Rear brake shoes & cylinder

[Connect93]

Hi. I have a 2004 transit connect, 1.8 di currently with 143.000 miles. I have an issue with the slave cylinder, rear left. I have had to change drums and shoes, upon inspection of the cylinder I’ve decided to replace it with a new one. Borg&beck type, when I bleed the brakes it seems to be forcing the oil out through the cylinder seals when I pump the brake, I must note that it only forces the oil out on one pump of the brake and not a continuous stream. I’ve attempted this on three brand new cylinders all with the same result, with the first two completely bursting the rubber seal and the last one pushing the cylinder rubber seal and spring right out of the cylinder housing, also the adjuster refuses to stay in place when operating the brakes, I’m not sure if this is causing a pressure build up or a lack of pressure strictly speaking. Brakes are spongy when being operated and the emergency brake light is constantly lit when off. Any advice would be much appreciated. Please ask for more detail and info if needed. I know mabey I should call a mechanic which I have, he can’t look at the van for a few days. I’m hoping I get some advice or mabey an idea of what might be causing this so I can rectify the problem myself.

Thanks!

[motorman116]

The only thing that I can think of is.....

Your not bleeding the wheel cylinder without the shoes fixed in place / the brake drum fitted (after the shoes have been adjusted to the drums) If this is the case, then it will do this all the time.

[Connect93]

That’s the only thing I haven’t tried to do. I was assuming the shoes needed to be in place when bleeding so as the cylinder can balance the right amount of pressure, never the less I’ll give that a go, just a thought, could the servo be sending too much oil to one side? On the mot report from the last owner I can see the van has had a higher percentage balance of breaking efficiency on the left compared to the right.

Thanks!!

[dumper]

The last reply is no telling you to try bled it with shoes and drums off you have to have the brakes completely assembled and adjusted

[motorman116]

The last reply is no telling you to try bled it with shoes and drums off you have to have the brakes completely assembled and adjusted

Exactly, the only reason that I posted that, is in the post is was said that....... "with the first two completely bursting the rubber seal and the last one pushing the cylinder rubber seal and spring right out of the cylinder housing, also the adjuster refuses to stay in place when operating the brakes" which makes me think that the brakes aren't fully assembled and adjusted, with the drum in place, when bleeding the cylinder.

[motorman116]

On the mot report from the last owner I can see the van has had a higher percentage balance of breaking efficiency on the left compared to the right.

Braking performance better on 1 side to the other could be a number of things causing that, from incorrectly adjusted shoes, to just having 1 wheel cylinder replaced on 1 side, when there was a problem, or the brake hasn't been bleed properly on the weak side, or the shoes have been slightly contaminated on the weak side when a wheel cylinder leak before, even if the backing plates where the shoes meet up with them, if they are corroded, and the shoes aren't able to move freely, then even this can cause the problem

[dumper]

Sounds right to me the only outher thing may be wrong or bad batch of cylinders as you say motorman if drums on and adjusted right there is no way pistons can come out 9AA