Brake Servo Sprint

[NigelTurner]

Hi All This may be a new or old topic depending on who is reading. I have a Sprint servo with Past parts for repair. It has a broken Bakelite disc. I cant find one anywhere. Does anyone know where I can get one or where a replacement part can be manufactured? Thanks for any help. Nigel

[tangocharlie1]

The club did have some but i believe you need to exchange your own unit, but if the bakelite is broken it is U/S. However Rimmers now stock Sprint Servos at a cost £.

[xvivalve]

Rimmers stock servos that can be made to fit a Sprint, they are not original Sprint servos. I don’t know first hand what needs to be done to adapt them but Ken Clarke does. There was also a thread on here about them.

Club stock rarely exceeds one unit and yes they are exchange with a £100 surcharge if your’s isn’t serviceable. The reconditioner currently has one unit I took in exchange and I’m waiting to hear if it is viable or not… With the exchange surcharge they were £270, but I’m anticipating a slight price rise.

We are still waiting on a prototype with an aluminium piston instead of Bakelite but it may prove too heavy for the vacuum available…

The cheaper option is to use an 1850 servo.

[new to this]

Rimmers stock servos that can be made to fit a Sprint, they are not original Sprint servos. I don’t know first hand what needs to be done to adapt them but Ken Clarke does. There was also a thread on here about them.

Club stock rarely exceeds one unit and yes they are exchange with a £100 surcharge if your’s isn’t serviceable. The reconditioner currently has one unit I took in exchange and I’m waiting to hear if it is viable or not… With the exchange surcharge they were £270, but I’m anticipating a slight price rise.

We are still waiting on a prototype with an aluminium piston instead of Bakelite but it may prove too heavy for the vacuum available…

The cheaper option is to use an 1850 servo.

Just an idea, could you get the piston made in hard plastic ?

Dave

[whydidistartthis]

Not actually seen one of these, but could it be possible to 3d print them?

[xvivalve]

Not actually seen one of these, but could it be possible to 3d print them?

No, it's been tried; can't get them smooth enough to hold the vacuum

[xvivalve]

Rimmers stock servos that can be made to fit a Sprint, they are not original Sprint servos. I don’t know first hand what needs to be done to adapt them but Ken Clarke does. There was also a thread on here about them.

Club stock rarely exceeds one unit and yes they are exchange with a £100 surcharge if your’s isn’t serviceable. The reconditioner currently has one unit I took in exchange and I’m waiting to hear if it is viable or not… With the exchange surcharge they were £270, but I’m anticipating a slight price rise.

We are still waiting on a prototype with an aluminium piston instead of Bakelite but it may prove too heavy for the vacuum available…

The cheaper option is to use an 1850 servo.

Just an idea, could you get the piston made in hard plastic ?

Dave

It would require tools to be made, which would be prohibitively expensive.

[new to this]

Rimmers stock servos that can be made to fit a Sprint, they are not original Sprint servos. I don’t know first hand what needs to be done to adapt them but Ken Clarke does. There was also a thread on here about them.

Club stock rarely exceeds one unit and yes they are exchange with a £100 surcharge if your’s isn’t serviceable. The reconditioner currently has one unit I took in exchange and I’m waiting to hear if it is viable or not… With the exchange surcharge they were £270, but I’m anticipating a slight price rise.

We are still waiting on a prototype with an aluminium piston instead of Bakelite but it may prove too heavy for the vacuum available…

The cheaper option is to use an 1850 servo.

Dose the Bakelite piston always brake in the same place ? have you got a picture of the Bakelight piston ?

Dave

[xvivalve]

The piston shatters, it’s not a common break point.

I don’t have a photo’ of a piston

[Richard the old one]

Would the piston be the same as the piston inside a 1500 servo as if so we could consider cannibalizing a 1500 servo as I believe they are more common?

[xvivalve]

Would the piston be the same as the piston inside a 1500 servo as if so we could consider cannibalizing a 1500 servo as I believe they are more common?

They are similar, but unfortunately a different diameter. Both the 13/1500 and 1850 servos share a piston with other makes and models but the Sprint is almost unique to the model; it's only the fact that some early Fords use the same piston that makes the research into alternative fabrication even halfway viable!

The phenomena of the piston shattering is also seemingly isolated to the Sprint and associated Fords, usually as a result of the pedal being pressed on a dry system

[WDM242N]

I've been meaning to post something to this ilk recently, so might as well put it here!
Having dismantled a couple of broken ones recently, I'm not so sure it's a dry system that breaks the piston. I wonder if rust accumulates in the bottom of the case, and if left to sit for a period of time hardens up, and then the next time the pedal is pressed, it jams and breaks the piston.
The pistons i have broke around a third of the way up, and don't seem able to come into contact with any part of the case, other than the centre. And i don't see that this would cause the break.
If this is the case, there could plenty of good servos with rusty insides waiting to break.