve and re-fit it. This resets the piston in the valve so the light works when it should.

Yonnee.