New SAAB Servos for sale
Discussion
There is a German parts supplier selling New PSA314 Brake Servo (ie the SAAB set up) on the German Ebay site, www. ebay.de
Search for item number 131153694013
Might be of interest to someone, there is only one SNAG.
They wont ship outside Germany (I asked) so you need to have a German pal and you have an option a new SAAB servo for about 189GBP?
Search for item number 131153694013
Might be of interest to someone, there is only one SNAG.
They wont ship outside Germany (I asked) so you need to have a German pal and you have an option a new SAAB servo for about 189GBP?
When i was looking for my replacement Saab servo a couple of months ago I thought I found it and the Fiesta alternative on a few car parts web-sites. They all turned out to be fronts for a German site and indicated that they were in stock. After I ordered, they advised that they were not in stock - so could be the same source. However, they were good about returning the money without quibble.
Hi Stuart,
After a lot of digging I sourced one in the possession of a guy called Hans in Holland - but he said it was his last one.
I have heard talk of Ford Ka ones recently but not sure if they are OK. the other way is to use the part number for the Fiesta one and try a local parts supplier as they may be able to find one
Do some googleing of old S forums for info:...I found this useful: http://www.pistonheads.com/gassing/topic.asp?h=0&a...
After a lot of digging I sourced one in the possession of a guy called Hans in Holland - but he said it was his last one.
I have heard talk of Ford Ka ones recently but not sure if they are OK. the other way is to use the part number for the Fiesta one and try a local parts supplier as they may be able to find one
Do some googleing of old S forums for info:...I found this useful: http://www.pistonheads.com/gassing/topic.asp?h=0&a...
Have these guys refurbish your old one:
http://www.jlspares.com/contact.htm
It'll come back good as new.
http://www.jlspares.com/contact.htm
It'll come back good as new.
I guess I am going to get a bad reputation as a 'prophet of doom' but I simply cannot let that last comment go. It is VERY dangerous indeed to play around with brake servo/ master cylinder combinations like this. A smaller diameter master cylinder has a smaller swept volume for a given pedal travel, for that reason alone the brake performance WILL be altered. Unfortunately you may not find out in what way it is altered until too late. My advice has GOT to be, fit a combination with the same performance as the original. Is your life, and that of the person you might hit, not worth that? Have you notified your insurers that you have fitted a non standard brake operating system with unknown characteristics?
Sorry, but where life is very clearly at stake, I feel I have to say something.
Sorry, but where life is very clearly at stake, I feel I have to say something.
Blimey..... prophet of doom in deed! 
If you think about what a master cylinder does, it pushes a quantity of fluid along some pipes to operate some pistons at the other end, so....
slightly smaller bore = slightly more travel to move same quantity, mechanical advantage actually improved so less effort required?
Is this anymore dangerous, dodgey, life threatening than fitting different calipers ( a very common "mod") that with bigger or more pistons will require more fluid (greater pedal travel) to move the same distance?
Obviously taken to extremes the pedal would hit the floor before the brakes came on but if you consider the number of kit cars, specials, modified cars etc. out there and they are not persistently crashing nor killing people?
Now I know that an MOT is no proof that a car is safe nor roadworthy but one bit of an MOT that is effective is the brake test, if the car passes without the tester giving himself a hernia having to push the pedal so hard then the servo is doing something. Many modern cars are (imho) over-servo'd, virtually just looking at the pedal puts the brakes on !
Sermon over
If you think about what a master cylinder does, it pushes a quantity of fluid along some pipes to operate some pistons at the other end, so....
slightly smaller bore = slightly more travel to move same quantity, mechanical advantage actually improved so less effort required?
Is this anymore dangerous, dodgey, life threatening than fitting different calipers ( a very common "mod") that with bigger or more pistons will require more fluid (greater pedal travel) to move the same distance?
Obviously taken to extremes the pedal would hit the floor before the brakes came on but if you consider the number of kit cars, specials, modified cars etc. out there and they are not persistently crashing nor killing people?
Now I know that an MOT is no proof that a car is safe nor roadworthy but one bit of an MOT that is effective is the brake test, if the car passes without the tester giving himself a hernia having to push the pedal so hard then the servo is doing something. Many modern cars are (imho) over-servo'd, virtually just looking at the pedal puts the brakes on !
Sermon over
Sermon indeed! Not being a religious man I will certainly not take offence!!!
Forgive me please but I will go a little further:
A master cylinder has a certain diameter and a certain effective length. The swept volume is the product of the cylinder area and that length.The system in a particular car is designed such that the cylinder piston operates along the length of the cylinder as required with some margin in hand. Reduce the diameter for a cylinder of a certain length and the swept volume reduces disproportionately quickly.
