How Worn Are My Rotors?
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12-15-2016, 07:48 AM
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12-15-2016, 07:55 AM
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orangeblossom (12-15-2016)
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12-15-2016, 08:11 AM
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orangeblossom (12-15-2016)
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12-15-2016, 08:14 AM
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orangeblossom (12-15-2016)
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12-15-2016, 09:45 AM
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Just my views, not pass MOT oriented. It isn't normal wear that reduces thickness,
but turning to clean up scoring.
If in turned and unscored, the average rotor is just fine.
I'm not a fan for turning the rotors just to get a pristine surface. But, deep scoring, to my way of thinking means new rotors.
One of my old critters ate a rotor. Really deep scoring. As it was a 4x4, the swap not really easy. I nursed it through a winter by a pad swap or two.
But, complex as it was, fun and games when compared to a Jaguar IRS rotor swap!!!
In the spring, I did the whole thing. Rotors, bearings, seals and pads. Sold, not that
much later. The "happy wife" thing...
Carl
but turning to clean up scoring.
If in turned and unscored, the average rotor is just fine.
I'm not a fan for turning the rotors just to get a pristine surface. But, deep scoring, to my way of thinking means new rotors.
One of my old critters ate a rotor. Really deep scoring. As it was a 4x4, the swap not really easy. I nursed it through a winter by a pad swap or two.
But, complex as it was, fun and games when compared to a Jaguar IRS rotor swap!!!
In the spring, I did the whole thing. Rotors, bearings, seals and pads. Sold, not that
much later. The "happy wife" thing...
Carl
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orangeblossom (12-15-2016)
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12-15-2016, 10:05 AM
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orangeblossom (12-15-2016)
#7
12-15-2016, 10:34 AM
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#8
12-15-2016, 10:41 AM
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I have never known an mot tester check the thickness of discs, there either failed on scoring or because there distorted on the brake tester, don't let them check the rears individually as it could damage the LSD. but they should all be aware of LSD testing directive, but not what cars have them particularly.
Last edited by rgp; 12-15-2016 at 11:02 AM.
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orangeblossom (12-15-2016)
#9
12-15-2016, 11:01 AM
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12-15-2016, 11:03 AM
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12-15-2016, 12:39 PM
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orangeblossom (12-15-2016)
#12
12-15-2016, 12:54 PM
Hi rgp
No, I've never heard of a Tester doing that either, they don't even give them a look at the place that I go.
But they Do Test the Rear Axle on The Rolling Road, even though I've always made a point of telling them that the Car has a Limited Slip Diff.
Where they say the Rolling Road, is able to compensate for that without causing a problem.
Unlike another Garage that I used to take her to, that point blank refused to Test the Rear Axle on their Rolling Road, just in case it happened to do any damage.
I can remember that MOT Test just as if it was yesterday, I had the roof down at the time as the Sun shot out of an Azure Blue Sky, peppered with little White Fluffy Clouds on one of the hottest days I can remember.
Did I have 'The Shades' on course I did, together with 10 gallons of Factor 30 and felt my little heart swelling with pride, secure in the knowledge that at last I'd found a Caring garage, who seemed happy enough to gloss over the fact that the Windscreen Washers were not working.
As over the years I have managed to develop a line of Patter, that seemed to have convinced them that I never went out in the rain, I mean why would you.
No doubt coupled to the fact that he could see that I was not a 'Punter' who unlike his normal Clientèle knew a fair bit about Cars, especially this one.
Or if not that then maybe it was down to the GF who was wearing Shorts so Short, that they could make a Bishop kick a hole right through a Stained Glass Window!
And so instead of the Rolling Road, they were going to Test the Rear Brakes with a thing called a 'Tapley Meter'
How it could tell the difference between the Front Brakes and The Rear Brakes, still remains a mystery to me, as for those who've never seen one its a Very Heavy Box with a Barrel Gauge on Top, which instantly had me Screaming, 'Don't put that on my Ski Slope!' (I almost wanted to Cry)
But that came later! As he then suggested I held the Box, while he drove my Car and as this was the only thing that was left to pass the Test, I took leave of my Senses and reluctantly agreed.
Sitting in the Passenger Seat felt even worse than going to the Dentist, just in case I wanted to have all of my teeth out, which by way of sheer coincidence very nearly happened! I didn't even know if he'd driven an Automatic before.
But as he clicked her into drive and then hit the loud pedal, the rear tyres started screaming as we sped off down the road, while I just sat there bathed in sweat and properly petrified.
Did you ever see that Film 'Gone in 60 Seconds' as for just one horrible minute, I thought that I was in it!
As he had quite clearly never driven a V12 Car before and I had already made up my mind that if we survived then he would never get the chance to ever drive my Car again.
While he was quite clearly enjoying the ride, I just wanted to die! which reminds me to be careful what you wish for, as the second he hit the Brakes, the weight of the 'Tapley Meter' that was resting on my lap, suddenly started to pull me towards the Windscreen.
Knowing if I let it go, then it would almost certainly bury itself in the 'Dash' with shards of Walnut flying everywhere.
