Hot Spinners

PostPost by: john.p.clegg » Sat Jul 28, 2007 4:27 pm

Last week treated the +2 to new pads all round and new rear pistons.After bleeding the system and adjusting the hand brake centralising strips took her for a gentle jog to test the brakes.....all was going well but to my tuned ear ricocheting (sp) off the side walls was an intermittent gentle ticking sound (put down to stones in the tread?)
Well 12 miles later after a couple of gentle stops and one of two screeching halts returned to base and boy are those front spinners hot....
Now here's the questions
1) should the front spinners get so hot while the rears are cold?

2) what is the ratio of front to rear braking?

3)would removing the dust shields improve cooling?

I will wait till they cool down before checking the end-float of the front hubs (could that be a/the problem?)

John :wink:
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PostPost by: tower of strength » Sat Jul 28, 2007 5:48 pm

the front spinners will get hot as the heat transfer from the hub is directly to the wheel, the rears brakes are in board of the bearings and also do a lot less work. In My Humble opinion this would be normal, the ticking noise not so and warrants investigation.

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PostPost by: john.p.clegg » Sat Jul 28, 2007 5:57 pm

Stupid me! Of course there is a lot of metal between the rear discs and spinner,not so on the front...

John :wink:
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PostPost by: types26/36 » Sat Jul 28, 2007 6:22 pm

Tut Tut John, I also have these senior moments :lol:
Wouldn't know the ratio of front to rear braking as I am not aware of a porportioning valve unless a +2 has one? think it would have to be worked out with given piston size/fluid displacement and brake pad area :? :?
as regards the bearing end float causing a problem .....not unless you have tighten up the bearings with no end float and I dont think you would do that.
Also unsure if the disc's would be cooled better with no sheilds and my guess would be yes.....but its a guess :roll:
Sounds like you could have dragging brakes......servo sticking? caliper pistons sticking? jack up the car and check for wheel drag,
Brian
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PostPost by: john.p.clegg » Sat Jul 28, 2007 10:29 pm

Have axle stands on all four corners and all wheels spin freely,will check endfloat in the morning,maybe the front spinners do get that hot when bedding in new pads ....Have never felt the front spinners after a bout of braking before,maybe I should do more often....

John :wink:
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PostPost by: rgh0 » Sun Jul 29, 2007 4:28 am

After a race the front wheels on my Elan are normally to hot to touch but the rears are close to ambient temperature. So if you have been using your brakes hard having hot front spinners would not be abnormal.

There is just a lot more heat load from the front brakes and the disks are much closer to the wheels and hubs. The front disks on my Elan get to around 600 degrees C while the rear disks stay below 400 degrees C according to the temperature indicating paint I use.

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Rohan
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PostPost by: john.p.clegg » Sun Jul 29, 2007 7:30 am

And surely by now someone has found a better way of securing the castellated nuts on the front hubs,it's proving a bugger-as usual- to remove/insert the split pins?

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PostPost by: tower of strength » Sun Jul 29, 2007 10:11 am

john.p.clegg wrote:And surely by now someone has found a better way of securing the castellated nuts on the front hubs,it's proving a bugger-as usual- to remove/insert the split pins?

John :wink:


long nosed pliers, never had a problem myself

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PostPost by: john.p.clegg » Sun Jul 29, 2007 11:01 am

Mark

But the length of the split pins to go through the nuts makes it v.difficult to insert in the hub?

John :wink:
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PostPost by: elandoc » Sun Jul 29, 2007 1:03 pm

Hi John,
The F/R ratio in an S3 is 2:1. That's from measuring piston area in the standard set up. A lot of Elans go to +2 F discs and calipers which improves stopping power, but gives too much F bias IMHO. I carefully arranged a 2:1 F/R bias when I fitted the 4 pot F calipers, but forgot I had the larger F discs, so I have too much F bias as well. My next trick is to fit a tandem pedal box with balance bar but the 26R ones are made of unobtainium, so I have some head scratching to do, unless anyone out there has managed to do it? Let me know.
Cheers
Patrick
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PostPost by: Foxie » Sun Jul 29, 2007 6:32 pm

Patrick,

Do I understand correctly you have +2 discs and 4 pot calipers ?
If so, what type/make are the calipers ?

Sean
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PostPost by: tower of strength » Sun Jul 29, 2007 6:36 pm

john.p.clegg wrote:Mark

But the length of the split pins to go through the nuts makes it v.difficult to insert in the hub?

John :wink:

hold the split pin in the middle, leaning back towards you, poke the end in the hole and then push home, never had a problem myself, trouble is I'm crap at getting the correct torque on the bearing nut, always either too loose or tight and end up doing it 3 or 4 times, so I've had lots of practice!!LOL, could it be you are using too long a split pin?

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PostPost by: elandoc » Mon Jul 30, 2007 11:57 am

Sean,
Yes, +2 discs with Wilwood Billet Dynalites - 4 pot on the front... 1300g, I think, and the 2 pot on the rear...730g or thereabouts. I researched long and hard and they were the lightest in the world and quite cheap, too. But that was a few years ago. Custom caliper mounts machined out of 7075T6 alloy. I needed a handbrake to comply with the rules, so I added downhill mountain bike calipers at 120g each - I'll try to remember to post a photo sometime.
Cheers
Patrick
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PostPost by: GrUmPyBoDgEr » Mon Jul 30, 2007 1:01 pm

I agree with John about the difficulty with the split pins, I expect that Mark's right hand has two fingers that look like thin nosed pliers :lol:
Those pliers are a must though. In my struggles to do the job I cut the length of the split pin to the minimum necessary & then form a bend in it that will still pass through the hole in the stub axle. Pulling the old split pin out actually produces the required amount of twist, which is why I have often re-used, in contradiction to the Bible. However to reduce the fatigue in the split pin I only open out the ends minimally so that the pin does it's job & no more.
Nevertheless it's like working in a black hole and a real pain, one of the jobs that annoys me also.
Aaah another fiddly job to look forwad to when I get around to fitting those shiny new Wilwood 4 pots :roll:
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John
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PostPost by: elansprint71 » Mon Jul 30, 2007 2:54 pm

John,
I always bend the split pins into a slight curve before trying to insert them.

The ticking? That will be your ABS :twisted:

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Pete.
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