Tornado brake problem

[Trevor Skedge]

Having got the MOT on the Tornado on Saturday, I thought I would take it for a short drive. After a few miles I approached a roundabout and the brakes worked ok but once I released the pedal (still moving) the brakes continued to grab and within 20 feet the car ground to a halt. On inspection I found the fronts were completely locked on and further investigation revealed the problem was the brake servo not letting go. Once I prised out the one way valve the brakes released and all was fine. No air could pass either way through the valve until I blew hard from the back of the valve and it then released. Installed the valve back in the servo and drove the car home with no problem. Not sure if the problem actually was caused by the valve or the valve locked because of a problem with the servo. The car had been stood for 2 years before I bought it and has a separate remote brake servo for the front and rear brakes.
Any pointers would be welcome.

Trevor.

 

[Andy Sheldon]

Trevor

Sounds like you need new servos.

Thanks

Andy

 

[Trevor Skedge]

Andy,

Thanks, I have a feeling the 2 years standing on a drive has taken its toll on these.

Trevor.

 

[Tony Hunt]

Trevor,
This is a common problem with these servos. The little shuttle valve gets rusted into its bore and either catches, causing the brakes to release reluctantly, or jams up completely.
You can effect a temporary cure by polishing the bore, but the problem will recur.
The solution is either new servos, with the distinct possibilty that they will go the same way, or ditch the servos completely and fit multi-pot high performance front brakes - Wilwood, HiSpec, AP. The multiple pots replicate the servo effect.
An added advantage is that you save 2 servos worth of space under the front clip - ideal for bags!
BTW, you can't be more than ½hour from me - I live in Penn, along the A404.

 

[Brett James-McCall]

Trevor,
The solution is either new servos, with the distinct possibilty that they will go the same way, or ditch the servos completely and fit multi-pot high performance front brakes - Wilwood, HiSpec, AP. The multiple pots replicate the servo effect.

Tony,
I thought the solution was a pedal with a a higher ratio say 5:1 or 6:1 matched with the correct master cylinder?

Brett

 

[Tony Hunt]

Tony,
I thought the solution was a pedal with a a higher ratio say 5:1 or 6:1 matched with the correct master cylinder?

Brett

Hi Brett,
I suppose it is, but I found I didn't need to change my pedal ratio or master cylinder, and got fade-free brakes as an added bonus. I'm not sure you'd get acceptable pedal pressures and travels just by adjusting the setup.
I should add that a balance bar is a distinct advantage to compensate if you don't do anything to the rears.
I've often wondered how effective the servos were anyway.

 

[Paul W]

To echo Tony's comments - I too removed the servos and fitted new calipers all round - pedalbox and master cylinders all still the original items and the brakes work well.

 

[Brett James-McCall]

Sorry for the slight highjack.

Tony, did you change pad material as well when you changed the calipers? I'm interested, that is all, as mine is only theory as I'm still building. I will get there one day, honest I thought the original GTD was around a 3:1 ratio or something?

 

[Dave Bilyk]

Trevor mine is a DAX, but I had similar issues, cleaned up the shuttle valve bore, got new seal kits, but still had problems, so I moved to a servo less setup. My pedal was already a 6.25 ratio, but I ditched the standard Granada / Scorpio brakes for Wilwood/Hispec, so I am completely with Tony on this one.

regards

Dave

 

[Trevor Skedge]

Tony,

Thanks for the reply and yes you are about 30 mins away. I live between Rickmansworth and Northwood by Ye Olde Greene Manne pub if that means anything to you.
Interestng that you can do away with the servos and go for bigger brakes. Any recomendations and are there any easy/direct replacements and apart from Tornado where can I find these. Anyone fitted Hi-Spec or Willwood and if so which ones? I assume these would be a common ford fitment and readily available?.
Thanks all for your input, always welcome.

Trevor.

 

[Brett James-McCall]

Trevor,
Assuming you are running 17s, Rally Design do a kits here: Professional Motorsport Parts, Spares & Rally Equipment from Rally Design

Hi Spec do kits here for 15" upward here, look under Ford Mk2 Granada: http://www.hispecbrake.co.uk/Conversions/All%20front%20pages/START%20ford.htm

I think Andy does some upgrades as well.

Just remember to upgrade your rear pads as well.

The other option is to buy some caliers and get a machine shop to make some bells and mounts. I did mine with AP fronts bought from a forum member.

Brett

 

[Trevor Skedge]

Brett,

Shame the Hi-Spec site doesn't give prices or at least they are not working at the moment and the Rally Design setup is no good for me as I am running 15 inch wheels at the currently. Maybe I will have to consider 16 or 17 inch wheels first. Pricey way of upgrading and solving an iffy brake servo setup.

Trevor.

 

[Brett James-McCall]

Prices are:

1/ Full Kit (any colour caliper) - £581.15 + VAT + Delivery

2/ Econ Kit (no hoses, fluid or pads, Silver only) - £409 + VAT

You could always build your own kit from RD. They do bells etc which will help in the process. Probably come to about £600+VAT before maching and pads etc

Brett

 

[Trevor Skedge]

Just looking at the prices on the Rally design site and taking into account new wheels and tyres it looks like £3.5k plus for the conversion, but that is for both front and rear. Andy does a 6 pot front conversion for the 15 inch wheels at £1245 plus VAT but that would still leave me with 15 inch tyre problems and a rear brake upgrade to source. guess what I need is a secondhand set of 17 inch wheels and tyres. Anybody?

Trevor.

 

[Brett James-McCall]

Trevor,
Why would this leave you with 15 tyre problems. Avon do a great set of 15s?

Brett

 

[Dave Bilyk]

Trevor,
I posted details of my setup which got the maximum disc size and piston area into the 15" wheels, if you go to my user profile and look for my posts you will find it. I looked at 6 pots but they were low on total piston area compared to 4 pots, so I ended up with Wilwood 4 pots at the front (largest total piston area I could get) and Hispec handbrake 4 pots at the back.


Dave

 

[Andy Sheldon]

Trevor

I have some used 17" wheels that may be available and also 4 and 6 pot brake kits for front and rear.

Our brake kits will fit 15" wheels

If you decide to fit bigger brakes do not remove the servos.

Thanks

Andy

 

[Tony Hunt]

Trevor,
I used Wilwood 6-pot Superlites on 300mm discs with Wilwood 150-8855K Smart pads at the front and kept the Ford Scorpio vented discs with Quinton Hazell BP368 pads at the back. I know that this will fit inside a 15" wheel as Paul Brameld has an identical setup in that wheel size.
This was done with the express intention of doing away with the servos and works well. When the brakes are hot, they're magic, but the pads do need bedding in initially.

 

Trevor,
I have a KVA but the issue is pretty much the same. Apart from Andy's tried and tested formula, you can buy the parts from Rally design. I have 320 mm disks front and back, with 4-pot Superlite to the front and 4-pot Dynalite on the back inside 15" wheels. I had to get some machining done by Brian Magee, who also remodelled my pedalbox to give a 6 1/2:1 ratio and balance bar. All the Granada bits went in the bin. Oh, and no servos !

Tony.

 

[Trevor Skedge]

Does anyone know if the caliper described as an M16 fits straight on to my granada MK2/Tornado setup?. I would have thought if this was the case then I could buy Wilwood/Hi-Spes M16 calipers and new discs for a fresh setup.

Trevor.