Brake rotor scored

Topic: Brake rotor scored (Read 1964 times) previous topic - next topic

Brake rotor scored

September 19, 2019, 12:36:14 pm

I took off a wheel (rr outside) to take in for a flat repair and on inspection saw that the rotor had been scored, likely due to the brake dragging, since it was on the outside (inboard pad usually wears first). I usually check my brakes before each trip, so this had to be a recent event. If this happened on a car, I would take the rotor off and have the rotor turned. Is it possible to do so with these rotors? Can we reasonably expect to replace the rotor (if it comes to that) and pads ourselves?
Since I'm on the last week of completing my RV barn, it may be a couple of weeks until I get to it, but I can do research in the meantime. If I were to do the replacements, I would take it to a certified brake repair shop to have them make the adjustments.
It is REALLY nice to have a concrete floor with a lot of room (20' wide) to work now.

Re: Brake rotor scored

Reply #1 – September 19, 2019, 12:42:04 pm

May want to consider doing the other side so both sides will be the same.

Re: Brake rotor scored

Reply #2 – September 19, 2019, 12:52:10 pm

Quote from: John44 – September 19, 2019, 12:42:04 pm

May want to consider doing the other side so both sides will be the same.

Of course.

Re: Brake rotor scored

Reply #3 – September 19, 2019, 01:06:04 pm

I doubt you will find anyone to turn the rotors. If you have the ability to r&r wheels you can certainly do the rotors pads and seals. How bad is the rotor scored? I wouldn't replace it for a small score mark. You can go to beamalarm.com and download the Meritor brake service manual MM4 it will tell you everything you need to know about the brakes.

Re: Brake rotor scored

Reply #4 – September 19, 2019, 01:06:35 pm

The rotors ability to absorb heat is reduced by thinning the rotors. If memory serves me they are around $150 each. New rotors for safety? New pads to match. Check pins? Probably pitted?

Re: Brake rotor scored

Reply #5 – September 19, 2019, 01:25:56 pm

Unless the scoring is bad you don't have to worry about it. Scoring that does not affect the integrety of the rotor is OK.

Keith

Re: Brake rotor scored

Reply #6 – September 19, 2019, 01:34:04 pm

I watched while my rotors were replaced on the rear wheels. While anyone with the ability to remove the wheels, can probably remove and replace the rotors. They are held on to the hub by several (maybe 10 or so) nuts on bolts. I don't know the term, but the nuts are a tight fit self locking type. Very difficult to remove especially when rust is involved. You can only get to them with a box wrench. Think box wrench and hammer. A rust buster will help. Let us know how it goes.

Re: Brake rotor scored

Reply #7 – September 19, 2019, 01:46:48 pm

Any machine shop can turn them.. also Charleston auto/Carquest/ Advanced auto can turn them (not sure on your size)..Or they used to

Re: Brake rotor scored

Reply #8 – September 19, 2019, 02:07:01 pm

If rotors are scored they actually have more surface area than a new one. Turning a rotor should be saved for warped rotors if you are not going to replace them. The main reason a shop will turn or replace a rotor is so the customer doesn't have to wait for the grooves to wear into the pad to have 100% contact. I never have turned a grooved rotor on my vehicles. If a rotor has lost thickness from grinding on a worn out pad then it should be replaced. This is my experience of repair work but do what makes you feel safe.

Re: Brake rotor scored

Reply #9 – September 19, 2019, 05:52:54 pm

I usually replace pads on my cars for several reasons, one being that shops insist on turning rotors regardless of condition. An inexperienced guy can take too much off a rotor, when you want to keep it to a minimum. A thin rotor will over heat and will warp, giving the vibration we have all felt at one time or other. I would replace a warped rotor. As for scoring, I was "given to understand" that a scored rotor will prematurely wear a brake pad, but don't know that for a fact.

Re: Brake rotor scored

Reply #10 – September 19, 2019, 05:58:32 pm

I had the flat repaired for $37 and asked about a brake job at Pete's. They gave me an estimate of $110 per wheel (based on usual hour to do it) coming out to $500-$600 for the back axle. I ordered the pads from Find It Parts for $249 (free shipping), which is quite a bit less than other sources. This is for two wheels, they are new and OEM. I may have Pete's do it if I can get the rotor turned (their machine is "worn out" and ineffective).

Re: Brake rotor scored

Reply #11 – September 19, 2019, 06:06:32 pm

A grooved rotor will not have 100% contact with the pad until the the pad wears into the grooves. Not very noticeable and not a safety issue. Because the grooves are circular they don't wear the pad out any sooner. I have seen grooves made by the rivets on riveted pads fairly deep on equipment I have worked on and still no problem with using the grooved rotors or drums, when drum brakes are involved. However if it bothers you just replace don't turn.

Re: Brake rotor scored

Reply #12 – September 19, 2019, 06:38:01 pm

If a picture is worth a thousand words, a video must be worth a million. All rotors have a replacement thickness spec. Look it up, especially if you are thinking about having it turned and watch the machine shop. I'm with Craneman. Check the thickness and then turn only if it's really bad. Do a search on YouTube with Meritor and pads as the key words.

Pierce

YouTube video at:
https://www.youtube.com/watch?v=bP_I2lX99jI&t=14s

Re: Brake rotor scored

Reply #13 – September 19, 2019, 06:43:47 pm

If you come down a steep grade and heat the brakes, don't set the parking brake until the rotors have had time to cool a bit as the cooling will not be even and could warp the rotors a little. Anyone watching NASCAR races can see the rotors glowing.

After a race was over, I would take a couple of laps to cool the drums (yes drums). If I stopped, the wheel cylinders would catch on fire.

