[PatchyBoy]

In July, five of us embarked on a pilgrimage to Sabarimala, a temple in Kerala - 680 kms drive from Bangalore. I had got the wheels balanced and aligned only the week before and while I did notice that the rear brake pads were rather thin, I felt that they can last another 2000 kms at least. Wrong judgement. 100 kms into the journey, we noticed a grinding noise from the rear right wheel. I checked it and strangely decided it is due to low air pressure, pulled out the air-pump and pumped up the pressure and continued on the journey. 400 kms into the journey, the noise was getting louder and started appearing when ever I touched the brake. By the time I realized that it was due to a worn out brake pad, we were already deep in the forest area and the nearest reliable service centre was more than 200 kms away. So, I decided to continue on the journey. Once we reached the temple and came back to the car, it was decision time.

• Drive down to Kottayam ~200 kms and get the brakes fixed at a not so reliable service centre
• Drive down to Salem ~ 450 kms and get the brakes fixed at a reliable service centre
• Drive down to Bangalore and get it fixed there

Since I did not feel any deterioration in the braking performance and since a friend travelling with me wanted to take the afternoon train to travel to his place, I decided to drive down straight back to Bangalore, ignoring the grinding noise from the rear wheel. Big mistake. Also an unbelievably stupid risk, in retrospect. These are the brakes, for God's sake. Though we made it back to Bangalore without any issues, by the time I got home, I was left with this -

There was nothing left of the rear right outside pad

and metal-to-metal grinding for hundreds of kilometres had also scratched the rotor badly.

Costly mistake. So, I decided to replace both rear rotors and pads. Why replace the rear left rotor, which was still in a good shape, you may wonder. It is always a good practice to replace brake components of the same axle at a time and it is not recommended to replace just one side.

A trip down to the nearest FASS and got these. I was poorer by ₹ 10,292.

Note - Although this post talks about the Linea T-Jet and also uses pics of that specific car, the procedure is usually the same for most cars.

Now that I have the replacement parts, let me get started with the actual process, without any more rants. Here is what you will need :

Parts

• Rear rotors for Linea T-Jet 2 numbers
• Rear brake pads - 4 numbers
• Dot 4 Brake Fluid - 500 ml can

Tools

• 13 mm wrench
• 17 mm wrench
• 10 mm wrench
• 7 mm wrench
• Small piece of plastic tubing 8 mm dia
• Old transparent plastic bottle
• Jack Stands
• Torque Wrench

Process

Park the car on a level surface, put choking blocks under the front wheels, engage first gear, disengage hand brakes. Now loosen the wheel bolts, just a quarter turn, jack the car up and support with jack-stands. The supplied jack alone is never enough to work on the car. Please don't do it. Once supported by jack stands, remove the wheels on both sides completely

There are two parts that we need to remove - the callipers and the pad holders. First, locate the bleed valve, usually covered with a small rubber cap, loosen it a bit and then snug it back. This will help later, as you will see. The callipers are held by two 13mm bolts. Loosen both of them first and then undo completely. Now you should be able to take the callipers out and move them out of the way

Once this is done, the old brake pads can be slid out. The pad holder itself is held by two 17 mm bolts. loosen them and unscrew completely. Now you should be able to take the whole unit out of the car.

Notice the pad on one side is worn much more than the other. That indicates either a stuck calliper pin or a bad piston.

The rotor itself is held in place by two locating pins. Undo them and the rotor should just come out. If there is a lot of rust, the rotor might be stuck and will require a few taps with a hammer to loosen it, but in my case, it just popped right out

Now replace with the new rotor - clean first with a grease removal agent - and put the locating pins back. The new pads come with new clips to hold the pads in place and new bolts for the callipers. Do not reuse the old 13 mm bolts we removed. The clips are snap on.

There are two calliper pins. Remove them, clean and lubricate with brake grease and refit. Make sure they slide in and out easily. Use only brake grease. Ordinary grease is not designed to work at the high temperatures that brake components are likely to see. Now fit the pad holder in place, reuse the old 17 mm bolts and tighten them. Make sure the new pads are sitting in place properly. Make sure that you tighten these bolts with a torque wrench to the manufacturer specified torque values.

Now there is something that we need to do, before we can fit the callipers back. The callipers are equipped with a self adjusting piston, which will be protruding out, as the old pads were far thinner. So we need to push the piston back in. We are working on the rear axle, which also has the parking brakes. In some cars, there is an independent drum brake mechanism, inside the discs and in some cars, like the Linea T-Jet, the parking brakes use a ratchet mechanism to push the piston out and keep the brakes engaged. So, these pistons cannot be just pushed in, but will have to be rotated while being pushed in. While there is a special tool for this, it can be done quite easily with a pair of nose pliers, as long as we have drained the brake fluid and released back pressure first.

When we are pushing the piston in, we are trying to push the brake fluid back into the master cylinder and will be faced with a lot of resistance. So, we will need to crack open the bleed valve, attach the plastic pipe to the nozzle and drain the fluid into a bottle. If we already cracked the valve open and snugged it back up, it will be far easier now, as we have the calliper hanging there, unsupported.

