Technical Rear drum brakes shoes and cylinders

[lukish]

Hello, I need urgent help. Fiat Panda 1.2 (2007) version 169AXB1A 01C. MOT failed today due to, among other things, “Service brake effort inadequate at wheel Nearside Rear” and “Parking brake inoperative on one side Nearside”. I asked the garage where I took it for the MOT for a quote to fix it, they said unsure as they would have to strip that rear brake, but that it may come around £600!

So after watching a few videos and reading up as much as I could on this forum, this afternoon I decided to have a quick look inside the brake to see what to do next. I’m attaching a few photos below.

Looks pretty bad to my untrained eye. I’ve decided to change the whole thing: shoes, springs, adjuster, cylinder, and perhaps the drum?

BUT! I’ve spent a long time – I think at least a couple of hours, maybe more! – trying to find the correct parts, and despite a lot of reading I’m more confused than when I started.

First, I do not know whether this car has ABS – some parts are only for ABS models!

Then, with regard to the cylinder, I do not know which one to get. And the ebay checker doesn't seem very reliable...

On the inside of the drum, as you can see from one of the photos, I could read the following:

7750119

MAX DIA 139 181.35 mm (I think)

Finally, I stumbled across koalar’s comment earlier this year: https://www.fiatforum.com/threads/panda-169-abs-fault-speed-sensor.505609/post-4722832 :

“Here in the UK the cheapest way is to buy a complete set

Double check everything, there are 3 types of rear brakes used

And At least two types of rear drums, the diameter and part number should be stamped into them”

So would any of you know please the correct set/kit for my car? It would really help me.

Tomorrow I plan on re-opening the whole thing and checking the handbrake cable – is it worth buying a cable already now, in case it needs replacing? I only have 10 days before the re-test.

And I also plan on buying a hub nut, in case I need to remove the hub, which from what I understand will make the whole process easier.

Thank you all.

 

[koalar]

First the easy part

It's a Bosch system with ABS

Both sides have to match so you will need a pair

Drum look okay, yes cast iron is pourus but should clean with brake cleaner

Be careful choosing a pre assembly some are missing the adjuster but have a metal space in the photo

1 two springs is the Bosch system
2 adjuster, some online just have a spacer instead
3 including cylinder
4 round retainer, the wrong types are square


They start at £22.75 plus postage, probably I bit too cheap. I pay around £50


Can be quite stressful ordering online when you are on a time limit, phone you local motor factors might be an idea

GSF have nothing listed
Euro car parts is £100

 

[The Panda Nut]

Go to shop4parts web site and you should get what info and indeed parts you need. £600 is not even stupid its obscene and outrageous! 150 would be more than enough!

 

[koalar]

I removed the hub and disconnect the handbrake cable, the cable should not need replacing


Here me connecting the handbrake cable and fitting the shoe assembly

It can be done without removing the hub, it's a pain fitting the springs though

 

[koalar]

The wheel cylinder can be a pain to change



You can't get a socket on the bolts that hold the wheel cylinders on, without loosing the backing plate

I believe it's a 6mm hex, socket that's needed but don't quite me

You need a decent brake flare spanner to undo the pipe, most of the time it will be corroded to the pipe and not spin, If you keep going you will just twist the pipe off, instead hold it still and twist the wheel cylinder off

 

[lukish]

Thank you very much everybody for your help.

Two more questions: when you say "Both sides have to match so you will need a pair" does it mean I have to change the other side now, or can it wait for milder weather? I'd rather not do it now. Could it cause problems for the MOT?

Also, just to make sure I got it right, am i correct that the cylinder need not be branded Bosch, it's just that it needs to be for a "Bosch system", but as long as it is, I can buy a compatible brand e.g. Febi or others?

I've seen for example that the Euro Car Part set at £100 is branded Pagid, but in the specs it says for "Bosch system" (https://www.eurocarparts.com/p/pagid-brake-shoe-kit-122580038). So if I were to buy that, the cylinder will presumably be Pagid not Bosch, but still compatible right?