P

Re: Brake rotor scored

Reply #14 – September 20, 2019, 12:14:35 am

Quote from: Pierce & Gaylie Stewart – September 19, 2019, 06:38:01 pm

If a picture is worth a thousand words, a video must be worth a million. All rotors have a replacement thickness spec. Look it up, especially if you are thinking about having it turned and watch the machine shop. I'm with Craneman. Check the thickness and then turn only if it's really bad. Do a search on YouTube with Meritor and pads as the key words.

Pierce

YouTube video at:
https://www.youtube.com/watch?v=bP_I2lX99jI&t=14s

I saw a video identical to this one, but not as entertaining. This looked pretty easy and was done on the front brakes - is it the same procedure for the rear?

Re: Brake rotor scored

Reply #15 – September 20, 2019, 01:31:50 am

They won't have a rotor for the coach but next time your need brakes on a vehicle,check out www.r1concepts.com,we have the
drilled and slotted on 2 vehicles with ceramic pads,will outlast me and stop quicker,and no dust.My opionion would be if you can
get the rotors for $150,get new ones,you have to take them off to turn anyway.

Re: Brake rotor scored

Reply #16 – September 20, 2019, 03:10:32 am

One of the rear pads became stuck and wore into the rotors before I purchased my RV. I installed a new pad (just the inner) and it quickly machined itsself to the slight wavyness worn into the rotor and has worked fine ever since. 40,000 miles on it and the pad shows no abnormal wear. In fact the rotor is now worn super smooth and just oike the others, but with slight hills and valleys. It was meant to be a quick repair to get me home after purchase but I check it often and its working just fine. I did clean up the pins and wire brushed the caliper frame where the pads touch to allow them to move freely, and this seems to have done the trick.

Re: Brake rotor scored

Reply #17 – September 20, 2019, 10:04:12 am

Good article on organic vs metallic vs ceramic pads. Decide which you want to use. https://www.autoanything.com/resources/what-are-the-best-brake-pads-ceramic-or-semi-metallic/

Pierce

Re: Brake rotor scored

Reply #18 – September 20, 2019, 10:58:40 am

Quote from: Sven and Kristi – September 20, 2019, 12:14:35 am

I saw a video identical to this one, but not as entertaining. This looked pretty easy and was done on the front brakes - is it the same procedure for the rear?

The brakes in the video are much easier to change pads on than our coaches. On ours you have to remove a slide pin and rotate the caliper up to get the pads out.

Re: Brake rotor scored

Reply #19 – October 14, 2019, 11:48:58 pm

After replacing the tires last month I was told the rear pads and the rotors needed replacing. Slack pins were also in bad shape. The wear was probably due to the rotors sticking from lack of maintenance on the slide pins or the the wrong grease used. Coach has 91000 miles.

Took the coach to Gulf Truck Parts and Repair in Saucier, Ms to get the work done. They do all kinds of chassis repair work on commercial trucks and buses and can handle big rvs also. They did all the labor and let me supply all the parts. Find it Parts had everything with free shipping except for the meritor grease which I already had.

Total Parts came to $874 which included one rotor ($271), one shoe and lining replacement kit (4 pads $286), two slide pin kits ($215) and two helper spring kits ($29).

Shop time came to $708 which was 6 hours for R&R the right rear rotor, brake pads slide pins, and helper springs. They also lubed the chassis front to back, U-joint, and slack adjusters. I had them purge the old grease from the calipers and replace it with the Meritor clay based grease. They replaced the wheel seal with a Stemco and also checked the rear end oil level.

They young guys at the shop were very courteous and easy to work with. They were fair and honest about the cost of the work and saved me $$ from having to replace the driver side rear rotor. Front brakes were just fine.

Cody who was born in 1996 was eager to learn about Meritor disk brakes on my 1993 U-300! I now have have full braking capacity along with the two stage jake and can really feel the difference.

Jerry

Re: Brake rotor scored

Reply #20 – October 15, 2019, 07:30:27 am

That photo of the old pads is the worst I remember seeing on this Forum! I don't doubt you are feeling much better braking action.

Re: Brake rotor scored

Reply #21 – October 15, 2019, 08:21:38 am

I had one that looked like that. 😬

Re: Brake rotor scored

Reply #22 – October 15, 2019, 09:43:49 am

This morning a fire department mechanic will be helping me with the brakes. Hopefully, it will be a matter of changing out the pads and replacing the grease. Fire engines go through a lot of brake pads and I will be relying on his experience. He said we could scuff the rotors if the damage is minor. I'm glad to have someone do the work in my garage so I won't have to move the rig as it is.
https://www.youtube.com/watch?v=UNdJOAb6O1Q

Re: Brake rotor scored

Reply #23 – October 15, 2019, 10:37:45 am

Jerry,

I know this is late as the brakes are back together but may help others.
With that amount of work you need to check the guide pin bushings for correct diameter and roundness. If either are out of spec. they need to be replaced and reamed to proper dia.

Mike

Re: Brake rotor scored

Reply #24 – October 15, 2019, 12:09:00 pm

Quote from: Chuck & Jeannie – October 15, 2019, 07:30:27 am

That photo of the old pads is the worst I remember seeing on this Forum! I don't doubt you are feeling much better braking action.

Chuck,
You got that right!

When coming to a stop at a red light if I had the driver side window open I could hear a grinding and scraping noise.

Amazing braking power for these coaches combined with a Jake or a retarder. Smooth steady braking with a minimal amount of pedal.

Now I see why the older fire trucks use them. Understanding Fire Apparatus Braking Efficiency - Fire Apparatus

Respect for our heroes in the fire departments who do a dangerous job every day.

Jerry

https://www.youtube.com/watch?v=emEgmW2vgVI

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