Front Brakes Uneven wear side to side

[96Formula6sp]

Hey guys asking for some help with some very uneven brake wear on our lemons car. The last two sets of pads have had some uneven wear side to side. Our current brake setup is a set of 79 Dodge Magnum Brakes on 73+ Dart spindles. Anyways our first race we sway some uneven wear. First race the Drivers side front brake had about 1/8th of pad when we swapped. The passenger side was about 1/3 of pad material left. This was after about 2 hours of testing and 10.5 hours of race time. We checked them at 2 hours and wear was even side to side with maybe 1-2mm of pad gone. Using G-loc r16 pads.

Our second set of pads went on at the CMP event however we had some clutch issues with the Ar-5. Anyways they ran some CMP and Barber. At the end of Barber the drivers side pad was gone. There was probably nothing left when I went out with 1 hour 45 mins to go. Fast forward to last weekend were we were putting some new pads and rotors on the car for an up coming test day for the new engine. These were the pads I took out of the car. Probably have close to 16 race hours on this set. They were due for a change but we forgot while fixing other bits of the car.

Drivers side left passenger right.

Outer pad. Hard to see. Passenger side on left drivers on right. Backing plates are on the outside. And yes I know the shim is on the wrong side of the hold down bracket.

Inner Pads. Passenger on left drivers on right.

So we are curious what could be causing this. Are these cars biased towards the drivers front. We took the brackets off as they came from an Ohio car. The inner pad was sticking some on both side. A light file got the area flat again and they pads are free to move. Was thinking it could have been a sticking issue but the passenger side was the worst on the light sticking of the pad. We are not using the anti rattle o-rings. Debating if the brake proportioning valve is stuck. Calipers have two races on them as well as the soft lines.

I will say that I ran the car at the Barber race and was first out. Cars braking was pretty straight. It will wonder some but no issue on fresh pads. I was the last one out and the car was pulling left very hard under braking. Granted I was using the brakes as little as possible but still when on them it would tug to the left due to the uneven pad wear.

Any ideas or things to look into.

 

[67belvedere/225]

so one side wearing ore than other , i would suspect brake hose holding some pressure ,replace both
and what kind of brake fluid you using by the way?

 

[multimopes]

If it was a street car, I would be thinking one caliper was dragging a bit. I would take a temperature gun and aim it one side and then the other to confirm the difference.

 

[67belvedere/225]

i was assuming the callipers where new , good on you multimopes

 

[multimopes]

My other thought was if it was circle track; ("turn left Jim-Bob, turn left"); anyway, I would think the outer wheel (right side when turning continually left) would be doing more work due to centrifugal force making that side of the car heavier and therefore a bigger load on it! But I'm just tilling at windmills here!

 

[multimopes]

By the way, I noted in your first thread that it's a lemons car. I hope you meant "Lemans" because there ain't no Mopar Lemons! LOL

 

[96Formula6sp]

so one side wearing ore than other , i would suspect brake hose holding some pressure ,replace both
and what kind of brake fluid you using by the way?

Soft lines are new. When we did the brake swap it required new lines. Just some rubber ones from the parts store but they get the job done. Using Motul RBF 660 Dot 4. Might be a little over kill tho. Could probably get away with the 600.

If it was a street car, I would be thinking one caliper was dragging a bit. I would take a temperature gun and aim it one side and then the other to confirm the difference.

Car no longer has a tag on it as driving it on the street a one every few months was rare. Could check. In the air both feel the same. I figured if it was dragging it should do it all the time. I would say the first 1/4 of pad wear its even.

i was assuming the callipers where new , good on you multimopes

Two remans that went on our first test day. Ones we got with the brackets leaked out of the bleeder holes. That Ohio rust. One will be getting rebuilt as the passenger side piston is starting to crack. Will run the test day and a new one reman will go on. Think its under warranty from the parts store.

My other thought was if it was circle track; ("turn left Jim-Bob, turn left"); anyway, I would think the outer wheel (right side when turning continually left) would be doing more work due to centrifugal force making that side of the car heavier and therefore a bigger load on it! But I'm just tilling at windmills here!

Its lemons we like to turn both ways. We have run Carolina Motorsports park and Barber Motorsports Park(declassing that joint)

By the way, I noted in your first thread that it's a lemons car. I hope you meant "Lemans" because there ain't no Mopar Lemons! LOL

Nope its a lemons car. Races in the 24 hours of Lemons series. Might take it to the 24 hour of VIR next year with Champ Car.

 

[67belvedere/225]

i built my own , you can get pistons and seal from rock auto and also can get the ceramic pistons when i did mine

 

[MoparLeo]

Race cars don't use factory brakes or lines. Maybe time to upgrade ?