There is one master cylinder and 6* slave cylinders on an S. (* 2 on each caliper and a single cylinder but with 2 pistons on each side of the rear.) Those slave cylinders each require a certain swept volume of fluid to operate correctly. Essentially that requirement is matched to the master cylinder.
So if the swept volume of the master cylinder is reduced it no longer matches the design requirements of the slave cylinders. It might APPEAR to work OK on test but consider a few more things:
In normal road use will the pedal travel be such that full braking is difficult to achieve in normal circumstances.
When the brakes are more worn the system should ideally bring the pistons fully back, but in practice the swept volume required can increase and there is a safety margin in the master cylinder capacity to cope with this.
Although it appears that a smaller cylinder diameter gives a mechanical advantage at the master cylinder that advantage is reversed at the slave cylinder and it become more difficult to exert the design pressure at the slave cylinder.
What happens if the speed at which the pressure is transferred from the master to the slaves changes. What would happen to the brake 'feel', would it make the brakes more or less likely to lock up in an emergency/when the road surface friction changes.
As brakes heat up there is an effect on the efficiency of the transfer of pressure through the brake fluid. Less fluid means this loss is greater. Get the brakes really hot and see how the pedal pressure changes.
We have a simple front/rear pressure adjustment device on the S. What happens if the fluid pressure exerted by the driver changes from design?
The fluid in the master cylinder is refilled as necessary by a very simple fluid non return system. Will it necessarily work as well if the foot pedal is not quite giving the same travel, or the pressure is not quite as designed?
Have a look through a manufacturers catalogue at the number of different combinations that are required to satisfy the various vehicles. Would the manufacturers make so many if there was not good reason?
If you change a significant component in your braking system, can you be SURE it will still work, in ALL circumstances, as it should do?
If not........
Return sermon over!!
Forgive me please but I will go a little further:
A master cylinder has a certain diameter and a certain effective length. The swept volume is the product of the cylinder area and that length.The system in a particular car is designed such that the cylinder piston operates along the length of the cylinder as required with some margin in hand. Reduce the diameter for a cylinder of a certain length and the swept volume reduces disproportionately quickly.
There is one master cylinder and 6* slave cylinders on an S. (* 2 on each caliper and a single cylinder but with 2 pistons on each side of the rear.) Those slave cylinders each require a certain swept volume of fluid to operate correctly. Essentially that requirement is matched to the master cylinder.
So if the swept volume of the master cylinder is reduced it no longer matches the design requirements of the slave cylinders. It might APPEAR to work OK on test but consider a few more things:
In normal road use will the pedal travel be such that full braking is difficult to achieve in normal circumstances.
When the brakes are more worn the system should ideally bring the pistons fully back, but in practice the swept volume required can increase and there is a safety margin in the master cylinder capacity to cope with this.
Although it appears that a smaller cylinder diameter gives a mechanical advantage at the master cylinder that advantage is reversed at the slave cylinder and it become more difficult to exert the design pressure at the slave cylinder.
What happens if the speed at which the pressure is transferred from the master to the slaves changes. What would happen to the brake 'feel', would it make the brakes more or less likely to lock up in an emergency/when the road surface friction changes.
As brakes heat up there is an effect on the efficiency of the transfer of pressure through the brake fluid. Less fluid means this loss is greater. Get the brakes really hot and see how the pedal pressure changes.
We have a simple front/rear pressure adjustment device on the S. What happens if the fluid pressure exerted by the driver changes from design?
The fluid in the master cylinder is refilled as necessary by a very simple fluid non return system. Will it necessarily work as well if the foot pedal is not quite giving the same travel, or the pressure is not quite as designed?
Have a look through a manufacturers catalogue at the number of different combinations that are required to satisfy the various vehicles. Would the manufacturers make so many if there was not good reason?
If you change a significant component in your braking system, can you be SURE it will still work, in ALL circumstances, as it should do?
If not........
Return sermon over!!
greymrj said:
Sermon indeed! Not being a religious man I will certainly not take offence!!!
Forgive me please but I will go a little further:
A master cylinder has a certain diameter and a certain effective length. The swept volume is the product of the cylinder area and that length.The system in a particular car is designed such that the cylinder piston operates along the length of the cylinder as required with some margin in hand. Reduce the diameter for a cylinder of a certain length and the swept volume reduces disproportionately quickly.
