Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: nitehawk on October 09, 2018, 10:27:55 am

Title: "Skin" Cut my Takeoff Rotor?
Post by: nitehawk on October 09, 2018, 10:27:55 am
The right rear rotor is grooved a bit, but not excessively, on the outside facing side.
New rotor is not cheap, so can I have the rotor skin cut to clean up?
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: wolfe10 on October 09, 2018, 10:56:44 am
Maybe.  You will need the minimum thickness dimension which is often stamped on the rotor itself.

If it cleans up within that spec, no problem.
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: stump on October 09, 2018, 10:59:13 am
I would cut it. There is a minimum measurement I'm sure. It's not like you drive it 2500 miles a week.
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: craneman on October 09, 2018, 11:09:10 am
Others will disagree, but I leave the grooves in on cars, trucks and motorhomes. Warping is the bigger problem. Having grooves only increases the braking area after the shoes or pads wear in. Any time you make the rotor or brake drum thinner they will heat up more. Liability issues and a little more profit are why shops always recommend turning them.
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: nitehawk on October 09, 2018, 11:12:25 am
I have already replaced the rotor--in June. This rotor I planned on keeping for a spare for the next owner. I figure the original setup lasted for 84,000 miles and I don't think we will be able to put that many miles on the replacement parts, due to our ages and medical issues.
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: craneman on October 09, 2018, 11:16:59 am
I have already replaced the rotor--in June. This rotor I planned on keeping for a spare for the next owner. I figure the original setup lasted for 84,000 miles and I don't think we will be able to put that many miles on the replacement parts, due to our ages and medical issues.
I have over 100,000 mi. and the rotors and pads hardly show any wear. You must have had an issue to lose them at 84,000 mi.
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: nitehawk on October 09, 2018, 11:32:41 am
Previous three owners must have traveled thru the mountains a lot. Not us. Outside disc brake pad let go at some time in the past. Don't know when, as we always very tenderly applied the brakes. Usually coasted when seeing a stop coming up ahead.
As you know, diesel pushers use the rear brakes for most of the stopping, due to the engine being the weight factor.
I replaced the front brake pads (I did passenger front before my cancer surgery and a shop did the driver's side) and found the old ones to be almost the same thickness as the new pads. But, I am a nut about some things and braking is nothing to scrimp on. So now we have new brake pads all around, along with the new rotor on the passenger rear.
I even put new pads on our Saturn Vue. The rear drum brake shoes looked like new so they were left alone.

Mental comfort level?? Way up there now!!
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: craneman on October 09, 2018, 11:37:32 am
Previous three owners must have traveled thru the mountains a lot. Not us. Outside disc brake pad let go at some time in the past. Don't know when, as we always very tenderly applied the brakes. Usually coasted when seeing a stop coming up ahead.
As you know, diesel pushers use the rear brakes for most of the stopping, due to the engine being the weight factor.
I replaced the front brake pads (I did passenger front before my cancer surgery and a shop did the driver's side) and found the old ones to be almost the same thickness as the new pads. But, I am a nut about some things and braking is nothing to scrimp on. So now we have new brake pads all around, along with the new rotor on the passenger rear.
I even put new pads on our Saturn Vue. The rear drum brake shoes looked like new so they were left alone.

Mental comfort level?? Way up there now!!
Nighthawk, I forgot you don't have much engine braking on your model.
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: Pierce & Gaylie Stewart on October 09, 2018, 12:05:43 pm
With over 100K on our coach, the rotors don't show any wear. Check your pins for free movement if one set or one side is showing much wear or discolored.

While grooves on the surface may give the rotor more surface area, it will take time for the pads to wear enough to make them contour to the rotor surface. If one side of the coach/axle has more wear/grooves than the other, uneven braking could occur until the pads conform.

For those thinking about increasing the rear can size to allow better braking effectiveness, this may cause rear wheel lockup on roads with slick conditions like rain or snow.