You didn't need a Meter, to know She passed the Test as when he put the Anchors on, which seemed to rhyme with what I remember calling him under my breath, She just stopped dead!
And though She passed with flying colours, I made up my mind that I was never going back to that Garage again and never let that 'Boy Racer' anywhere near my Car.
No, I've never heard of a Tester doing that either, they don't even give them a look at the place that I go.
But they Do Test the Rear Axle on The Rolling Road, even though I've always made a point of telling them that the Car has a Limited Slip Diff.
Where they say the Rolling Road, is able to compensate for that without causing a problem.
Unlike another Garage that I used to take her to, that point blank refused to Test the Rear Axle on their Rolling Road, just in case it happened to do any damage.
I can remember that MOT Test just as if it was yesterday, I had the roof down at the time as the Sun shot out of an Azure Blue Sky, peppered with little White Fluffy Clouds on one of the hottest days I can remember.
Did I have 'The Shades' on course I did, together with 10 gallons of Factor 30 and felt my little heart swelling with pride, secure in the knowledge that at last I'd found a Caring garage, who seemed happy enough to gloss over the fact that the Windscreen Washers were not working.
As over the years I have managed to develop a line of Patter, that seemed to have convinced them that I never went out in the rain, I mean why would you.
No doubt coupled to the fact that he could see that I was not a 'Punter' who unlike his normal Clientèle knew a fair bit about Cars, especially this one.
Or if not that then maybe it was down to the GF who was wearing Shorts so Short, that they could make a Bishop kick a hole right through a Stained Glass Window!
And so instead of the Rolling Road, they were going to Test the Rear Brakes with a thing called a 'Tapley Meter'
How it could tell the difference between the Front Brakes and The Rear Brakes, still remains a mystery to me, as for those who've never seen one its a Very Heavy Box with a Barrel Gauge on Top, which instantly had me Screaming, 'Don't put that on my Ski Slope!' (I almost wanted to Cry)
But that came later! As he then suggested I held the Box, while he drove my Car and as this was the only thing that was left to pass the Test, I took leave of my Senses and reluctantly agreed.
Sitting in the Passenger Seat felt even worse than going to the Dentist, just in case I wanted to have all of my teeth out, which by way of sheer coincidence very nearly happened! I didn't even know if he'd driven an Automatic before.
But as he clicked her into drive and then hit the loud pedal, the rear tyres started screaming as we sped off down the road, while I just sat there bathed in sweat and properly petrified.
Did you ever see that Film 'Gone in 60 Seconds' as for just one horrible minute, I thought that I was in it!
As he had quite clearly never driven a V12 Car before and I had already made up my mind that if we survived then he would never get the chance to ever drive my Car again.
While he was quite clearly enjoying the ride, I just wanted to die! which reminds me to be careful what you wish for, as the second he hit the Brakes, the weight of the 'Tapley Meter' that was resting on my lap, suddenly started to pull me towards the Windscreen.
Knowing if I let it go, then it would almost certainly bury itself in the 'Dash' with shards of Walnut flying everywhere.
You didn't need a Meter, to know She passed the Test as when he put the Anchors on, which seemed to rhyme with what I remember calling him under my breath, She just stopped dead!
And though She passed with flying colours, I made up my mind that I was never going back to that Garage again and never let that 'Boy Racer' anywhere near my Car.
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rgp (12-15-2016)
#13
12-15-2016, 01:01 PM
Cheers! I think they will look a lot better when I've cleaned up the rims with a wire brush, as there are no signs of Scoring anywhere on the discs.
#14
12-15-2016, 01:03 PM
#15
12-15-2016, 01:06 PM
Just my views, not pass MOT oriented. It isn't normal wear that reduces thickness,
but turning to clean up scoring.
If in turned and unscored, the average rotor is just fine.
I'm not a fan for turning the rotors just to get a pristine surface. But, deep scoring, to my way of thinking means new rotors.
One of my old critters ate a rotor. Really deep scoring. As it was a 4x4, the swap not really easy. I nursed it through a winter by a pad swap or two.
But, complex as it was, fun and games when compared to a Jaguar IRS rotor swap!!!
In the spring, I did the whole thing. Rotors, bearings, seals and pads. Sold, not that
much later. The "happy wife" thing...
Carl
but turning to clean up scoring.
If in turned and unscored, the average rotor is just fine.
I'm not a fan for turning the rotors just to get a pristine surface. But, deep scoring, to my way of thinking means new rotors.
One of my old critters ate a rotor. Really deep scoring. As it was a 4x4, the swap not really easy. I nursed it through a winter by a pad swap or two.
But, complex as it was, fun and games when compared to a Jaguar IRS rotor swap!!!
In the spring, I did the whole thing. Rotors, bearings, seals and pads. Sold, not that
much later. The "happy wife" thing...
Carl
If I had to drop the IRS I wouldn't even consider turning the Rotors, as after going through that pain, there's no way I would want to do that twice.
#16
12-17-2016, 08:39 AM
Veteran Member
OB.
