Technical Swapping Drum brakes to disc on rear wheels

[anyzunstudios]

Hello people!

Today let's start another of my weird stuff...

I HATE DRUM BRAKES! They're ugly, not stylized, makes the car looks cheap and not sport.

So other day taking a look at scrapyard I found a petrol 1.4 95CV Grande Punto Sport/Emotion with rear disc brakes...OMG! I said. Then, I bought the steering wheel (It's more sportive than mine)

But I can't pass that opportunity. In Spain is kinda weird to find out those kind of brakes. So I asked my personal mechanic about how is possible to swap my brakes with those, and he said me that I need to change whole rear axle. Swapping rear axle will cost me about 140€...Well it's ok.

I sent a What'sApp message to the scrapyard guys and they told me that it will cost me 180€+send them to my mechanic... Bullsh**!!!

As we know at Spain, we must to homologate any changes on our cars, even if it is for a better security reason like this. The guys who they work at those "car inspection companies" (IDK who it is called in English) they are sons of a very "happy" women and they used to get you mad until you start to cry in front of them and that makes them to be a better people and then approve that modification. So you must to pay a engineer to make all papers and test to have all you stuff legal. It will cost about 250€+taxes in case that you don't need to make braking tests that it will cost 250€+taxes+350€+taxes due to braking tests...Well...as far as I know you don't need to change rear axle, but you need to to others mods BTW

Well guys, I hope that this project can be finished properly without too much headaches

Greetings!

 

[Bernievarian]

Hola Julio, nice to read from you again !

do you really think those sons of happy woman would detect the car was originally equiped with drums vs disks now ? as far as I know (at least here in Belgium) the MOT Guys will just bring the car to the brake Bench and check if it brakes ok (strength, balance)
Beside that spraying the uggly drums in black does pretty look nice if hidden behind nice (covering) alloys. Mine still has the original 16" and TBH I don't feel them that uggly (the drums), Of course tha'd be a different story if you painted them yellow (or pink) ...

Kind regards, Bernie

 

[chris3234]

Personally I wouldn't bother many cars even today have rear drums simply as small cars don't require rear disks as they do about 20% of the work

Get some new drums and paint them with a few coats of Matt black and they will look fines. Sounds like you be spending half the cost of the car to make the rear brakes looking better

 

[TigerTom]

If the abs sensors are different on the rear discs you might run into issues with the ECU.

Speculation on my part but worth checking into before coughing up.

Drums are fine, they don't look as nice, but most of the weight in these cars is up the front end.

I'd spend the money of a nice set of more closed up alloys personally. Be a much better bang for buck upgrade.

Go for some nice 17's in the same size as the factory optional upgrade and you'll be fine.

 

[Appierre1]

Hi Julio, Agree with Bernie. When renewing all my brakes I painted the new rear drum brakes in a high temperature primer and satin black brake paint on my orange 1.3 GP everyone says they look great if even noticed as they are more difficult to see behind the alloys. Probably better spending all that money on better front brakes, though standard certainly do the job.
Cheers Appierre1

 

[Bernievarian]

Hola Julio & All,

this is how it looks, painted @ last summer tyre change (2017): roughtly de-rusted with wirebrush and direct spray with standard glossy black off a Lidl shelf (cheap) !!

BRs, Bernie

 

[Pugglt Auld Jock]

Ok, I do get what you're saying about the visual impact of the disc brake setup, especially if your wheels are very open with thin, or few, spokes. If you have a nice sporty motor with discs as standard it can lift the look a lot by cleaning up and painting the caliper. However maybe worth considering that discs are very exposed so rear discs tend to corrode quickly - drums, being enclosed don't to the same extent. The calipers themselves are totally exposed so seized pistons and, more often, seized up hand brake mechanisms are common - the wheel cylinder and auto adjuster on a drum set up are inside the drum so protected and a wheel cylinder is a fraction of the price of a caliper if things get really bad. All in all, unless the vehicle is high performance and needs the extra performance a disc brake can give, I'd much rather have the drums and spend my money on something more exciting. Have you considered that your insurance company may consider you to be a greater risk just because you are changing the car? This may cost you.
At the end of the day though, I love changing and modifying "stuff" so I wish you good luck with this and hope you have a good outcome.
Regards
Jock

 

[Bernievarian]

If the abs sensors are different on the rear discs you might run into issues with the ECU.


Drums are fine, they don't look as nice, but most of the weight in these cars is up the front end.

Very good catch Thomas regarding the ABS sensors !
But I must disagree with the second statement: these cars are almost balanced; what we must take into cinsideration is the mass transfer, which while braking strongly enlightens the rear axle, as much as to need a repartitor in the brakes circuit !

BRs, Bernie

If someone here helped You fix -or better, understand- your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)

edit: Added 2nd weight table...

 

[anyzunstudios]

Hello guys

I think that all of what you have commented seems right, and black drum brakes looks cool, they are hard to notice aswell, maybe is what I will do. I have 15" alloy rims, but for the price of swapping drums I'd do things more interesting instead. Thanks for all info and suggests

 

[Pugglt Auld Jock]

Hello guys

I think that all of what you have commented seems right, and black drum brakes looks cool, they are hard to notice aswell, maybe is what I will do. I have 15" alloy rims, but for the price of swapping drums I'd do things more interesting instead. Thanks for all info and suggests

I hope you're happy with your decision and if we've been of help that's just great!

Do get back to us with what you finally do. A few pictures would be nice too

All the best
Jock

 

[AndyRKett]

Just remember, disc brakes especially the rears, don’t always look better, sometimes they can just look silly

 

[derbyshire gp]

As bernie has already said paint the drums.
My 2012's drums were badly corroded so a quick wire brush and a coat of hammered enamel in a dark grey/silver looks far better than rust especially as i have the 17" twin spoke alloys xfromfx