Dan's Brake Thread

[bordin34]

Should I get my rotors cut? I am in the process of replacing the master cylinder, calipers, pads, and all rubber hoses. IS there a general rule of thumb about when they should be cut?

[The70RT]

You mean turned right? I would do it when the outer edge is noticibly thicker than the mating surface unless you have grooves or warping. Most garages do it everytime for extra money or they want to make sure the customer doesn't come back on the job they just did. If you were doing it on a car with cheaper rotors sure get them turned or replace them. These rotors on Chargers are not cheap. 80-120 last I checked. Dodge Dakota 30 bucks. Dodge neon 15.

[resq302]

I would have them machined / turned / cut (whatever you want to call it)  for a couple of reasons.  First, anytime I put new pads on, I get them machined so the pads do not wear unevenly or get a premature groove in them.  Plus it also makes for better braking performance.  Secondly, it looks like there is either grooves worn into them or that you have glazing on the rotor.  Glazing is mirror-like reflection on the rotor caused by the heat and metal being worn smooth.  A glazed rotor will not stop a car that well.  Imagine trying to hold onto a nicely waxed car, well, that is the same thing your pads will be doing to a glazed rotor.  Finally, machining the rotors will remove any slight warpage that you might have. Granted, making the rotor thinner will add to it possibly warping, but the amount they take off ususally will not contribute significantly to excessive warping or pedal pulsation.  If your brake pedal pulsates when you hit the brakes, (like getting a foot massage) then chances are your rotors are warped and need to be machined.

The scary thing is that most dealerships or service places do not cut or machine rotors and drums anymore.  They would rather charge you the extra money to replace them instead of cutting and resurfacing the old salvageable drum or rotor.

For what its worth, if it was my car, I'd have them resurfaced and throw a new set of pads on there.  Also, while you have the rotors off, pull the bearings and inspect them and pack them with some new grease.  A little preventative maintenance now will save you a lot down the road.

[bordin34]

Thanks, I will call around and ask how much places are charging.

[resq302]

I want to say they are about $15-20 per rotor to be machined, or at least they used to be.

[Steve P.]

Always resurface the drums or rotors when replacing the shoes or pads.. New surface to new surface. You want ALL the contact surface you can get and you damn sure don't want to put new brake material against a glazed steel surface.

[rt green]

have them measured. there is a minum spec. if you are going to keep the car, new is always best. brakes are not the place to be worried about saving a buck or 2.

[bordin34]

Today I removed both calipers and disconnected the hoses. I think I need new wheel bearing because if I grab to top and bottom of the caliper and pull and push hard I can hear/feel slight movement. Tonight I am going to remove the calipers and Master Cylinder.

[The70RT]

Today I removed both calipers and disconnected the hoses. I think I need new wheel bearing because if I grab to top and bottom of the caliper and pull and push hard I can hear/feel slight movement. Tonight I am going to remove the calipers and Master Cylinder.

I would clean the bearings with solvent & inspect them, but the play is adjusted with the nut that holds the rotor on.

[bordin34]

Does anybody know which way the copper washers go on the calipers? Do they go rounded side toward the hose or flat side toward the hose.

[bordin34]

Here are some pictures







And some pictures of when the front clip was replaced a couple owners ago.

[bordin34]

I took the rotors off the spindles today. My only problem is getting the inner wheel bearing out of the rotors. I can't seem to get the seals out and they are blocking the bearing.

[Steve P.]

This is easier than you will think.

With the dust cover, cotter pin and nut removed from the disc hub and spindle, slide the rotor toward you and remove the outer bearing. Now slide the rotor back onto the spindle and replace the spindle nut threading the nut on by about 3 turns. Now just grip the rotor and pull it toward you with some force. This will press the inner bearing and seal off the hub.

To install the  bearing and new seal you will grease the bearings and install the seal by tapping it into the hub in a circular motion. Just lite taps. You can also use a small block of wood between the seal and hammer. Tap the seal until it is flat with the back of the hub. Just a touch of grease on the seal and you are ready to reinstall the works.