So, final check with you before I order the parts (I hope it's ok to post links to ebay):

1. Cylinder (Bosch): https://www.ebay.co.uk/itm/116049887546 or, if it can also be another brand, then Borg & Beck: https://www.ebay.co.uk/itm/315544661488)

2. Adjuster: https://www.ebay.co.uk/itm/353054973590

3. Shoes and springs (Bremtech): https://www.ebay.co.uk/itm/333150044752

Alternatively, would it be correct to buy this:

Pardon our interruption...

And then just the adjusters separately?

Following koalar's advice I won't buy the drum.

Thank you all again. I'm going out while it doesn't snow to clean the cylinder screws and apply some wd 40 in preparation for when I will receive the parts.

 

[koalar]

"Both sides have to match so you will need a pair" does it mean I have to change the other side now, or can it wait for milder weather? I'd rather not do it now. Could it cause problems for the MOT?"

Should pass an MOT as long as the other side is in reasonable condition

Also, just to make sure I got it right, am i correct that the cylinder need not be branded Bosch, it's just that it needs to be for a "Bosch system", but as long as it is, I can buy a compatible brand e.g. Febi or others?

Yes any make just the Bosch system

I've seen for example that the Euro Car Part set at £100 is branded Pagid, but in the specs it says for "Bosch system" (https://www.eurocarparts.com/p/pagid-brake-shoe-kit-122580038). So if I were to buy that, the cylinder will presumably be Pagid not Bosch, but still compatible right?

I have fitted the pagid pre assembly from ECP, they on a 50% sale at the time

"And then just the adjusters separately?"

I have never found decent adjusters at a reasonable price, the are some substandard ones without the bimetallic strip, I have always either cleaned up the old part and tested or bought as a complete assembly

These are wrong

1 only 2 springs each side instead of 3
2 square retainers instead of round

This is the Lockheed system not bosch

 

[lukish]

Thank you very much again, you've saved me from potentially buying the wrong stuff. I've bought nos. 1 and 3 from my earlier post, i.e. the cylinder and the shoes + fitting kit. I'm not buying the adjuster for the moment: I plan on cleaning them, and then if they look ok I will simply put them back in. Or how should I test them?

In the video by bodgit and leggit garage, at 09:56 just before removing the bleed nipple, he jams a pipe against the brake pedal see . Anybody tried that before? I presume you won't get too much brake fluid out, but I will put a pan down anyway.

I managed to remove the rust and gunk from the three cylinder bolts on the back of the plate, and after that I've sprayed them with WD 40. They don't look too bad now. Hopefully they will come off!

 

[koalar]

Koalar random thoughts | FIAT Panda (Mk3)

You can tell if the coil pack is getting a control signal and giving a good spark like this If one is weeker and the spark does not jump as far than the others it's suspect It is possible to get a jolt if you do something wrong, probably not a good idea if you have a pace maker As long as the...

www.fiatforum.com

Testing the bimetallic strip and adjuster in the link above, they are Lockheed but the principle is the same

Soak in brake /carb cleaner and brush with an old toothbrush, as long as the racket isn't worn or the bimetallic strip fallen off they are usually fine

I take the top of the reservoir cap off and cover the top with cling film, undo the pipe and bung the end, I just loose a few drops normally, there's no right or wrong ways, just what works for you, it's the way I have always done it

It will but unlikely the pipe will undo as in the video, at this age it will much safer to hold the pipe still and twist the wheel cylinder instead

From memory you don't have to fully remove the backing plate bolts, just loosen them and tilt the plate to get a socket in, I might be wrong here as a have a special spanner so don't need to undo the backing plate

The end of the video isn't necessary, they are self adjusting, wind them fully in assemble everything, then pump the brake pedal and pull the handbrake until the adjusters stop ratcheting out

Be careful when fitting the adjuster, there's four different orientation that it fits,

Looks like fairly new shoes in your photos, have you had the car long, I suspect they started weeping after being disturbed when the shoes were last changed

 

[lukish]

It will but unlikely the pipe will undo as in the video, at this age it will much safer to hold the pipe still and twist the wheel cylinder instead

Thanks again, will do.

wind them fully in assemble everything, then pump the brake pedal and pull the handbrake until the adjusters stop ratcheting out

Thanks, I will follow the description you have here: https://www.fiatforum.com/threads/rear-brake-adjustment-adjustment.483255/post-4558943

When do I know when I have pressed on the brake pedal enough times? The clicking sound of the ratcheting mechanism of the adjuster will stop?