Pierce
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: craneman on October 09, 2018, 12:19:33 pm
With over 100K on our coach, the rotors don't show any wear. Check your pins for free movement if one set or one side is showing much wear or discolored.

While grooves on the surface may give the rotor more surface area, it will take time for the pads to wear enough to make them contour to the rotor surface. If one side of the coach/axle has more wear/grooves than the other, uneven braking could occur until the pads conform.

For those thinking about increasing the rear can size to allow better braking effectiveness, this may cause rear wheel lockup on roads with slick conditions like rain or snow.

Pierce
Pierce here is the condition of the brakes.
 helper springs (http://www.foreforums.com/index.php?topic=31008.msg271318#msg271318)
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: Pierce & Gaylie Stewart on October 09, 2018, 12:37:38 pm
Your pads look like new! Pins cleaned up nicely. I've got to do the same as they probably need it too. I'm on the fence about the helper springs. Your opinion?

Pierce
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: craneman on October 09, 2018, 12:52:15 pm
I installed them figuring Meritor would not make and suggest them if they didn't work
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: RvTrvlr on October 09, 2018, 12:59:38 pm
I put new pads on my deeply grooved almost brand new rotor from the Previous owner. It went metal to metal pretty bad and wore four grooves pretty deep. Used a scotch brite polishing wheel on a drill to polish the roughness out and threw new pads on. Checked them a few thousand miles later and they had conformed to the grooves quickly and perform well. Now over 30,000 miles later they still look great. Not ideal, but I wanna travel more and spend less on repairs and this was an easy decision to make that has thus far performed fine.
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: Keith and Joyce on October 09, 2018, 01:27:45 pm
So long as the grooves are shallow and don't affect the strength of the rotor don't worry about it.  But find out why they are grooved.  For example something embedded in the pad.

Keith
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: nitehawk on October 09, 2018, 07:43:15 pm
Here we go again. Posts have nothing to do with my question re resurfacing a rotor.
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: Carol & Scott on October 10, 2018, 12:10:24 am
Helper Springs - Have have had sets on both our 36 and 42.  If your are doing the pins that would be a good time to add. not expensive.  Meritor produced them for a reason.  I think they do add some back pressure to reduce brake drag, premature pad/ disk wear.
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: bbeane on October 10, 2018, 12:23:54 am
Here we go again. Posts have nothing to do with my question re resurfacing a rotor.
Sounds to me like folks where answering your questions. As always DWMYFG.
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: Old phart phred on October 10, 2018, 01:18:04 am
This a grey area, a lot of shops won't resurface rotors due to liability, if they do they Might require to Be matched and new pads.
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: nitehawk on October 10, 2018, 08:22:25 am
Don't have Meritor Brake system or air brakes.Remember, this is a 1989 Oshkosh truck chassis with leaf springs, regular disk brakes, DD 8.2 Turbo-charged 200 HP V8 and a four speed Allison tranny. No fancy engine assist braking system.
Drive train and braking are similar to a garbage truck or a 1989 pickup.
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: Protech Racing on October 10, 2018, 08:38:35 am
 I run them with some grooves.  I  resist turning rotors at my shop if they dont shake . The runout is always higher  post machining .  And I am pretty anal about my machines.   

 Or you can Turn it , Measure it . Make a decision.    Keep an eye on the pads for a few miles as the COF changes with fresh steel presented.
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: Dave Larsen on October 10, 2018, 08:47:05 am
Just let the next owner make the decision.
Title: Re: "Skin" Cut my Takeoff Rotor?
Post by: nitehawk on October 10, 2018, 09:33:32 am
New rotor on the passenger side and "old" rotor on the driver's side. I "tested" brakes after completion of brake job.
I stood on the brakes to see how the coach stopped under hard braking application. Straight as an arrow. No pulling to either side. (testing was initiated at 45 MPH)
Really happy with complete renovation of braking system. ^.^d