That is the piston screwed back in, all the way. Compare that with the fifth picture in this thread to see how much the piston was jutting out before. The nipple you see in the bottom right is the bleed valve. Never pump the brake pedal, with the callipers detached. The pistons will pop out and can be a pain to put back again. Once you have the pistons retracted all the way, fit the calliper back, using the new bolts that came in the pack.

Once you have fitted both sides, replace brake fluid and bleed the lines to remove any trapped air bubbles. Fit the tyres back and take a drive around the block to ensure that brakes are working fine. Find an empty stretch and try a couple of panic braking manoeuvres, just to ensure that you have optimal braking performance.

That is it, you can drive safely for the next 25,000 to 30,000 kms (strangely, that is how long the rear brake pads last in this car, while the front lasted over 50000 kms), knowing that you can stop safely, when you need to.

Thanks for reading.

[GTO]

Thread moved from the Assembly Line to Technical Stuff. Thanks for sharing!

[Jeroen]

Excellent write up, thanks!
One questions on the pistons. Although symetrical they have sort of two openings? Do they need to be installed with a certain orientation? Some of these piston are a-symetrical (the little ledges on the top, not the piston itself obviously). those typically need to be installed in a specific orientation.

I have a special little tool to get them just right on my Alfa Romeo.

Jeroen

[Gannu_1]

Originally Posted by PatchyBoy

When we are pushing the piston in, we are trying to push the brake fluid back into the master cylinder and will be faced with a lot of resistance. So, we will need to crack open the bleed valve, attach the plastic pipe to the nozzle and drain the fluid into a bottle.

Hey, how about opening the cap of the brake fluid reservoir instead, while trying to push the pistons back? Or do you still need to open the bleed valve?

Excellent DIY!

[PatchyBoy]

Originally Posted by Jeroen

Excellent write up, thanks!
One questions on the pistons. Although symetrical they have sort of two openings? Do they need to be installed with a certain orientation? Some of these piston are a-symetrical (the little ledges on the top, not the piston itself obviously). those typically need to be installed in a specific orientation.

I have a special little tool to get them just right on my Alfa Romeo.

Jeroen

The orientation is not specific on this car. Those two V shaped slots you see on the top of the piston are for the tool that is used for pushing these pistons back.

Originally Posted by Gannu_1

Hey, how about opening the cap of the brake fluid reservoir instead, while trying to push the pistons back? Or do you still need to open the bleed valve?

Excellent DIY!

Thanks. Opening the brake fluid reservoir can also be done. I prefer to drain, refill and bleed due to two main reasons - firstly, keeping the reservoir open and exposed to ambient moist air for extended durations is not a good idea and secondly, there is always a possibility of the fluid being pushed back overflowing and spilling onto painted parts. Brake fluid is very corrosive and getting it on painted parts is not a good thing. I personally felt that draining and refilling is less messier.

[techn0l0gist]

Originally Posted by PatchyBoy

The orientation is not specific on this car. Those two V shaped slots you see on the top of the piston are for the tool that is used for pushing these pistons back.



Thanks. Opening the brake fluid reservoir can also be done. I prefer to drain, refill and bleed due to two main reasons - firstly, keeping the reservoir open and exposed to ambient moist air for extended durations is not a good idea and secondly, there is always a possibility of the fluid being pushed back overflowing and spilling onto painted parts. Brake fluid is very corrosive and getting it on painted parts is not a good thing. I personally felt that draining and refilling is less messier.

Another quick non-messy method is to use a syringe to suck the brake fluid from the reservoir so that it doesnt spill, and then use a C-Clamp to push the piston back in .

[PatchyBoy]

Originally Posted by techn0l0gist

Another quick non-messy method is to use a syringe to suck the brake fluid from the reservoir so that it doesnt spill, and then use a C-Clamp to push the piston back in .

Yes. That would be the ideal way, if one doesn't want to change brake fluid. The C clamp method will not work for the rear brakes of this car. The piston needs to be screwed in and not just pushed in.

[devarshi84]

OT: I have a question. Why is the package marked MOPAR? Isn't that a Chrysler division? Or is Fiat integrating both operations?

ALso what's the size of this disc brake"?

[PatchyBoy]

Originally Posted by devarshi84

OT: I have a question. Why is the package marked MOPAR? Isn't that a Chrysler division? Or is Fiat integrating both operations?

ALso what's the size of this disc brake"?

Mopar is the parts, service and customer care organization within Fiat Chrysler Automobiles.

The rear brake disc for this car is 251 mm x 10 mm

[sandeepmohan]

Originally Posted by PatchyBoy

strangely, that is how long the rear brake pads last in this car, while the front lasted over 50000 kms.

I don't have the confidence to do something like this, primarily due to the lack of all the correct tools required for the job.

My brakes are still good at 41000km. However, I don't want to land up in the same situation. Good, reliable brakes are an absolute must. I have ordered Brembo brake pads (Front and rear) and front rotors from Laxmikant and Company, Goa. Unfortunately; they don't have rear rotors so I am picking up a stock rotor.

Compared to the prices on 99rpm, the difference between stock and Brembo's is not too much. The difference being Rs. 1600 for the rotors.