 

[koalar]

Thanks again, will do.

Thanks, I will follow the description you have here: https://www.fiatforum.com/threads/rear-brake-adjustment-adjustment.483255/post-4558943

When do I know when I have pressed on the brake pedal enough times? The clicking sound of the ratcheting mechanism of the adjuster will stop?

Yes

Or follow the instructions here

 

[lukish]

That's brilliant! Thank you VERY much again. You guys are saving lives (and the sanity of many people)!

I got the little Panda a bit more than 3 years ago if memory serves. Since then I've changed the exhaust, front shocks, front brake discs and pads.

I didn't use it for almost two months this summer, and I had left it with the handbrake on: only this morning I read elsewhere on the forum you're not supposed to do that if leaving the car for long periods of time. I think at least one of the rear brakes must have been a bit seized when I first tried to drive it. You live and learn.

Anyway, yesterday I bought the replacement parts, but I'm now thinking I might as well also buy new bolts securing the cylinder, but could not find on FIAT eper. Does anybody know what kind of bolts are they?

PS a few pics of the cylinder bolts and brake line after I cleaned them a bit. I've been spraying them with WD40 a few times over the past two days, and will continue doing so until I do the job, hopefully during the weekend. Will use the lighter on the brake line to try and soften the plastic coating as some have suggested

 

[DaveMcT]

Put a layer of sandwich poly bag under the brake reservoir lid. It reduces fluid flow when the pipe is opened.
Loosen any hard pipe brackets at the back of the brake plate. Loosen the back plate from the axle.
Hold the flare nut with a tight fitting flare nut spanner. I have an imperial size that fits perfectly.
Remove the bleed nipple and TURN THE WHEEL CYLINDER. This avoids the steel brake pipe getting twisted.
When it's apart, use a gas lighter to heat the flare nut. Don't go mad - just enough to soften the plastic coating on the pipe. The nut will spin free and you will see white powder underneath. This is oxidised zinc plating on the steel pipe.
Don.t forget to remove the plastic from under the brake reservoir lid.
AFTER the MOT, grease the pipe and nut with red rubber grease. If you do the test with looking oily they'll fail it on a fluid leak. Clean it off next year. My cars have been like this for years no problems. But leave then dry and the steel will rapidly rust into holes.

If the rubber hoses between axle and underfloor steel pipes are looking elderly, get braided hoses from there all the way to the wheel cylinders. Braided rear pipes will not affect the brake feel. It's done once and will never darken your doors again. The rubber hose is removed as above. Cut the hose and spin the fragment off the pipe end. Heat the nut to free it off, etc, etc.

 

[Yolanda]

Youv'e done a great job of cleaning everything up. Forget WD use a good quality penetrating oil, or make your own using Acetone and a light oil in a 50/50 mix. Also when you put everything back together put a smear of copper grease on all the threaded parts for ease of removal next time.

 

[lukish]

Thank you Dave and Yolanda.

I've started the job this morning at 10, all was going well and then disaster: I found the adjuster absolutely knackered. It must have been in that condition for a long time. The adjuster wheel is completely stuck, the body of the adjuster destroyed, and even the bolt broke off at one end! See pics. No idea how that might have happened. Couldn't find the missing bits inside the drum, so who knows how long it's been like that.

Problem is I don't think any local car parts shops have the adjuster, and while I've found it on ebay it would take too long for it to arrive before the MOT re-test.

Is it possible to re-use it temporarily, to pass the MOT retest, while I wait for the part to arrive? If so how would I go about doing that?

