One for all those with dirty finger nails.

[Pugglt Auld Jock]

This is one for all you guys, like me, who like nothing more than getting your hands really dirty. I'm sure we've all had problems with general and electrolytic corrosion so this is one to enjoy. I particularly like that hydraulic splitter he uses on the caliper.

https://www.youtube.com/watch?v=YYXlT3VGihY

I'm really not convinced as to the need for discs on rear brakes. They are understressed when compared to fronts so I don't think the performance factor comes into it. The discs rust out quickly due to exposure to all the crap the front wheels are throwing at them. Self adjusting mechanisms and hand brake actuation is complicated and difficult to mend, also tends to seize up more than drums. Finally, when they do become unserviceable they are much more costly to buy parts for.

Maybe I should start a campaign for the appreciation of drum brakes on rear axles? But, oh silly me, then the inspection service interval would involve removing rear wheels and drums instead of just glancing at the pads through the alloy spokes.

 

[AndyRKett]

I remember working on a couple of C5s in the past but on electrical problems, they did have a multitude of problems, the dealership I used to work at sold one and this one car accounted for about 60% of customer problems as it literally came back every week with something wrong.

However I’m all for disc brakes, I hate drums, with one exception, my old SAAB 900 used to have both drums and discs on the back, the drums where for the hand brake and where on the inside of the hub of the disc and the disc brake on the outside where for the foot brake. This meant a good simple hand brake and non fading uncomplicated rear discs. The actual disc was no different really but if you needed to replace parts on the hand brake and the foot brake it required quite a lot of bits and Saab bits could be costly.

 

[StevenRB45]

Depends who built the disc brakes and the weight of the car.

C3 weighs less than 1100 kg, Relatively big vented discs on the front. As a result the rear brake effort is nothing in most circumstances. Couple that with no backing plates on the brakes to save a few quid and at 3 years old it's likely it'll need new discs on the rear to get through the 1st mot due to corrosion.

However Mazda has 5mm of rear pad left and discs are fine..it's had the same discs and pads for 9 years and 82k so far, there's a reasonable chance it'll have the same ones for it's entire life.

Probably a difference in 1st of all parts quality but mostly weight/brake distribution meaning the rears get used enough not to pit.

 

[chris3234]

Rear discs are certainly of use on larger Cars especially those that get used for towing
Smaller study not as much



Still shocked at the condition of those brake's callipers ?

 

[portland_bill]

I was surprised to see that the Fabia had rear discs. In firm braking I can actually feel them working to help bring the speed down. Stopping is quite impressive. I agree with Jock, rarely actually needed on smaller cars, but Skoda(VW) seem to have got their sums right on this one.

Nice not to have to fight springs on brake shoes. Always hated that job.

 

[portland_bill]

I've seen a few Bodgit videos, most seem quite informative, and 'real world' situations and solutions, but this one had me cringing a lot.

Citroen have always had an odd approach to some of their engineering solutions, avoiding any conventional method to apparently just do it differently, without any apparent improvement. Using the caliper through bolts to mount it seems a solution guaranteed to bring problems. Saved the cost of two cast lugs and two extra mounting bolts.

My brother is currently running a Peugeot 307 2.0 petrol. Taking the cylinder head off that was a nightmare. Perhaps with the engine out of the car it would just have been 'difficult'. Cambelt fit and tension also incredibly awkward. If tension not right after the normal two complete turns and recheck, bottom pulley has to come off again to allow the covers to come off to gain access to the tensioner. Designed by someone who probablyhad never carried out, or even understood the operation.

 

[DaveMcT]

Try doing the cam belt and/or cylinder had on a Fiat Punto Mk2 HGT. I loved the car but...

The cam belt cover is so close to the inner wing the only tool to fit the retaining screws (torx of course) is an 8mm screwdriver bit turned with 8mm ratchet spanner. "normal" short 10mm hex/Torx bits were too long.

Fitting the aux belt needed the jack to lift a spanner on the tensioner. There was no space for a long spanner.

