Question about rotor replacement

[zoomblur]

I am on my second Discovery II (2001 SE), and still a novice at DIY repairs. My brakes are squealing a bit, and I guess it's time to replace something. I have replaced brake pads before, so I feel like I have a handle on this part. My question is...and I know what the "right" answer will be...but if I can get away with just replacing pads that would be A-OK with me. However, I want to be safe and need to know how to determine if my rotors are in good enough condition to hold up, and for how long? I have heard some say that if I replace pads with "softer" ones that the rotors will last longer, but the pads will wear faster. Makes sense, but I still want to be safe. If this is a viable scenario, which pads are the softer ones? Then again, could I go ahead and use higher end pads? Also, what is "scooping" and how do I know if my rotors are doing this? Finally, if I just replace pads, is there anything I should do to the rotors?

I learn quickly, and am very technically-minded, but I need detailed answers to be confident I'm not making costly mistakes. Thanks for the help.

[O.B.]

Any time you replace the pads, you should have the rotors turned (resurfaced) at a machine shop. This ensures the rotor surface is flat and true, thereby maximizing the contact area of your rotors and pads. All rotors have a minimum thickness that they can be turned to, if that thickness is out of limits, you'll need two new rotors for whatever axle your doing (keep the rotors matched on each axle). Diso rotors do not seem to hold up that long before they wear out of limits, so replacing them is usually routine versus resurfacing them. Popular Rover parts retailers offer brake kits that have new pads and rotors, so that doing brakes is a simple remove and replace affair, with no trips to the machine shop.
For a quicky brake pad replacement (low milage rotors), I'd recommend putting brake pad conditioner on the pads before assembly. Applied it to the pads and let it soak in. It'll help break in your pads (they'll form on the rotors) and prevent squealing and chattering.

[Disco Mike]

Just want to toss my 2 cents worth into this brake issue. Rover rotors can not be resurfaced for 2 reasons. The first is the alloy used is too soft and the second is that it takes at least 2 cuts, while turning a rotor, one to remove all the warpage, the second is a finishing cut. If you cut a Rover rotor there will not be enough material to stay in specs and they will warp causing a brake shudder when stoping.
If your rotors are within specs. and you are wanting to clean them up to stop brake squeal, using a high speed disc sander to cut the glaze will give a new set of brake pads a good surface to seat into. So, take your rotors to a shop and have them measured and then decide what to do.
As for pads, check with Atlantic British or one of the other suppliers and buy a good set of pads that do not leave alot of brake dust on the rotors. Brake dust is one of the biggest causes of brake squeaking. Also buy some brake sound deadening material, from your local auto parts store, and apply lots to the back of the brake pads prior to installing. This step will help with brake noise also.
When you are all done, do a full brake flush to get rid of your old fluid and give you a firmer brake pedal.
Brakes on a DII are very easy to do, so go for it.
Mike

[zoomblur]

Thanks for the help. I read a ton of threads before posting my own, and saw that we can't resurface Disco rotors. But I got a little confused on some of the posts which sounded like I could just pop out my old pads and stick in new ones. I've fallen pray as well to the dealership's relentless pursuit of the complete brake job. I know the complete replacement is a job I can do on my own, but at the same time, I don't think we should have to replace parts before they are completely worn. D-Mike, you said "if your rotors are within spec" they could be sanded down to de-glaze them, but what is within spec? This is really the question that I need answered. Should the rotors be at least the thickness of a --fill in the blank-- to be able to make it through a second set of pads?

I also see a lot of posts about DAP rotors combined with EBC kevlar pads. If I buy these, will the rotors outlast multiple rounds of pads, or do rotors universally need to be replaced each time the pads are gone?

Thanks again.

[Disco Mike]

On the hub of the rotor will be stamped a spec thickness. Most shops will have a guage so they can measure them.
How many miles are on your truck and are they originial rotors?
One thing you need to understand about rotors, especially Rover rotors. Our rotors are way to small for the weight of the truck and Rover in their infinate wisdom made a softer rotor that will stop better, but wear out faster. So no mater what pad you select, the rotors are going to go south on you sooner then you want. One old rull of thumb around rotors has always been that if your brake rotors are not warped and don't shudder, don't replace them, but with Rovers that get so hot when stopping this doesn't always hold true. Most likely you will need rotors if you have over 40,000 miles.
I use the Kevlar pads you mentioned and really like them, onr differance though, I have DBA rotors that are slotted and drilled for better stopping power. By the way, that combination of pads and rotors I am using have gone nearly 45.000 miles and the pads are with 5000 miles of replacement, the rotors are still good.
Mike

[zoomblur]

Once again, D-Mike, I appreciate the help. I will order one of these sets and get working. Can you think of anything that a newbie like me may not know? I don't expect to get instructions with my brake set, although I could be wrong. From what I've gathered on these groups, and photos posted on John Lee's page for pad replacement, I should be able to handle it. But can you think of that one thing that we both know is going to stump me right in the middle of my first wheel? This is usually what keeps me from the DIY jobs, the uncertainty of knowing all steps. Experienced guys tend to skip steps in their descriptions. Hopefully you're reading my humor! Any special tools or tricks? Thanks again.

[Muddy Oval]

Don't run the Kevlar pads on stock rotors- only with DBA's or some other high end aftermarket rotor. Mike is dead-on correct about everything he stated above. On my own, I usually replace the pads before any scoring takes place. I'd rather change them on MY time- on a nice day when I have some spare time- than when they go bad which will score the rotors and probably be cold and rainy. I go by the old two sets of pads, then change rotors- rinse, repeat. I always check for cracks etc when installing new pads on old rotors.

[O.B.]

Originally Posted by zoomblur

Can you think of anything that a newbie like me may not know? I don't expect to get instructions with my brake set, although I could be wrong.

The only tricky thing I can think of is compressing the calipers to fit the new pads and rotors; what has worked for me is compressing them with the old pads still in the caliper housing, and using a brake compression tool or adaquate C-clamp to push the piston in.
Compress them until they're all the way in. Make sure the caliper pistons stays centered and straight during compression so you don't scratch the sleeve or rip a seal. The rest is easy

[Disco Mike]

Originally Posted by O.B.

The only tricky thing I can think of is compressing the calipers to fit the new pads and rotors; what has worked for me is compressing them with the old pads still in the caliper housing, and using a brake compression tool or adaquate C-clamp to push the piston in.
Compress them until they're all the way in. Make sure the caliper pistons stays centered and straight during compression so you don't scratch the sleeve or rip a seal. The rest is easy

Also check your brake fluid levek before you start changing out pads, if it is too high it will over flow, all over the maste cylinder making a masty mess, while you are compressing the pistons. Then of course do a good fluid change, I usually do a gravity bleed since it only takes one person to do it.
Have fun,
Mike