 

[multimopes]

Thanks for the clarification. However, speaking of (remanufactured) calipers, we put some Reman (Power stop) calipers on my son's Jeep last year. Wow, powder coated red and real pretty along with new drilled and slotted rotors and heavy duty ceramic pads. Long story short, after 9 months of use the one side was dragging so bad, I measured the temp on one side at 123 degrees, the dragging side was over 500 degrees! I called about the warranty and found it was only 90 days! It was shortly thereafter that I was watching a brake video on You tube and they mentioned don't waste your money on rebuilt and remanufactured calipers as the failure rate was very high! Not saying yours are but there is that possibility!

 

[96Formula6sp]

i built my own , you can get pistons and seal from rock auto and also can get the ceramic pistons when i did mine

We rebuilt the ones from Ohio that leak. They are around somewhere. Super easy to rebuild. Anyways it is on the to do list. Granted I think I can get them as cheap as $15 a side from the local parts store. So is it worth the time. Will say the one with the ceramic piston is cracking some on the one edge. So will be replacing that one for sure. Thinking metal pistons will be better anyways.

Race cars don't use factory brakes or lines. Maybe time to upgrade ?

Well its lemons so Brakes are open. Kinda why we are using the bigger Magnum brakes. We are going to be running Road Atlanta in December. With the cars new engine the top speed should be around 130mph. Coming into 10a that might be a problem lap after lap. Idea is to move to 17s or 18s and get a 275 under the car. Then it will probably be a homemade kit to get a bigger brake kit. Most of the after market units still want to fit under a 15 inch wheel. We want something with a 13inch or bigger rotor. Granted if we still have the issue of the uneven brake wear big calipers and rotors are not going to fix that issue. Ideas have come from the pick and pulls where modern mustangs, camaros, 300s, chargers and even a challanger or two have showed up. They all have some nice size calipers. Shoot just looked and there is a 2014 Dodge Charger Police car. Seems it has 4 piston calipers and 13.5 inch discs. Might be a good upgrade. Might just have to look around for something.

 

[96Formula6sp]

Thanks for the clarification. However, speaking of (remanufactured) calipers, we put some Reman (Power stop) calipers on my son's Jeep last year. Wow, powder coated red and real pretty along with new drilled and slotted rotors and heavy duty ceramic pads. Long story short, after 9 months of use the one side was dragging so bad, I measured the temp on one side at 123 degrees, the dragging side was over 500 degrees! I called about the warranty and found it was only 90 days! It was shortly thereafter that I was watching a brake video on You tube and they mentioned don't waste your money on rebuilt and remanufactured calipers as the failure rate was very high! Not saying yours are but there is that possibility!

This is true. I have had decent luck over the years. The only car that I did not was a CRX where after some used calipers and remans we found that the caliper itself had clam shelled. Granted I was having the issue of not being able to put on new rotors and pads. Either way after the 4th set I was able to get new brakes on that car.

Could be a caliper issue but I am ok with remans. I know that coming in off track we are pretty even. Usually no smoke or anything. Figure temps on track are in the 400-500 degree range.

 

[MoparLeo]

Brakes from the 70's really don't cut it for modern performance. The whole brake system not just calipers, are what make modern brakes perform.

 

[67belvedere/225]

ceramic is cooler won't make brake fluid want to boil

 

[Ranger16]

I've always notice that the inner pads wear a just a little more than the outers. I suspect that is because the piston pushes directly on the inner pad. IF the slide pins are not lubed well, dried out, rusty, dirty or dragging in the slightest bit, that wear will be exaggerated even more.

 

[96Formula6sp]

Brakes from the 70's really don't cut it for modern performance. The whole brake system not just calipers, are what make modern brakes perform.

This is true. It however does get the job done. Car has been reliable in the stopping minus this pad wear issue. Considering it is around 3500lbs with driver and a full tank of gas. Yeah its not 2000lb car. We could probably get another 100lbs out of by cutting the underside of the hood and trunk lid out. 1970s brakes still suck but with the brake fluid and $250 sets of custom pads the car seems to be ok.

We want to upgrade anyways as we are using 245/40/15 tires. They are what we consider Miata size. There are no tall 15 inch 200tw tires available. We had 15s so we bought these. So we will be buying bigger rims to get a bigger and wider tire. At a 22.7 inch and would like something in the 25.5 inch range. Granted the small tires cheated up the 2.76 rear end. With the new engine that might hurt us some.

 

[96Formula6sp]

I've always notice that the inner pads wear a just a little more than the outers. I suspect that is because the piston pushes directly on the inner pad. IF the slide pins are not lubed well, dried out, rusty, dirty or dragging in the slightest bit, that wear will be exaggerated even more.

Ours do not have the slide pins. Ours slide against the bracket itself. Using the later Cordoba, Magnum Brakes. Ours came off a 1979 Dodge Magnum.