9 replies to this topic

[rendersonique]

Hi there.
I have bought a universal Lockheed type brake servo made by Powertune after I have had a few difficulties with the one fitted to my MK2 cooper S. I have just read the instructions and it says that the part number of my item is RLE72696. the listing at the back of the instruction list shows all models of cars and there corresponding servo kit part number. The one for my car should be RLE2696. I called the company and they said it was to do with the boost ratio of the sever. Apparently the one I have is a 1.90:1 ratio, where as the one I should have is a 1.60:1. They said it would just provide more power to the brakes. My questions are,

1, Has anybody else fitted one of these servos instead of the actual one for the car?
2, Will the pressure in the inlet manifold of my twin carb set up provide the necassary boost to opperate this servo?
3, And am I likley to damage any seals in the caliper pistons and rear brake cells?

Basically is it safe to fit?

Edited by rendersonique, 28 June 2011 - 02:31 PM.

[tommy boy]

Hi
I fitted one of these to my clubby 1275 gt last year, and got really good results. The difference from without to with was brilliant. This type of brake servo was all that was availiable back in my cortina days and we used them all the time. I don`t think there will be a problem. You will enjoy the extra braking ability. Don`t forget to fit the inline valve in the servo air pipe to stop it filling with fuel vapour. ( fit it the right way round too).
Hope this helps

[rendersonique]

Hi
I fitted one of these to my clubby 1275 gt last year, and got really good results. The difference from without to with was brilliant. This type of brake servo was all that was availiable back in my cortina days and we used them all the time. I don`t think there will be a problem. You will enjoy the extra braking ability. Don`t forget to fit the inline valve in the servo air pipe to stop it filling with fuel vapour. ( fit it the right way round too).
Hope this helps

Hi
Thanks for the reply. My issue isn't really weather or not to fit, but the fact that its a 1.90:1 ratio and not a 1.60:1 ratio they have sent

[bmcecosse]

My advice - send it back for a refund, and spend the money on something useful instead... It's a small light car - it doesn't NEED a servo! Far better without.

[rendersonique]

My advice - send it back for a refund, and spend the money on something useful instead... It's a small light car - it doesn't NEED a servo! Far better without.

I wasn't asking wether or not my car needed a servo or not! My car is a MK2 Cooper S and was fitted as standard with a servo, and i want it to have a servo for authenticity. Please read my first post properly.

Edited by rendersonique, 28 June 2011 - 10:43 PM.

[bmcecosse]

Oh I did read it..... yes 1.9 ratio will be too much. You just need a servo with 1:1 ratio then if it's just for 'authenticity'

[rendersonique]

Sending it back. Just ordered the correct unit!

[Ethel]

It would have made no difference, the later remote servo on the Mk3 was 1.9:1. The manifold pressure would be the same, the difference is the in the ratio of the pistons in the servo. The pressure in the calipers will still depend on how hard you press the pedal; it will still require exactly the same amount for the same braking effect. Obviously the manufacturers have no control over how hard the driver can push the pedal so there'll be a huge safety margin.

[rendersonique]

It would have made no difference, the later remote servo on the Mk3 was 1.9:1. The manifold pressure would be the same, the difference is the in the ratio of the pistons in the servo. The pressure in the calipers will still depend on how hard you press the pedal; it will still require exactly the same amount for the same braking effect. Obviously the manufacturers have no control over how hard the driver can push the pedal so there'll be a huge safety margin.

Thanks for the response Ethel. Wasn't 100% sure and I did see another thread on another forum stating that a similar servo fitted to another mini had the issue of the brakes locking on fully when more than a small amount of pressure was used amking the car undrivable. Also, the one I have sent back only had 2 studs coming off the back of the servo spaced slightly wider than the existing bracket I have on the inner wing of my car. This would have meant that I would have had to make modifications I wasn't happy with. I have confirmend that the I should recieve today will have 3 studs and fit as a direct replacement.

Thanks again to all of those people that responded to this thread with CONSTRUCTIVE suggestions

[Ethel]

There was a craze of pulling the covers off the air valve on them. A bad idea in my view as you also lose the spring that keeps the valve opening in proportion to the pedal pressure.