Technical Intermittent rubbing sound from brakes

[The Panda Nut]

OK, local garage is booked out for a month, so I guess I'm doing it myself.

So what I need is:

• 32mm socket for hub nut
• 10mm flare spanner
• Brake fluid - do I need a bleed kit?
• Replacement wheel cylinder
• Replacement adjuster (already ordered)
• Shoe fitting kit (to replace missing retaining pin)
• Probably lots of penetrating fluid

I have 3/4" and 1/2" socket sets (also with hex bits), 1/2" and 3/4" torque wrenches, 1/2" breaker bar and whatever else I've used to remove the drum and shoes so far.

I see in some videos they are removing the backing plate to get the cylinder off - is this recommended?

And should I be doing both cylinders at the same time? I haven't looked at the other rear brake yet, though it seems to work fine and isn't making any noise.

A kit with shoes clips et al. and cylinders is the cheapest way I find

 

[koalar]

I still don't understand why you'd want to take the hub off; I've replaced the rear drum brakes on a 169 and never felt the slightest need to do this

I don't think they have a choice

I am 70% certain you can't tip the backing plate enough to undo the wheel cylinder

You can do it both ways if you are just changing the shoes

I just prefer, for sake of one nut, and it's not that tight the easy, of cleaning everything up, adding the grease to the contact point first

Look at the video I posted earlier, under 40 seconds to attach handbrake cable fit the shoes, adjuster and springs and that's with a fumble and trying to stay out of the way of the camera, but not including the retaining clips, easier to align the adjuster properly in the slot of the shoes

. Once the drums are off, you have access to everything you need. And you can easily get the drums off by screwing suitable bolts into the holes for the locating pins; they're threaded for this exact purpose.

It's not necessary; if you have a second person to pump the brake pedal, you can do it the old fashioned way.

But it does make the job easier, and means you don't have to find an assistant for a few minutes.

My preference is to use a vacuum bleeder, as it minimises the risk of accidents and keeps the mess to a minimum. You can also use a pressure bleeder, but if you are not careful, this can result in brake fluid spraying into all sorts of unwanted places.

I prefer to activate the abs module, Unfortunately the bleed function is missing from multiECUscan so isn't an option for most people

A pipe and an assistant is just as good anyway

 

[Quantum Fireball]

Thanks for the input, everyone. I've ordered a full Febi shoe kit with cylinders. I suppose it'll be good to have all the parts in case something else turns out to be broken (or I break it!).

I'll get the socket for the hub nut just in case the backing plate does need loosening or removing to get the cylinder off properly.

 

[Yolanda]

Do one side at a time, then if you forget where something goes you can reference the other side.

Good luck.
PS If you lived near me I would gladly help you with the job.

 

[DaveMcT]

My docket set has one that fits the hub nut so I remove the hub. It’s definitely easier.

Brake springs can be tough to fit. Get a professional hook tool.

Make sure you are supplied the right parts. 500 brakes and Panda brakes look the same but they are different.

Good advice on how to remove the slave cylinder. DO NOT turn the flare nut. It will twist the metal pipe. Turn the cylinder instead.

You will need to remove the interior centre cover (4 x M6 nuts) to loosen the hand brake cable adjustment. A parts picking magnet is a must-have. Use sticky grease on socket for refitting the nuts.

The brake shoe adjustment is best set so you can just get the drum in place. Then slacken the adjuster two clicks. You can access it via a wheel bolt hole. Last of all set the handbrake lever height.

 

[koalar]

My docket set has one that fits the hub nut so I remove the hub. It’s definitely easier.

Brake springs can be tough to fit. Get a professional hook tool.

If you take the hub off, no hook tool is needed, as the whole assembly including all the springs can easily be fitted with nothing more than a screwdriver

Here me fitting the handbrake cable, shoes and all springs in one go

Make sure you are supplied the right parts. 500 brakes and Panda brakes look the same but they are different.

There's 3 types of rear brake drums fitted to the Panda

Bosch none ABS
Bosch ABS
Lockheed

The brake shoe adjustment is best set so you can just get the drum in place. Then slacken the adjuster two clicks. You can access it via a wheel bolt hole.

