Hi chaps,

I currently have a mk indy which is based on a 1983 sierra.

Currently the setup is single piston disks at the front and drums on the rear.

Now I have bled the system with new fluid and it has new clippers, and now even a new master cylinder on the brake pedal (at a cost of about £80!) however it still feels like it stops like a freight liner, I mean I can lock up if I stamp it down, but ild like to have this sort of braking with much less effort!

My question is - how easy is it to change the front callipers to something with a little bit more bite, and what do I need to do to change my rear drums to a disk set up.
It seams like it will be a fairly big task at a glance? Are there any ford parts that I can use to do this conversion.

My ideal world would be for someone to say - yes the ford "...." callipers will bolt straight onto the front, in place of the old callipers, and the rear disks from the ford "..." Will bolt straight onto the rear of the car, with this modification plate that you can buy here "..." However I know it's not going to be like this!

Can I use front callipers from a doner car for both the front and back, like find 2 ford "...." And take both sets of front callipers from both cars and fit one set to the front of the car and one set to the rear (as I know how much more bite front callipers usually have, plus I think it would look better?)


Sorry to sound like a complete flop, but I don't even know where to start! I'm 20years old with fairly good mechanical knowledge (my job is mechanical too) so I'm hoping it won't be too difficult!

I'm looking to do this as cheap as possible!?! And I really do mean as cheap as possible! Haha

Thanks again for your help!

If it's Sierra running gear surely the Sierra 2WD Cosworth brakes will fit, vented discs and callipers up front and solid discs and callipers at the rear.

The thing is without a servo you need to get used to pressing the brake pedal quite hard.

On mine I replaced the fronts with a Wilwood 4 pot kit from Rally design.

Used xr4 10 inch drums on the back. All good.

I would do the fronts first as I found the improvement over the standards calipers was very good.

Thing with discs is they can tend to over brake on a light car and you then need a bias valve or bias bar pedal box to compensate. I'm sure someone will rubbish that in a minute tho.

Good luck!
Steve

[Edited on 31/7/14 by coozer]

To improve pedal feel pedal ratio and Master cylinder size are the easiest cheapest options.

Before you change stuff and spend lots of money get some decent front brake pads and make sure the rear brake shoes are adjusted correctly .the brakes on your car are more than upto the job as your is approx 50 or 60 percent of the original donor car.

It'll be the lack of a servo that makes it feel under-braked. I kept the servo and feel my braking is very good. I use the disks and calipers from a 2l Sierra on the front and the 8" drums from a 1.6l Sierra on the back. I remember from SVA that it gave a good balance, with less chance of locking the rears first than the 9" drums or the rear disks from a 2l.

if you haven't got them then fit mintex 1144 pads to the front - you will be amazed how much better the brakes are.

They will still need a good shove but they have good initial bite and you will have a lot more confidence in them

"To improve pedal feel pedal ratio and Master cylinder size are the easiest cheapest options."

"Before you change stuff and spend lots of money get some decent front brake pads and make sure the rear brake shoes are adjusted correctly .the brakes on your car are more than upto the job as your is approx 50 or 60 percent of the original donor car."


fully agree..its not necessary changing anything....try to investigate where the problem in your car is located...you might have only a wrong sized master cylinder...or a wrong lever ratio at the pedal-box.

those 2 things need to be checked first.

can you post a pic of your master and do you know where it comes from?

To change drums to disc you need a hub bracket that provides a caliper mount
Then I am led to believe that Sierra rear discs just fit on with the matching calipers and pads
You may need to revise the handbrake cable

One of my mods to make the brakes better , was to move the pivot pin on the peddal up about 12mm, thus increasing the leaverage, then four pot calipers,

much nicer now !

Brakes 101
Fact (1) because it is longer the Sierra brake pedal has nearly 3 times the leverage ratio of the the brake pedal in your car.
Fact (2) the brake servo boost on the Sierra provides 60% of the force applied to the master cylinder.
Fact (3) because of weight transfer on front engined rwd car the rear brakes can only contribute at most 30% of the braking.
Fact (4) drum brakes have an inherent self-servoing effect at the low end of the applied force range.
Fact (5) 9" Sierra drums were more than adequate for a vehicle of the Sierra's weight.
Fact (6) standard after market brake pads are very variable in friction performance.




If you put the above together you will see that with a car less than half the weight of Sierra you will to apply to 3 to 4 times the force to the brake pedal to achieve the same deceleration as the Sierra.
So how to fix the problem? The easiest options are :
(1) fit front brake pads with more suitable friction characteristics. Mintex M1144.
(2) Change the master cylinder to one with a more suitable (smaller) bore.
(3) Both of the above

These aren't the only options you could fit a servo, fiddle with the pedal leverage ratio or fit massive front discs and callipers with bigger effective hydraulic area but option (3) is relatively simple and cheap.



[Edited on 31/7/14 by britishtrident]

quote:

---

Originally posted by Shaunk10
Hi chaps,

I currently have a mk indy which is based on a 1983 sierra.

Currently the setup is single piston disks at the front and drums on the rear.

Now I have bled the system with new fluid and it has new clippers, and now even a new master cylinder on the brake pedal (at a cost of about £80!) however it still feels like it stops like a freight liner, I mean I can lock up if I stamp it down, but ild like to have this sort of braking with much less effort!