Another way is to use a large socket that has an outside diameter just smaller than the outside diameter of the seal.

[terrible one]

So did you end up getting new rotors? With new calipers, pads, and hoses going on, I would go ahead and spring for them if I were you. I used '73 Charger discs on my '68 and can't remember them being very expensive at all . . .

[bordin34]

I am going to see if I can get mine cut and if I cannot I will be getting new ones. They seem to run about $50 each new.

[bordin34]

I tried that way and couldn't get it out. I didn't pull as hard as I could either.

[Steve P.]

Try it again.. It WILL work...

Then again those rotors look like crap.  Try to find rotors made in CANADA.. They are better steel than the junk from over seas..

[The70RT]

Not a problem. Get a hammer and use the handle part. Stick through the rotor in an angle till it hits the bearing and use another hammer and one easy hit and it falls right out with the seal......done deal.

[bordin34]

Thanks, wow that was really easy. I had both out in less than a minute.

[The70RT]

Thanks, wow that was really easy. I had both out in less than a minute.

[bordin34]

I am taking my time on this and have yet another question. Should I get new wheel bearings, the ones I have now look fine and I don't see any cracking or similar stuff. The only thing I see weird with them is I am wiggle them between the races, if that makes any sense. If that is normal, would I be fine to just repack these?

[The70RT]

I am taking my time on this and have yet another question. Should I get new wheel bearings, the ones I have now look fine and I don't see any cracking or similar stuff. The only thing I see weird with them is I am wiggle them between the races, if that makes any sense. If that is normal, would I be fine to just repack these?

You need to clean them in solvent to inspect them for any pitting on the rollers or race. If not they are good to go. New ones are like 20 for 4 if you decide to go that route.

[Steve P.]

If you have a wiggle between your spindle and rotors the bearings are not adjusted properly. There will always be a slight space between the bearings and races, but it should be too slight to ever feel by hand. With a dial indicator you should only see a few thousandths.

Clean and inspect your bearings. If they are good you can reuse them. Just make sure the races are properly set into the rotor. I have seen people end up with too much play in the bearings due to NOT setting the races to full seat.

A good book on doing brakes and bearings should be your next purchase. Remember that brakes are the most important part of the car. If the car doesn't start it probably won't kill you. If it doesn't STOP it damn sure can..

[bordin34]

Ok, I am going to get new bearings. Now I have another question, I am looking for rotors and all the ones I find are listed as 10.98"od I thought they are supposed to be 10.87"od. Would they 10.98" work?

[Steve P.]

I don't know for sure, but I would imagine .110 would not kill ya.. I have seen more rust build up on the outer edge of rotors than that..

Try VERY hard to find CANADIAN made rotors if you are just going with stock replacements. Much less trouble down the road..

[bordin34]

I bought new bearings and rotors and installed them this week and bled the front. While bleeding the drivers side I noticed the grease boot on the upper ball joint was torn, would this pose a major problem, like the joint suddenly popping apart.

[The70RT]

I bought new bearings and rotors and installed them this week and bled the front. While bleeding the drivers side I noticed the grease boot on the upper ball joint was torn, would this pose a major problem, like the joint suddenly popping apart.

As long as your ball joint is tight your ok. You may have to grease it more often because that holds the grease in and the dirt out. If they are original you are probably gonna be replacing them eventually. Then your taking all the brake work back off. Then it is do you replace the lowers?...then pretty soon your doing the complete front end like you will eventually if you plan on keeping the car for a long time 

[bordin34]

I bled my brakes and tested the pedal, it was really soft. So I began thinking, I remembered that while bench bleeding the Master, when I applied pressure fluid would shoot up out of the front reservoir, the one that feeds the rear brakes. Does this mean my Master is bad and not putting any pressure to the rear?

[The70RT]

I bled my brakes and tested the pedal, it was really soft. So I began thinking, I remembered that while bench bleeding the Master, when I applied pressure fluid would shoot up out of the front reservoir, the one that feeds the rear brakes. Does this mean my Master is bad and not putting any pressure to the rear?