The cylinder head had to be removed complete with inlet manifold.

 

[DaveMcT]

Drums don't pulse very well so ABS systems reduce drum brake pressure rather than pulsing.

I had a Citroen BX 1.9GT which was actually a very good car. Being a Mk1 it had satellite style switches on the instrument binnacle with no stalk controls. Mine had rusty rear discs which had to be replaced but it had done just 10,500 over 2 years so no surprise the brakes were hardly used. Brake dIsc corrosion was never an issue when I had the car. They were retained by the wheel bolts so easy to change.

The VERY powerful brakes used Citroen's LHM mineral oil hydraulic system. Probably due to the high pressure hydraulics, the calipers were small but they wroked very well and must lower the un-sprung axle weight. The brakes worked only if the engine was running and (accululator exhausted), so the hand brake worked on the front discs. It could easily pull the car up if needed but hand brake turns were no fun. The downside was you could not drag the handbrake to clean the rear discs.

The Punto Mk2 HGT and the Panda 100HP both have the same rear discs with rotors the same as the basic Pandas use on the fronts. Both of my cars developed a wear lip on the rears so they do get used. In corrosion terms, all discs all look the same. As for disc corrosion, stainless discs would solve the problem - for a price.

 

[portland_bill]

As for disc corrosion, stainless discs would solve the problem - for a price.

Motorcycles use stainless discs, and I think that contributes to the lag and poorer performance when wet. Being exposed is the usual argument, but some early Guzzis had iron discs and didn't suffer the frightening lag. Did suffer the frightening corrosion though and looked horrid, so stainless were used soon after.

 

[Pugglt Auld Jock]

I was surprised to see that the Fabia had rear discs.

The MK1 Fabia 1.9tdi my boy owned had rear discs. I had an awful time with the handbrake not releasing fully, even new cables didn't sort it. Then someone told me the extra, externally mounted, return springs on the Alhambra/Galaxy/Sharan could be made to fit. Never had a problem after that.

 

[rmjbn1]

That's a fair point, Jock.

Just the other day as I was struggling to prize my rusty drums off and contemplating the difficulty of changing shoes and cylinders, I was thinking 'why don't they just fit discs?!'

After all can drums really be cheaper to manufacture, and especially install, when they're as fiddly as this?

But, yes, I've had four seized rear calipers on two Mazdas in recent years because the handbrake mechanism had seized and caused the inside pads to wear down and finally lock up.

And I agree, a small light car soesn't really need them.

But I did like the all round discs on our Citroen CX Safari. In combination with the anti-dive/anti-squat hydropneumatics, it really felt like the car was being pulled back from behind .

 

[DaveMcT]

Motorcycles use stainless discs, and I think that contributes to the lag and poorer performance when wet. Being exposed is the usual argument, but some early Guzzis had iron discs and didn't suffer the frightening lag. Did suffer the frightening corrosion though and looked horrid, so stainless were used soon after.

1970s bikes had horrible brake lag with wet discs and they were not significantly better performing than the drums they'd just replaced. My last bike was a 2008 BMW 1200 boxer twin. That had all round discs and it pulled up hard no matter the weather. My biggest complaint was the rear disc was under sized for the job demanded of it. It worked fine but the wear rate was really bad and at £100 for one little disc plus pads it wasn't cheap

The previous bike was a 1997 Yamaha 900. the brakes were ok (wet or dry) but a bit wooden feeling. I fitted R6 sports "blue spot" brake calipers and master cylinder and it stopped on a sixpemce. No ABS but so controllable. Wet weather was never a problem.

The 1970s Guzzis (and Ducatis) stopped well, because their Brembos were just so damn good.

The Japanese had a habit of fitting a brake master piston that's just too big. I have a 1976 GT750 triple with twin discs. They are OK but nothing special. the GT550 had just one disc but used the exact same master cylinder. No surprises the stopping was best described as adequate. The mid 1990's Yamaha Diversion 600 with single disc was nothing special. But withn a smaller master (1/2" v 5/8") it stopped very well indeed.