The thickness of the discs seems fine for an MoT pass. Perhaps worth turning the axle and cleaning up the edge of the discs with a screwdriver. MoT testers will comment as advisories on thickness of pads and possibly discs if very worn.
As regards the brake test. There are some brake test rollers that can now handle mechanical LSDs. My test station installed one this year and used it for my XJS whereas before they always used the Tapley meter. Make sure you advise the test station that the car has a mechanical, not electronic, LSD. If they say that they can do it on the rollers, ask them to explain how that won't cause wind-up on the axle. It may be that they have the new roller setup.
Paul
The thickness of the discs seems fine for an MoT pass. Perhaps worth turning the axle and cleaning up the edge of the discs with a screwdriver. MoT testers will comment as advisories on thickness of pads and possibly discs if very worn.
As regards the brake test. There are some brake test rollers that can now handle mechanical LSDs. My test station installed one this year and used it for my XJS whereas before they always used the Tapley meter. Make sure you advise the test station that the car has a mechanical, not electronic, LSD. If they say that they can do it on the rollers, ask them to explain how that won't cause wind-up on the axle. It may be that they have the new roller setup.
Paul
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orangeblossom (12-17-2016)
#17
12-17-2016, 11:28 AM
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Tapley!!! I've no heard of those for decades. An instrument to measure "G" forces.
Decelerate for brake effect. Accelerate for traction/ power.
Slick.
Well, neither of my cars has LSD. Each has been on the "rolling road" more than once. SMOG tested. Merely, to analyze performance at 15 mph and again at 25 MPH.
Certain emission standards to be met at those speeds.
Seem like giant rollers to enable stationary replication of the real road. Why would that mess with LSD? I'll muse, or mebbe not.
OTH, a form of that roller system is used as a dynometer to test HP and torque at the rear wheels. The car is usually chained to prevent an unwelcome escape!!!! Hook it up, stand on it, listen to the roar and watch the needles!!! Tons of fun.
Carl
I
Decelerate for brake effect. Accelerate for traction/ power.
Slick.
Well, neither of my cars has LSD. Each has been on the "rolling road" more than once. SMOG tested. Merely, to analyze performance at 15 mph and again at 25 MPH.
Certain emission standards to be met at those speeds.
Seem like giant rollers to enable stationary replication of the real road. Why would that mess with LSD? I'll muse, or mebbe not.
OTH, a form of that roller system is used as a dynometer to test HP and torque at the rear wheels. The car is usually chained to prevent an unwelcome escape!!!! Hook it up, stand on it, listen to the roar and watch the needles!!! Tons of fun.
Carl
I
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orangeblossom (12-18-2016)
#18
12-17-2016, 11:33 AM
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#19
12-17-2016, 02:53 PM
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orangeblossom (12-17-2016)
#20
12-17-2016, 05:08 PM
OB.
The thickness of the discs seems fine for an MoT pass. Perhaps worth turning the axle and cleaning up the edge of the discs with a screwdriver. MoT testers will comment as advisories on thickness of pads and possibly discs if very worn.
As regards the brake test. There are some brake test rollers that can now handle mechanical LSDs. My test station installed one this year and used it for my XJS whereas before they always used the Tapley meter. Make sure you advise the test station that the car has a mechanical, not electronic, LSD. If they say that they can do it on the rollers, ask them to explain how that won't cause wind-up on the axle. It may be that they have the new roller setup.
Paul
The thickness of the discs seems fine for an MoT pass. Perhaps worth turning the axle and cleaning up the edge of the discs with a screwdriver. MoT testers will comment as advisories on thickness of pads and possibly discs if very worn.
As regards the brake test. There are some brake test rollers that can now handle mechanical LSDs. My test station installed one this year and used it for my XJS whereas before they always used the Tapley meter. Make sure you advise the test station that the car has a mechanical, not electronic, LSD. If they say that they can do it on the rollers, ask them to explain how that won't cause wind-up on the axle. It may be that they have the new roller setup.
Paul
I'm pretty sure my MOT Garage has the latest equipment, as everything regarding the Test is displayed on a giant sized LCD.
And I have also asked him about this before, where he has assured me that the IRS won't be damaged during the Test.
But as for the Tapley Meter Test that really freaked me out! As I had to decide on the lesser of the Two Evils.
If I drove the Car and slammed the Brakes on and the Tester let the Meter suddenly slip from his grasp and it damaged the dashboard, then no doubt they would try and pass that buck over to me.
So on the balance of probability that he wouldn't have an accident while he was driving my Car a very short distance, I thought it would be Safer if I let him drive while I was holding onto the Tapley Meter.
Which seems to show just how wrong you can be, as he certainly wasn't used to the Car or understand the power of a V12.
So seeing the opportunity to drive one, he wasn't intending to waste it by taking it easy and the road out of the Garage, was not only narrow but was also packed with Cars both sides.
Which not only meant a trip round the block but also squeezing past other Cars that were coming in from the other direction, at which point I was feeling sick and sitting there wanting to Cry.
And that was one experience that I never want to go through ever again!
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ptjs1 (12-17-2016)