I doubt it. I would make sure you bleed the whole system good. New brake fluid and a flushing of the old would be a good idea anyway.

[bordin34]

My dad and I bled the front and I gravity bled the rear. I have all new fluid in the system. I was just thinking that instead of it maintaining pressure on the plug when pushing by hand it was effectively bypassing the pressure somehow  and turning around then squirting back up. I can't really describe it so I tried drawing my thoughts.

[Steve P.]

Even when you have done a perfect brake job on all 4 corners, you will have a spongy feel at the pedal until you burn in the brakes. Make sure your rear shoes are adjusted up and then check your pedal. If you have plenty of pedal take it for a ride and do some test stops before getting very far. I do a series of short 20mph and stop. Then when I know I have a good solid brake system I take it out to where I can do some 35-40mph long gradual stops to burn in all the new brake material.

If you do all that and still think you have a sponge pedal I would start bleeding the system starting at the farthest wheel, (RR), then LR then FR and lastly FL.

With all of this and knowing that all parts are installed right and are in good shape you should be set.

[bordin34]

With the engine off, I just compared the brakes to those on my dad's '97 Mustang and they seemed to pump up just as fast and firm. I think I will still re-bleed the rears just for good measure.

[bordin34]

I am gravity bleeding the rears again and when I filled the reservoir I noticed that the fluid in there was noticeably dirty I don't know how it could happen. I blew out all the lines and put fresh fluid in so I don't know how it could have gotten dirty. All that I am really concerned about now is the fluid squirting up out of the reservoir.

[resq302]

Just because you blew out the lines doesnt guarantee that you got all of the sludge out that might have been sticking on the walls of the tubes.  Might have to run the car for a bit and then power bleed the lines and clean them out again.  I've never really had an issue like this since our cars pretty much always had the brake lines replaced with stainless lines and then just replaced with new fluid.

[green69rt]

I'm resurrecting this thread for one question.  I've always heard that when replacing bearings on a car (front wheel bearings)  that the hubs are NOT packed full of grease.  Bearings are greased correctly, and if some extra grease ends up inside the hub during assembly then that's OK.  But do not pack the hub full.  Which is correct.

[birdsandbees]

FSM says to fill hub even with bearing cups and hand (or pressure) pack bearings. As I did and show in my thread. I always did what you're saying ... until I read the FSM yesterday!   Mind you thinking back to the diagram showing a cutaway hub and what I think was their depicted grease fill I may have overdone it a bit!

EDIT: just did a little googling and I see all the arguing about it for both ways. This guy laid it out pretty good

First, what is grease, and why are its properties important for particular applications? Grease is roughly 90% oil, 5% thickener, and 5% additive packages (EP, R&O, etc). The thickener in grease acts the same as a sponge. Squeeze it, and the oil releases. This is the mechanical release of the lubricating oil from the thickener. Very little grease in or around the bearing is subjected to mechanical working. The other release method is temperature rise, of which all of the grease in most housings is subjected to. It is the release of the lubricating oil and how it travels in the housing that must be evaluated.

After the bearing is packed full, installed, and run a bit the bulk of the grease is channeled out of the bearing. In effect, the bearing will purge what it does not need. This is important since too much lubricant can cause overheating. Think of it like walking on the beach. Is it easier to walk in a thin film of water or water up to your hips? Your feet are still cool in either case. Excess heat generation can occur if too much grease is used and churns in the housing. Most sealed bearings are 1/3 - 1/2 full of grease. High-speed machine tool spindles with grease lubricated bearings only have a 15% fill (that 15% of the available space inside the bearing) of grease, with almost all purged during break in (less than 5% effective.)

On the other side of the coin, if sufficient grease is not available we all know what will happen.

For our applications, the grease can only go two ways after purge, either outboard toward the cap/seal, or inboard toward the hub with the large void space.

