Caliper refurb - how to ?

ChrisPR

ChrisPR

Daily Driver
Hi all,

I have these Uno Turbo front brake calipers that I need to refurbish before I put them on the X. I'm after any advice that others can offer on how to do this, what products are best etc.

I'm guessing that blasting the bigger components is a good idea (I have access to a small blast cabinet .. yay) but how would I protect the surfaces that need to be protected (like the inside bore of the caliper) ?

Any thoughts or recommendations ? Also, I'm not sure whether the pistons and/or bores are beyond repair - it's hard to get that kind of detail into the photo's to show what they're like.

Click to enlarge ...





 
These calipers allow the use of vented disks, right?

Probably worth saving then, IMO. You can blast the outside of them, but as you state, don't expose the piston and bore. Look for a large rubber "plug" that is kind of like a cone with the tip cut off. Check with laboratory supply places, and don't hit them with the blast gun too hard. They also sell smaller ones used to block off small holes when powder-coating, (I got some from Eastwood) so you might also check with a local powdercoater.

As far as the bores, it's hard to tell but if they are pitted, you could mildly overbore them to a slightly larger size and find pistons from another application that fit, or have new pistons machined to your specification, it should not be a difficult task on a lathe. Better to find a slightly larger application though, so the bore seal is easily obtainable. Or if the overbore was a very small amount, say .010 total diameter, the stock bore seal may work with custom pistons.

Pete
 
Thanks

I was curious how the Uno Turbo brake swap would affect front/rear bias. With X1/9 stock also being 48 mm in the front, I guess this is not a concern.
 
I kinda agree with Pete... but haveta ask...

My car always had a problem INITIALLY with front wheel lock up...

With no real added weight and a power increase I can only assume to be rather minimal... Why are you upgrading to a larger caliper? Will you be doing SCCA track racing or is this a street car?

Outside of looks, I believe with the proper rake, tires, tire pressure and possibly a porportioning valve, the stock disc and caliper should be more than adequate for the street.

Not judging here... just inquiring...
 
You can get a rebuild kit and hoses of Laursen in Denmark

http://laursen-online.dk/x1-9/

You can blast the caliper, i mounted the pistons on the lathe and polished them, don't lose the pins they are a pain in the ass to find.

I nickel plated mine:

FrontBrake.jpg


Here are the rotors:

VentDisc.jpg
 
Black-Tooth said:
Outside of looks, I believe with the proper rake, tires, tire pressure and possibly a porportioning valve, the stock disc and caliper should be more than adequate for the street.
Click to expand...

The Uno Turbo setup allows for a vented brake disc (rotor) which will help performance, but most importantly it has an improved sliding mechanism which doesn't have the metal wedges that have to be greased every so often.

Once the motor (also U/T) is finished and installed it would be nice to have confidence that the brakes are in top form :)
 
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Believe it or not

I knock off all the rust and scale with a wire wheel on a bench grinder. You can get in all the corners if your patient (and take the safety crap off the grinder)
 
I'm with you.

Possibly the front wheel lock up is the tires we are running. I have Pirrelli P6000 on the car and they are a sticky tire. Pounce on the brakes a bit to hard and my fronts lock up and I am running dual Rads with more coolant as well, both out front way past the front axle.

I keep seeing guys on the form wanting to up grade the front brakes. Since my fronts lock up my thought is the rears should be upgraded.

What are we missing?

TonyK.

Grimsby Ontario Canada.
 
Well, repeated use is what I think you are missing...

TonyK said:
I keep seeing guys on the form wanting to up grade the front brakes. Since my fronts lock up my thought is the rears should be upgraded.

What are we missing?

TonyK.

Grimsby Ontario Canada.
Click to expand...

Sure, the front brakes lock up the first time you stomp on them. What about the 100th? In a repeated hard use situation such as road racing or canyon carving, brake fade will set in due to the stock systems inability to dissipate heat. By going with a larger and/or vented rotor (aka heat sink), you extend the systems capability for repeatable, predictable brake behavior.

Is it overkill for a street car? Maybe. But if you were to buy, say, a new Corvette, you would want enough reserve in the brake system to use it on track days. What's wrong with wanting the same thing for our X's? :D

Pete
 
Did an auto cross.

When I was doing the auto cross all through the runs the fronts kept locking up. I must be a timid driver compared to the rest out there that want this upgrade, just never got to the point where the brakes fell short. I don't see the need, but for the others go for it as your driving requires it.

Thanks for the reply.

TonyK.

Grimsby Ontario Canada.
 
It's not about braking power for me

It's about brake fade, unventilated discs are far more prone to fade as they cannot dissipate the heat as quickly.
 
I've never autocrossed...

TonyK said:
When I was doing the auto cross all through the runs the fronts kept locking up.
Click to expand...

But it looks darn fun. I bet you get a lot less seat time than a track day though, cuz it looks like the average autocross course takes about 2 minutes to complete, with plenty of cooldown time in between rounds. On a good day at the track (that's one where the car doesn't break) I get 7 sessions at 16-18 minutes "green flag" time each. On an 11-turn, 1.8 mile road course (Hallet), you will discover the limitations of the stock brake system in 16 minutes. Sometimes the hard way. :eek:mg:

Pete
 
Pete... its probably 'cause us TONYS are...

... both kinda OLD and only use our brakes as a LAST RESORT anyway...

HA!

But I have run my car pretty hard over the years and brake fade has never been an issue for me... probably 'cause they work so well initally when I'm on and off them quickly.

I have also pretty much solved any and ALL lock-up issues with the several things I mentioned earlier... and they are just working very efficiently.

Vented and slotted rotors do indeed have their place and have proven their worth... Just speaking here from my FRUGAL and PRACTICAL perspective, I guess...
 
I'm confused...

Isn't the X a momentum car...?

Why are you stomping on the brakes? I barely touch the brakes while racing, just a tap to set the front then hard on the throttle. I guess thats why I still have my 4 year old set of Panther + pads.
 
I guess it depends on the track...

Rooster said:
Isn't the X a momentum car...?

Why are you stomping on the brakes? I barely touch the brakes while racing, just a tap to set the front then hard on the throttle. I guess thats why I still have my 4 year old set of Panther + pads.
Click to expand...

If you have a lot of long sweepers, what you say certainly makes sense. But Hallet is 11 fairly sharp turns, and when I am going at it hard, there is only 1 area on the racetrack (turn 6, the carousel) where I am at partial throttle. Everywhere else, it's hard throttle or hard brakes. My car handles well, but it does not take the 90 degree turn 1 at the 110 or so I am doing at the end of the main straight! :eek:mg:

Pete
 
Pete Whitstone said:
If you have a lot of long sweepers, what you say certainly makes sense. But Hallet is 11 fairly sharp turns, and when I am going at it hard, there is only 1 area on the racetrack (turn 6, the carousel) where I am at partial throttle. Everywhere else, it's hard throttle or hard brakes. My car handles well, but it does not take the 90 degree turn 1 at the 110 or so I am doing at the end of the main straight! :eek:mg:

Pete
Click to expand...

This is where I race. This and cone dodging. I very rarely hit the brakes and the front straight speed is about 85mph.

http://img532.imageshack.us/img532/405/beevk3.flv
 
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