No idea what all this is about

The brake are self adjusting

Just throw it all together with the adjuster fully wound in, and then keep pumping the pedal until the adjuster stops clicking


No idea why you need to pre set it unless the adjusters aren't working properly, in which case just fix it properly

 

[Quantum Fireball]

Finally made some progress with this today. I replaced the wheel cylinder, adjuster, and the shoe retaining pins.

Turns out the nut on the brake pipe nut was 11mm and the flare nut spanner I got was 8/10mm - no one seemed to have the right size on a Saturday, so I just used a normal spanner (and the recommended method of rotating the cylinder) and didn't seem to break anything. I couldn't get one of the backing plate bolts out (head rounded), but loosening one side seemed to be enough to just about get a spanner in behind to remove the cylinder (painful to do though!).

I also didn't have a replacement hub nut and just used a breaker bar to re-tighten the old one (as my biggest torque wrench only goes up to 210 Nm), hopefully not a terrible mistake?

Once I started driving, the ABS warning light came on, but after a longer drive and a few restarts it seemed to disappear. Maybe just some dirt on the wheel sensor? I didn't know which part that was at the time (I do now...). I wasn't able to check the ABS error codes (I don't think I have the right cables for Multiecuscan to talk to the ABS controller).

The brake seems to work fine, except now there's a serious imbalance with the handbrake - if I tighten the cable enough for this side to work as expected, the other side is pretty much fully locked after one click. Maybe the adjuster is broken on that side as well?

 

[Yolanda]

Adjust them manually. To do this slacken hand brake cables right off. Remove drums. Using a flat screwdriver turn the adjuster bar nut to expand the shoes until you can slip the drum on with a slight bit of interference this will be the lip on the drum providing your using your old drums. Even if you were to be fitting new drums you still want a very slight bit to give you a feel. When the drum is on make Shure, it rotates freely again a slight rub is not a problem. Then tighten the hand brake cables till you have about 4 clicks when the drums won't rotate. Release the hand brake and make sure the drums rotate freely.
I've done this procedure on my car's with rear drum brakes many times as I've found the auto adjusters never quite live up to their name.
If your adjusters are working as they should this afore mentioned procedure won't be detrimental to the way they work.

PS. Turning the adjuster bar nut will if I'm not mistaken might be clock wise on one side and anti on the other.

 

[Quantum Fireball]

Yeah, the adjuster was also broken on the other side (pawl disappeared), so I replaced that and the wheel cylinder (only half working/starting to leak). Now the handbrake is much better balanced between the two sides after adjusting the cable.

ABS light is still coming on intermittently though

 

[DaveMcT]

Mine failed MOT on weak handbrake. I bought new shoes but was given the wrong parts. The adjusters have no visible signs of wear or corrosion but were clearly not adjusting themselves. I wound the adjusters back a few clicks, refitted the old shoes and set the adjusters so the drums were a close fit. The adjuster knurling is accessible through a wheel bolt hole. I used this to set brakes for no binding.
Set handbrake cables for a reasonable lever pull and refitted the centre “console”.
It passed MOT no problem.

 

[Quantum Fireball]

What I found with the adjusters was that the pawls had disappeared (no. 9 in the diagram here - maybe fell off and disintegrated over time?), so they would not adjust themselves at all. I noticed one of the adjusters was stamped Bosch so maybe they were the originals. Handbrake works great now after replacing them.

My current problem is I think I damaged one of the ABS sensors trying (and failing) to remove one of the backing plate bolts on the rear left. I confirmed which sensor is causing errors using Multiecuscan, and it has visible damage.

I've ordered a replacement, but removing it is going to be fun as the bolt is quite rusty and is another crappy Allen head...

 

[AnthonyH]

As a DIY mechanic this was my first difficult job. I'd say it was a nightmare, it took me 6 weeks or so. I broke 3 cylinders, 3 adjusters, and had all of the problems you've had, minus the ABS issue. The guys on here were great and I finally got it done.

Keep going, you will get there!

The brake adjusters and cylinders are a lot more delicate than I imagined.