34 replies to this topic

[JRHille]

Just installed new front calipers with clips and springs, made sure the slides were greased and all. I did leave the old pads, waiting for new ones to come in a few days. I still have a significant amount of drag only on the right front wheel. I can't spin it more than a few inches without constant pressure on the wheel.

The brakes were acting funny during the last race weekend, one or two turns a lap the pedal would go down much farther than normal. So I replaced the master cylinder as well.

The inner pad on the side that's dragging is worn almost twice as much as the outer, and they're both down to about nothing. Also noticed the pad compund was wearing at a slight angle. For the life of these pads I was not using the caliper clips.

Could the proportioning valve be bad? Wouldn't that also affect the rear brakes? (the rears have no drag). Could my spindle be slightly bent? Or maybe if I put fresh pads on it will fix the problem?

I don't want to have to replace everything, just hoping the pads will fix the issue. Any other ideas?? Would rather replace the proportioning valve before the spindle if that is more likely.

[FTodaro]

When you did the calipers who's did you use. I went through a bunch of NAPA calipers they were all crap.

Also did you only replace the caliper and not the bracket that it bolts too? Sometimes they get beat up, not likely but check it with the other side make sure it did not open up.

Drago has some good calipers that he does that is where I ended up.

[Glenn]

Put the new pads in and see. If the old pads are as bad as you say they are not "flush" with the rotor and could very well be causing the drag.

[Muda]

Drago has some good calipers that he does that is where I ended up.

Did you file/clean up the pads and the brackets?

[JRHille]

Frank- I used Drago's calipers, brackets and all.

I'll see if the new pads fix the issue, thanks guys. If not, next step?

[JRHille]

I did not file down anything, I'll make sure to do that as well.

[Jim Drago]

what pads are you using?

[Nsparks]

I'll see if the new pads fix the issue, thanks guys. If not, next step?

Give the car to me as it is clearly unfixable. I will see to it that the whole chassis is melted down.

[JRHille]

Jim- Carbotech XP-10's

Nate- Make sure you lock all your stuff at Mid-Ohio....

[Jim Drago]

Justin
See it sounds like something is olding pressure on the caliper? Not releasing brake pressures. Check free play on pedal, matser and prop valve
Jim

[JRHille]

The only issue I am having is on the right front caliper, master cylinder was just replaced. Should I try bleeding the cylinder again?

[davew]

On any caliper that is painted or powder coated, which I think Jim's are, you need to remove the coating from any sliding surface. You also need to remove the coating from any bolt flange surface. Like under the bolt heads on the caliper bracket and also on the spindle side of the same bolt hole. Powder coating is worse than paint for this area. When it gets hot it will get soft, allowing the bolts to come loose.

I have seen this on new calipers with new bolts, The bolts are bent. While unscrewing the bolts, watch the caliper for movement caused by a bent pin. Replace the pins as needed.

If you have hydralic problems you can diagnose by simply opening the bleeder screw and see if the problem goes away. If pressure is remaining in the system, opening the bleeder will remove the pressure, thus allowing free spin.

I don't know about Carbotech's but Cobalt pads are designed to used without anti rattle clips. Hawks have a tendancy to have drips of paint on the slide tabs.

It is this type of attention to detail that seperate a front running car from a midpacker.

Dave

[Keith Novak]

I would definately look for the problem rather than hope new pads make it go away. I had something very similar happen last year that got progressively worse. The pads wore at a severe angle front to back and the braking performance was awful. When they wear like that, they wear VERY quickly. I chewed up a set of carbos in 6 sessions and parts of them were cracking off in chunks. Not only could just about anyone out-brake me, it tended to lock up that wheel too and was murder on tires. That gets expensive. I sent mine off as cores when I bought new ones from Jim so I never found out what was wrong but it was a big enough issue that I essentially replaced my whole brake system to make sure it went away.

[Muda]

Jim's bolt flange surfaces are clean but you have to clean up the brackets in the slide area, especially if you're not using the clips.

[JRHille]

This is why these forums are great and why the class is awesome.

It might be worth noting that I had the same drag issue on that corner before I changed calipers, master cylinder, etc. I don't think it got any worse but definitely not any better. I will try to do all of these things thanks guys

[KentCarter]

The 'clips' are actually the bearing surfaces in which the pads slide. Without them, the pads can hang up and drag.

[Bench Racer]

As Wheeler indicated isolate the mechanicals form the hydraulics. Also isolate the hub bearings from the brake system. Take the pads out & spin the wheel.

Did you use synthetic grease?

[JRHille]

Yes used synthetic grease.

The car is loaded up on the trailer right now but I will do more troubleshooting on Friday. It has been dragging like this for a while so if I can't fix it before the race I'm not losing anything....

[JRHille]

Hub spins perfectly with the pads out

[Muda]

Something's bent