Brake Calipers

289, FIA & Daytona topics
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clive
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Re: Brake Calipers

Post by clive »

Hi David,
Sorry to hear about your ongoing problem. Have you looked at Willwood calipers? http://www.wilwood.com/index.aspx
Cheers, Clive.

(If I'm not here I'm in my workshop or on the golf course!)
Colin Newbold
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Re: Brake Calipers

Post by Colin Newbold »

Hi David

What a nightmare :cry:

I'm not sure what your rear suspension set up is but I'm assuming MGB live axle with some sort of disc brake conversion - yes?

Knowing how much your car means to you and the money you've invested - albeit over a long period of time - I would recommend you picking up the phone to HiSpec in Dartford and talking to the boss there about your problem. It may cost a bit, but I'm sure he would be able to engineer for you a bespoke permanent solution - disc, disc bell and caliper (actually the only thing that would need to be engineered probably is the disc bell as the disc and caliper would be off the shelf. They specialise in low volume and one-offs. You would have to take a day off work I suspect to take the car down to show him, but that's my advice, for what its worth. 8)

Find them here:
http://www.hispecbrake.co.uk
01322 286 850

Good luck!

Colin
"How you see yourself is all very well, but it's how others see you that will determine the results you get as a leader!"
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RUT220G
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Re: Brake Calipers

Post by RUT220G »

Hi David,

I have the same setup as you on the rear axle, albeit I have vented discs and I think you have single discs. I have had no problems with the Sierra calipers on my rear discs, although I do know they were brand new when fitted and not reconditioned. There must have been thousands of cars using Sierra calipers over the years and not had problems with them. I don't think they are too expensive so I would just source and fit a new set.
Allan Tunstall
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Roger King
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Re: Brake Calipers

Post by Roger King »

RUT220G wrote:Hi David,

I have the same setup as you on the rear axle, albeit I have vented discs and I think you have single discs. I have had no problems with the Sierra calipers on my rear discs, although I do know they were brand new when fitted and not reconditioned. There must have been thousands of cars using Sierra calipers over the years and not had problems with them. I don't think they are too expensive so I would just source and fit a new set.
1.3 million Sierras sold in Britain alone, so I'd say you have a good point there.
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Migge
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Re: Brake Calipers

Post by Migge »

Special customized BRA289
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David Large
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Re: Brake Calipers

Post by David Large »

RUT220G wrote:Hi David,

I have the same setup as you on the rear axle, albeit I have vented discs and I think you have single discs. I have had no problems with the Sierra calipers on my rear discs, although I do know they were brand new when fitted and not reconditioned. There must have been thousands of cars using Sierra calipers over the years and not had problems with them. I don't think they are too expensive so I would just source and fit a new set.
Alan,

The same thought crossed my mind a few weeks ago, and I now have a differently supplied calliper on the offside rear,. this whole thing has shaken my confidence a bit, the only thing that is strange is that there has not been a failure when braking, they leak when it is parked!

David
David Large
Bald surfer with a BRA 289, Porsche 968 Coupe and a Radical PR6!
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RUT220G
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Re: Brake Calipers

Post by RUT220G »

Hi David,

Reading through this thread again makes me think there might be something wrong with the way your handbrake cable is attached to the calipers. Difficult to say exactly what but as a longshot a strain the wrong way on the handbrake lever might cause a seal failure there.

Is it possible to post a picture?
Allan Tunstall
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David Large
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Re: Brake Calipers

Post by David Large »

Yes,

I had thought about this but I do not know.

I will post a picture, but my thoughts on this are that the seal on the handbrake spindle is more of a dust seal and that there is a main hydraulic seal within the calliper on the piston?

I don't know if this is right or wrong.


When I have sent callipers back to Bigg Red all he says is that they do not leak, so maybe you are right.

I would add however that 2 of the 3 failures have occured when the car is parked with no handbrake applied and the third occurred when the handbrake was applied (in Scotland).

David
David Large
Bald surfer with a BRA 289, Porsche 968 Coupe and a Radical PR6!
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clive
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Re: Brake Calipers

Post by clive »

Although it is unusual for a leak to occur when there is no pressure in the system, it is not impossible. If a seal has a kink or slight tear when it is under pressure the force of fluid on the leak could actually seal it, whereas if it is not under pressure the seal may weep. It appears from what you say Bigg Red are only testing the calipers under pressure. Perhaps you should speak to them and ask if they can test them when they are not under pressure.
Just another thought as I am writing this. Are you sure that you are using the correct thread for the pipes and bleed valves? It could be that you are using imperial unions when you should be using metric or vice versa. There is very little difference, but it might be sufficient to cause the leak when no pressure is in the system.
Cheers, Clive.

(If I'm not here I'm in my workshop or on the golf course!)
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David Large
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Re: Brake Calipers

Post by David Large »

Good thought but the fluid definitely comes down the handbrake spindle.
I need to research the angle of pull on the handbrake. I will photograph the set up on Saturday morning.

David
David Large
Bald surfer with a BRA 289, Porsche 968 Coupe and a Radical PR6!
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