Here's where temperature and housing design come into play. If the housing temperature is high, and the hub is spinning fast, and the void space is empty, the purged grease/oil may fling itself into the void space and not ever run back into the bearing.

For many of us packing the bearing full, filling the outboard cap, filling the void space between the cup/cone/washer, and filling the space between the seal and inner bearing cone will be sufficient. Enough additional oil will be released from this excess grease for most normal driving situations. I would however smear grease on the hub interior and hub shaft. This will help to reduce the chances of corrosion and the resultant rust particles from contaminating the bearings. It wont hurt anything to put a large dab in the hub void.

For those of us that push a bit harder, I'd recommend the same as above except to fill the hub void space a 1/3 full. This will allow for additional oil to be available to the bearings during high-heat conditions. I have been running this setup for four years using Pennzoil 707L Red Grease with good results.

Most late-model cars now use integrated hub units where the bearings are integral to the hub. These permanently sealed units are 1/3 - 1/2 full of grease.

[green69rt]

FSM says to fill hub even with bearing cones and hand (or pressure) pack bearings. As I did and show in my thread. I always did what you're saying ... until I read the FSM yesterday!   Mind you thinking back to the diagram showing a cutaway hub and what I think was their depicted grease fill I may have overdone it a bit!

EDIT: just did a little googling and I see all the arguing about it for both ways. This guy laid it out pretty good

First, what is grease, and why are its properties important for particular applications? Grease is roughly 90% oil, 5% thickener, and 5% additive packages (EP, R&O, etc). The thickener in grease acts the same as a sponge. Squeeze it, and the oil releases. This is the mechanical release of the lubricating oil from the thickener. Very little grease in or around the bearing is subjected to mechanical working. The other release method is temperature rise, of which all of the grease in most housings is subjected to. It is the release of the lubricating oil and how it travels in the housing that must be evaluated.

After the bearing is packed full, installed, and run a bit the bulk of the grease is channeled out of the bearing. In effect, the bearing will purge what it does not need. This is important since too much lubricant can cause overheating. Think of it like walking on the beach. Is it easier to walk in a thin film of water or water up to your hips? Your feet are still cool in either case. Excess heat generation can occur if too much grease is used and churns in the housing. Most sealed bearings are 1/3 - 1/2 full of grease. High-speed machine tool spindles with grease lubricated bearings only have a 15% fill (that 15% of the available space inside the bearing) of grease, with almost all purged during break in (less than 5% effective.)

On the other side of the coin, if sufficient grease is not available we all know what will happen.

For our applications, the grease can only go two ways after purge, either outboard toward the cap/seal, or inboard toward the hub with the large void space.

Here's where temperature and housing design come into play. If the housing temperature is high, and the hub is spinning fast, and the void space is empty, the purged grease/oil may fling itself into the void space and not ever run back into the bearing.

For many of us packing the bearing full, filling the outboard cap, filling the void space between the cup/cone/washer, and filling the space between the seal and inner bearing cone will be sufficient. Enough additional oil will be released from this excess grease for most normal driving situations. I would however smear grease on the hub interior and hub shaft. This will help to reduce the chances of corrosion and the resultant rust particles from contaminating the bearings. It wont hurt anything to put a large dab in the hub void.

For those of us that push a bit harder, I'd recommend the same as above except to fill the hub void space a 1/3 full. This will allow for additional oil to be available to the bearings during high-heat conditions. I have been running this setup for four years using Pennzoil 707L Red Grease with good results.

Most late-model cars now use integrated hub units where the bearings are integral to the hub. These permanently sealed units are 1/3 - 1/2 full of grease.

Actually, reading your thread is what prompted my question.   I was in a middle ground before.  I always put "some" grease in the hub, just not full.  Guess I'll keep doing what has worked for me for 50 years.

[birdsandbees]

I went out and pulled my hubs after I typed that and you know what, filled to the cups is only about 1/3rd full !

BTW... boat trailer hubs with bearing buddies are completely filled and under minor pressure. The pressure keeps any water from being able to flow in. They work just fine packed 100% full.