Rear brake Cylinder

[Max]

Hi ,I am asking for help

Rear left brake start loosing oil from cylinder. 

I decided to change them in both rear brakes but I am having troubles ,even if there is not air in the system(after bleeding ), cylinder won't work...

any trick?

Max

Edited November 8, 2022 by Max
grammar

[Max]

[RogerH]

Hi Max,

if you have a/any flexible hose(s) in the line then disconnect on the Master Cylinder side  and see if fluid can be pumped out.

If yes - then reconnect and disconnect on the slave side - check for fluid flow.

Work your way down the system.

 

Roger

[Max]

Thank you Roger

Done and fluid come...just look like there is not enough press ion to move the cylinder.

Front brakes works perfectly 

I am beginning to think I have bubble of air in the new cylinder

[Lebro]

A bubble of air anywhere in the system will affect all the brakes in the same way.

Bob

[Max]

Thank you Bob 

any advice?

[John Morrison]

Waht car you got Max?

John.

[Max]

hi John , an early Tr2

[stuart]

Thats a Lockheed system, adjust the brakes right up tight before trying to bleed them other wise you have an air space that you cant get rid of.

Stuart.

[Max]

Thank You Stuart

do you mean that I have to rebuilt shoes and drum before bleeding?

[Rob Salisbury]

You can't bleed a brake cylinder without the shoes and drums in place.

Cheers Rob

[stuart]

2 hours ago, Max said:

Thank You Stuart

do you mean that I have to rebuilt shoes and drum before bleeding?

Put the shoes and drum back on, wind the brakes up hard on the adjuster and then bleed.

Stuart.

[Max]

Thank you...this Sunday I will solve it

[Max]

Last doubt?the part of cylinder I rounded in the pic below, must be forced till the bottom of the hole as I mark with in the other pic?cylinder don’t have to be able to move,right?

[Lebro]

Wrong, it must be able to slide up & down, if it didn't then only one brake shoe would be moved.

Bob

[stuart]

The cylinder should be able to slide to equalize the pressure on the shoes, as long as it does slide, when you adjust the brakes so they are solid then the cylinder will be in the right place in the hole.

Stuart.

[billy l]

Hi Max, did you clamp off the flexible rear brake hose when you changed the cylinders if not the master cylinder would probably have drained off letting in lots of air, so you may have to bleed the entire system. Also the pistons inside the cylinders must be fully down to the bottom of the cylinder to insure that there is no air gap which is why it's necessary to fully wind up the adjusters. Cheers, Bill.

[Max]

On 11/11/2022 at 11:21 AM, billy l said:

Hi Max, did you clamp off the flexible rear brake hose when you changed the cylinders if not the master cylinder would probably have drained off letting in lots of air, so you may have to bleed the entire system. Also the pistons inside the cylinders must be fully down to the bottom of the cylinder to insure that there is no air gap which is why it's necessary to fully wind up the adjusters. Cheers, Bill.

Hi Bill thank you and no, i didn't clamp the hose , my plan is to change all oil system.Tomorrow will be a long day...any advice for a right and fast bleed is well accepted.

[Ralph Whitaker]

19 hours ago, Max said:

Hi Bill thank you and no, i didn't clamp the hose , my plan is to change all oil system.Tomorrow will be a long day...any advice for a right and fast bleed is well accepted.

It is a 2, or even 3 person job. You need someone pressing the brake pedal, yourself releasing the bleed nipple at the wheel end, and ideally someone keeping the reservoir topped up. Start at the cylinder furthest away from the master cylinder, usually one of the back ones, and bleed until fluid with no air bubbles is coming through. then lock off the bleed nipple and move to the next furthest away (other side of back axle) and repeat procedure. And so on until all 4 are done.

You need a length of clear pipe that you can put over the nipple so you can see if there are air bubbles coming out in the fluid, and the open end of the pipe in a jar submerged in some brake fluid so that air is not drawn back in when the brake pedal is released.

And make sure that the reservoir is not allowed to empty during the procedure otherwise you will have to start all over again.

Good luck.

Ralph