 

[koalar]

Someone has fitted it incorrectly in the past, it's not been properly located in the slots on the edge of the shoes, allowing it to drop down and hit the hub

Can you get it through an MOT

Yes, as per earlier video, you will have to manually adjust the side withe the adjuster not working it's the same as the other side, a right faf, and time consuming, also if there is a lip on the edge of the drum it risks damaging the shoes

It's not a rare part used on multi vehicles such as the ford KA mark 2 up to May 2015

Phone round some local motor factors, assuming your not in the middle of the sticks, if they have no stock most will be able to get them next day

Amazon prime in next day if that's any use

 

[lukish]

Thanks again koalar. I called three fairly local motor parts shop, the closest doesn't have it, the two half an hour away have it, one for £66 one for £75 each. Amazon doesn't appear to have it. On eBay it's about £25 but delivery takes a week.

I have managed to unblock the screw, but could not avoid damaging some of its teeth as I had to use a plier wrench. I've cleaned it and oiled it and now it turns fairly well...

Moreover, I have noticed the adjuster also lacks its own little spring: I'm pretty sure I haven't lost it, it was never there to begin with! Which is probably why the adjuster dropped down and hit the hub and got eaten up. The spring I'm referring to is no. 7 in this diagram: it doesn't come with the fitting kits, but only with buying a new adjuster.

Such a pity though. After discovering that the adjuster was gone I still managed to have a go at breaking the two cylinder bolts from the rust, they actually started turning pretty easily. Cleaning off the rust and soaking them a dozen of times over a few days first with WD40 then with Plus Gas must have worked.

The only thing I have not yet tried to undo is the flare nut and brake pipe. It will be the very last step. As many have suggested, I will try and undo it after I've removed the two cylinder bolts, by rotating the cylinder itself.

Unfortunately I had to reassemble everything in a rush, still using the old bits as I needed the car for the school run... But tomorrow I plan on replacing all parts with new ones, apart from the adjuster, as I'll keep the old one temporarily while I wait for the one from eBay.

Yes, as per earlier video, you will have to manually adjust the side withe the adjuster not working it's the same as the other side, a right faf, and time consuming, also if there is a lip on the edge of the drum it risks damaging the shoes

I assume you're referring to the bodgit video at around 30:35 in, exact moment here , is that correct?

So basically, I will need to adjust the adjuster wheel manually anti-clockwise until I can just about fit the drum back in?

Thanks again for any advice.

 

[koalar]

Yes

Not ideal but will give you some time until the new parts arrive

Basically a pain in the bum and you will have to do the job twice

The small spring is held on the ratchet wheel permanently, it's pretty much impossible to loose

They are a right mess and bodge, be much better once they are fixed properly

 

[lukish]

Right. Managed to replace everything but the adjuster, which should be arriving on Friday. Luckily the flare nut and the brake pipe weren't welded together, and they came apart pretty easily. What I did was break off their bond while the two cylinder nuts were still in place, and then once broken, removed the cylinder nuts and gently turned the cylinder while holding the flare nut still. I never separated the flare nut from the pipe; I just put everything back into the new cylinder, I hope that's ok.

Everything is set up as it should (forgot to take photo of it once mounted; I only have a photo of the new shoes, with the old broken adjuster missing its spring).

However, didn't manage to adjust the shoes as the adjuster wheel isn't moving, and I didn't have time to check why as I needed the car again. The drum went back very easily and spun freely so I think tomorrow I need to re-open and regulate the adjuster if I can.

If I cannot, any advice as to what to do before taking it for the MOT? [Edit: I will try and do what described here: https://www.fiatforum.com/threads/drum-self-adjuster-bad.480484/post-4534025]

The car feels ok when braking, I think better than before (the old cylinder was completely shot), but I can't tell whether that specific brake is working well though...

The handbrake feels much better now, but am I right I regulate it again if/when I have to re-adjust the shoes tomorrow?

Tonight I've also received the vacuum pump so tomorrow I'm going to bleed all brakes.

 

[koalar]

Should start to grip at one click of the handbrake

And fully locked by 3 clicks

Give or take

Both sides need to be the same