My question is - how easy is it to change the front callipers to something with a little bit more bite, and what do I need to do to change my rear drums to a disk set up.
It seams like it will be a fairly big task at a glance? Are there any ford parts that I can use to do this conversion.

My ideal world would be for someone to say - yes the ford "...." callipers will bolt straight onto the front, in place of the old callipers, and the rear disks from the ford "..." Will bolt straight onto the rear of the car, with this modification plate that you can buy here "..." However I know it's not going to be like this!

Can I use front callipers from a doner car for both the front and back, like find 2 ford "...." And take both sets of front callipers from both cars and fit one set to the front of the car and one set to the rear (as I know how much more bite front callipers usually have, plus I think it would look better?)


Sorry to sound like a complete flop, but I don't even know where to start! I'm 20years old with fairly good mechanical knowledge (my job is mechanical too) so I'm hoping it won't be too difficult!

I'm looking to do this as cheap as possible!?! And I really do mean as cheap as possible! Haha

Thanks again for your help!

---

quote:

---

Originally posted by Shaunk10

I currently have a mk indy which is based on a 1983 sierra.

---

quote:

---

Originally posted by Shaunk10
Hi chaps,

Currently the setup is single piston disks at the front and drums on the rear.

---

quote:

---

Originally posted by Shaunk10

Now I have bled the system with new fluid and it has new clippers, and now even a new master cylinder on the brake pedal (at a cost of about £80!) however it still feels like it stops like a freight liner, I mean I can lock up if I stamp it down, but ild like to have this sort of braking with much less effort!

---

quote:

---

Originally posted by Shaunk10

My question is - how easy is it to change the front callipers to something with a little bit more bite..
!

---

quote:

---

Originally posted by Shaunk10

, and what do I need to do to change my rear drums to a disk set up.
It seams like it will be a fairly big task at a glance? Are there any ford parts that I can use to do this conversion..

---

quote:

---

Originally posted by Shaunk10

My ideal world would be for someone to say - yes the ford "...." callipers will bolt straight onto the front, in place of the old callipers, and the rear disks from the ford "..." Will bolt straight onto the rear of the car, with this modification plate that you can buy here "..." However I know it's not going to be like this!

---

quote:

---

Originally posted by Shaunk10

Sorry to sound like a complete flop, but I don't even know where to start! I'm 20years old with fairly good mechanical knowledge (my job is mechanical too) so I'm hoping it won't be too difficult!

---

quote:

---

Originally posted by Shaunk10


I'm looking to do this as cheap as possible!?! And I really do mean as cheap as possible! Haha

---

I'm very happy with the brakes on mine and never find them wanting. On the track days I've done I just haven't noticed the brakes, which tells me they are spot on.

I have a totally standard Sierra disk/drum set-up except for a 19mm Fiat 124 master cylinder [Sierra CVH m/c is 22mm] with the pivot on the pedal changed slightly to give a bit more leverage and EBC yellow stuff pads. The total cost being about £55.

I can easily lock the wheels from cold and they just get better as they warm up [not that they warm up much as the vented 240mm disks aren't ever working very hard stopping such a light car]

Obviously this assumes your sierra brakes aren't knackered to start with.

Unless you are making a lot of power there is no need to do any major brake upgrades, unless you want the bling factor!

Stu

quote:

---

Originally posted by britishtrident
Brakes 101
Fact (1) because it is longer the Sierra brake pedal has nearly 3 times the leverage ratio of the the brake pedal in your car.
Fact (2) the brake servo boost on the Sierra provides 60% of the force applied to the master cylinder.
Fact (3) because of weight transfer on front engined rwd car the rear brakes can only contribute at most 30% of the braking.
Fact (4) drum brakes have an inherent self-servoing effect at the low end of the applied force range.
Fact (5) 9" Sierra drums were more than adequate for a vehicle of the Sierra's weight.
Fact (6) standard after market brake pads are very variable in friction performance.




If you put the above together you will see that with a car less than half the weight of Sierra you will to apply to 3 to 4 times the force to the brake pedal to achieve the same deceleration as the Sierra.
So how to fix the problem? The easiest options are :
(1) fit front brake pads with more suitable friction characteristics. Mintex M1144.
(2) Change the master cylinder to one with a more suitable (smaller) bore.
(3) Both of the above

These aren't the only options you could fit a servo, fiddle with the pedal leverage ratio or fit massive front discs and callipers with bigger effective hydraulic area but option (3) is relatively simple and cheap.

---

To convert from Drums to Discs is a relativity straightforward job, which does not involve changing the rear axle.

What you need as previously said- is the caliper mounting bracket which bolts to the drum brake bearing carrier as per below pic - remove drums and back plate fit bracket.



[img]
Rear Caliper Bracket [/img]

Once a bracket has been fitted you can fit standard Sierra Discs and Handbrake calipers pic below or use a Wilwood Kit.


[img]
Rear Brakes [/img]

Thanks a bunch to everyone , only just been able to get back to a computer, I think I will try the pad upgrade first and see how that improves, iv funnily enough just gone from 15s down to 13s in wheels size and the drivability is much more improved, as well as this I'm thinking of getting some yokohoma tyres to suit the wheels. Ild imagine this would help a fair amount when braking?

Cheers again chaps