A quick Brake Question

[Rich Tea]

Just a quick question, hopefully someone will know the answer....

On the threaded end of the drum brake adjuster, the long fork goes on the back of the brake pad, but which way round does the other end of the adjuster (the socketed end) go? The forks are the same length but one of the forks is thick, the other end is thinner and has a chamfer on the corner.

Should the chamfered side face the drum or the back plate?

Unfortunately it sits under the ratchet lever so its not obvious when you're looking at photos.

Van currently on axle stands, so help appreciated.

Cheers

Rich

[dave friday]

Chamfered side facing the drum,i think it's to allow the pawl to return if it does'nt move the adjusting gear.

[Red Westie]

It is probably worth mentioning that the top return springs are also handed, get them the wrong way around and they interfere with the adjuster wheel.

Martin

[Rich Tea]

Cheers guys

Had a bit of unplanned work this weekend as one of the ratchet levers things snapped and the brake started making bad noises. So had to change the shoes. On top of that one of the slave cylinders was leaking and someone had rounded off the hyd coupling nut. So I had to fit a new cylinder and get a pipe made up.

Sounds like I got the adjuster the right way round then, I though I had put it back the same way that it came off, but couldn't quite convince myself.

With respect to the springs, I assume you mean that if you have them the wrong way round that the long wire from the spring hits the adjuster. The right way being with the short side of the hook facing upwards. Is that what you mean?

Took the van for a run in earlier, the drums hit 86 degrees C. Do you think thats about right, or do you think they need backing off a bit (I'm thinking that sounds hot)? Also pedal doesn't feel quite right so, off to do some more bleeding.

Cheers

Rich

[Red Westie]

Cheers guys
With respect to the springs, I assume you mean that if you have them the wrong way round that the long wire from the spring hits the adjuster. The right way being with the short side of the hook facing upwards. Is that what you mean?
Rich

Yes the long wire hitting the adjuster because the spring is upside down (not the wrong way around)

New shoes on old drums take some bedding in and will take a while before they are working as well (power wise) as the old setup.

Rear brakes can get very hot...as long as they are not binding and free rotate there is no reason to give them more clearance.

Martin

[Rich Tea]

Thanks Martin,

Still can't get the pedal feeling right, bled all the brakes except the front right as the bleed nipple had no corners on it (thats a job for another day ).

The brake pedal is soft to start with, then the brake bites but it feels like the pedal is maxing out on travel. The van seems to stop ok, allthough the front end dives rather more than I remember (perhaps thats to with your comment on bedding in).

I had a look at the drums again, it seems like theres a gap between the brake pistons and the shoes, like they've retracted further than they should (on the side with the new cylinder, but not on the other side). Is this supposed to happen? Is there a return spring in the slave cylinder (febi)?

Cheers for your help

Rich

[DevonAid]

There was a recent post regarding brake cylinders and internal springs, worth a quick search.

Just replaced rear shoes yesterday, had a bit of bother getting a decent 'pedal'. Persevered with carefully manually adjusting rear shoes with drum in position, occasionally pressing brake pedal to centre the shoes, continued adjusting through the backplate hole until they just started to 'catch'.

Even though the cylinders were ok, finishsed off with a quick bleed of the brakes - using an assistant (cheers the wife!) in the driving seat as the self bleed kits never seem to do quite as a decent job as manually pumping fluid through. Brakes now restored to full operating conditions with a good 'pedal'.

Good luck

[Red Westie]

How much brake fluid did you loose when changing the slave cylinder and metal brake pipe? did you allow the resevoir to empty? if so you will need to bleed the entire system as it sounds like there is still air in the system.
Rear brake adjustment should be done with a slackened hand brake cable.

Martin

[Rich Tea]

Hi Martin

Not much fluid loss at all, I was really careful. I filled the reservoir to max before I started, put cling film under the reservoir cap, and plugged the end of the flexi quickly after unscrewing the pipe. Probably lost less than an egg cup full. The reservoir never got near to minimum even when bleeding. The only thing that wasn't ideal was that I didn't bleed straight away (had to wait for my wife to come home). However, after unplugging the flexi and attaching the new pipe it wasn't long before fluid started dripping out of the bleed nipple of it's own accord anyway, which I quickly tightened up.

I was thinking trapped air, but after bleeding twice none came out. After getting my wife to pump through half a litre of DOT 4, she was getting a bit fed up.

Hand brake was off for bleeding, but I didn't slacken the cable elsewhere. Hand brake is ok on notch 4 but is solid on notch 5 at the moment.

The bit I'm not getting is why do I have gaps between the pistons and the shoes? It goes without saying that I must be lossing effort by closing this gap up each time I brake. I've been trying to find the thread DevonAid mentioned, but no luck yet.

Cheers

Rich

[DevonAid]

I've had a look but can't find the thread either: I'm sure there was a similar thread in the last 6 weeks with a question raised regarding brake cylinders having an internal spring.

There was a recent post on the quality of brake parts which gives some background, but not quite what I was thinking of:
https://club8090.co.uk/forum/viewtopic.p ... r#p7595134" onclick="window.open(this.href);return false;

[Rich Tea]

Cheers Devonaid, still looking as well, but can't find the thread either.

I Just examined the leaking slave cylinder which I removed and swopped for a new one. It does have a spring inside it, the replacement cylinder I fitted doesn't. Assuming that the off side cylinder was the same, it appears that I'm now running with one slave cylinder with a spring and one without.

I bought a pair of cylinders at Christmas which I didn't get around to fitting, until at the weekend when I was forced to takle the nearside drum, so this is anomaly can soon be rectified by fitting the other springless cylinder.

Could this anomaly be the reason why the pistons pull back from the shoes (on the side with the new spring less cylinder)?

Any help appreciated.

Rich

[Red Westie]

Yes indeed....the wheel cylinders have a weak coil spring inside them to keep them extended and in touch with the shoe heel contacts. As you pointed out previuosly, you don't want the pistons to retract back to their resting position otherwise this will cause excessive pedal movement moving enough fluid to push on the shoes.

Martin

[Rich Tea]

I can definitely see the benefit of a spring, but the new ones I bought have no springs, I got febi bilstein ones as I thought they would be a reliable brand.

I want to ask if having the spring is essential, but I guess my experience is suggesting there could be problems if you don't have it.

I guess the right question is, will the cylinder "bed in" and stop doing this, or will things improve if I have a pair of cylinders without springs? Or (I can hardly bring myself to say this) do I need to replace brand new cylinders for different cylinders (and if so so which brands have a spring)?

Cheers

Rich