Problem setting brakes

[tarynus]

Hi everyone!
I finally managed to fit my brake system without any leaks, I think I did the bleeding alright, can't see any bubbles anymore, but I'm still having a soft pedal.
I believe the reason for this is my rear brakes are not set correctly but I can't figure out why.
I tried setting them by turning the self adjusting ratchet wheel, but even with it spread to the max the brake shoes barely touch the drum.
I've only tried setting the rear brakes on one side, but I believe the problem while be the same on the other side.
Does any one have a clue what the problem is?

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[Mad Mart]

Have you got a pic of the whole setup so we can see what's what?

[tarynus]

Sure

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brakes 3.jpg (105.66 KiB) Viewed 1410 times

[Mad Mart]

I can't see anything out of place. If you've turned the adjusters out fully you shouldn't even be able to get the drum on.

[MIG Wielder]

I agree. It all looks good. Which leaves the brake drum. Can you measure the inside diameter of the drum on the shiny running surface. Even a steel ruler measurement should be good enough for this. The maximum drum diameter dimension is cast into the front face of the drum
Tony.

[tarynus]

I did the adjusment again on both sides and get a hard pedal half way down.
I measured 22.9 and 23 cm on the drums and found different sets of numbers
4 DA 229976
2 DA 229976

I believe DA stands for diameter, and would it be 22.99 cm?

Hence meaning I would need new drums?
Still if that is the case is it not strange that if I'm on the very limit, having new brake shoes should kind of counter balance the use of the drums and give a correct pedal?

[80Sprint]

Are the drums smooth all the way across the inner surface or do you have a big lip on the outer edge ?

[soe8m]

Measure the outer distance of the linings. If this is way out the shoes are wrong. Powertune from india isn't the best in replacement parts. You can also check if the metal part is the same compared with the old shoes. The best is to use NOS sets from mintex or ap or QH. These do fit and have plenty of asbestos.

Jeroen

[Jon Tilson]

Do the cylinders slide okay in the back plates?

Are you sure the system is bled properly?

Its adjusted right when a slight movement of the handbrake lever locks the drum. Pump the brakes and work
the handbrake linkage vigouroulsy to centre the shoes and try adjusting it again. It should self adjust but I can always
get a few more clicks by hand than the self adjuster.

Jonners

[tarynus]

Here's a pic of the drum, there is some sign of wear on the left one, is that the big lip you mentionned?

brakedrum.png (420.14 KiB) Viewed 1305 times

Here's is how i did, maybe i did something wrong during the process:
After bleeding (started from rear up to the MC, and did the rear again, apparently better for tandem brakes? Anyway no signs of air left)

I adjusted each brake by hand (havent connected the handbrake yet), then pumped on the brakes, then back to adjusting, pumping etc.
One thing I did find odd is that everytime after adjusting I would turn the drum to hear the linings scraping on it, but after a turn or 2 much less surface would then be in contact with the drum ( maybe that is a normal thing though)

How can I check if the cylinders slide ok? I did put some grease on them,should i be able to slide then by hand, or do i want to get someone to step on the brakes and take a look?

Any tips for checking the system is bled properly ( is the cylinder piston moving with a slight step on the brake good enough to be sure?)

[Jon Tilson]

With the shoes all off, which you probably dont want to do again, you can slide the cylinder quite easilly by hand.

Sometimes the cylinder retaining clips are fitted incorrectly. The smaller curved clip is towards the backplate. Note the
locating pips that hold the clips together.

When bleeding you can use an assistant to pump the pedal solid, and then release the bleed screw - pedal goes to the floor and hold it there, tighten bleed screw before pedal is allowed to rise again.

Jonners

[Richard the old one]

I believe you need to adjust both brake drums before you check on the brake pedal travel / feel as the one you have not adjusted may require an excessive amount of slave cylinder piston travel if you have not set it up.

To ensure that you have got all the air out of the master cylinder the trick I have used is to get an assistant to press on the brake pedal so that it is firm and then to crack each connection on the master cylinder. If there is any air trapped it will be forced out followed by brake fluid. As soon as brake fluid flows tighten up.

[tarynus]

Hi richard,
Sorry but what do you mean by cracking each connection? Do you loosen the 2 pipe unions on the MC?
Also I did adjust both rear brakes but the the problem is the same.

[Richard the old one]

In response to your question. Yes. Loosen each connection in turn just sufficient to allow any air and a small amount of hydraulic fluid to escape before you re tighten the connection.

[tarynus]

Ok I ll give it a try thank you