There is one master cylinder and 6* slave cylinders on an S. (* 2 on each caliper and a single cylinder but with 2 pistons on each side of the rear.) Those slave cylinders each require a certain swept volume of fluid to operate correctly. Essentially that requirement is matched to the master cylinder.
So if the swept volume of the master cylinder is reduced it no longer matches the design requirements of the slave cylinders. It might APPEAR to work OK on test but consider a few more things:
In normal road use will the pedal travel be such that full braking is difficult to achieve in normal circumstances.
When the brakes are more worn the system should ideally bring the pistons fully back, but in practice the swept volume required can increase and there is a safety margin in the master cylinder capacity to cope with this.
Although it appears that a smaller cylinder diameter gives a mechanical advantage at the master cylinder that advantage is reversed at the slave cylinder and it become more difficult to exert the design pressure at the slave cylinder.
What happens if the speed at which the pressure is transferred from the master to the slaves changes. What would happen to the brake 'feel', would it make the brakes more or less likely to lock up in an emergency/when the road surface friction changes.
As brakes heat up there is an effect on the efficiency of the transfer of pressure through the brake fluid. Less fluid means this loss is greater. Get the brakes really hot and see how the pedal pressure changes.
We have a simple front/rear pressure adjustment device on the S. What happens if the fluid pressure exerted by the driver changes from design?
The fluid in the master cylinder is refilled as necessary by a very simple fluid non return system. Will it necessarily work as well if the foot pedal is not quite giving the same travel, or the pressure is not quite as designed?
Have a look through a manufacturers catalogue at the number of different combinations that are required to satisfy the various vehicles. Would the manufacturers make so many if there was not good reason?
If you change a significant component in your braking system, can you be SURE it will still work, in ALL circumstances, as it should do?
If not........
Return sermon over!!
what happens when you cannot obtain original parts and only 'close approximations' are available?Forgive me please but I will go a little further:
A master cylinder has a certain diameter and a certain effective length. The swept volume is the product of the cylinder area and that length.The system in a particular car is designed such that the cylinder piston operates along the length of the cylinder as required with some margin in hand. Reduce the diameter for a cylinder of a certain length and the swept volume reduces disproportionately quickly.
There is one master cylinder and 6* slave cylinders on an S. (* 2 on each caliper and a single cylinder but with 2 pistons on each side of the rear.) Those slave cylinders each require a certain swept volume of fluid to operate correctly. Essentially that requirement is matched to the master cylinder.
So if the swept volume of the master cylinder is reduced it no longer matches the design requirements of the slave cylinders. It might APPEAR to work OK on test but consider a few more things:
In normal road use will the pedal travel be such that full braking is difficult to achieve in normal circumstances.
When the brakes are more worn the system should ideally bring the pistons fully back, but in practice the swept volume required can increase and there is a safety margin in the master cylinder capacity to cope with this.
Although it appears that a smaller cylinder diameter gives a mechanical advantage at the master cylinder that advantage is reversed at the slave cylinder and it become more difficult to exert the design pressure at the slave cylinder.
What happens if the speed at which the pressure is transferred from the master to the slaves changes. What would happen to the brake 'feel', would it make the brakes more or less likely to lock up in an emergency/when the road surface friction changes.
As brakes heat up there is an effect on the efficiency of the transfer of pressure through the brake fluid. Less fluid means this loss is greater. Get the brakes really hot and see how the pedal pressure changes.
We have a simple front/rear pressure adjustment device on the S. What happens if the fluid pressure exerted by the driver changes from design?
The fluid in the master cylinder is refilled as necessary by a very simple fluid non return system. Will it necessarily work as well if the foot pedal is not quite giving the same travel, or the pressure is not quite as designed?
Have a look through a manufacturers catalogue at the number of different combinations that are required to satisfy the various vehicles. Would the manufacturers make so many if there was not good reason?
If you change a significant component in your braking system, can you be SURE it will still work, in ALL circumstances, as it should do?
If not........
Return sermon over!!
also as said previously MANY upgrades use larger diameter discs and / or different calipers or even pad material but no changes to the master cylinder or servo No-one answers those questions
Edited by magpies on Friday 25th April 23:55
Edited by magpies on Friday 25th April 23:58
greymrj said:
There is one master cylinder and 6* slave cylinders on an S. (* 2 on each caliper and a single cylinder but with 2 pistons on each side of the rear.)
One piston per caliper 
greymrj said:
Have a look through a manufacturers catalogue at the number of different combinations that are required to satisfy the various vehicles.
Somehow I imagine a conversation a bit like this.....TVR : We're building a new "budget" sports car and will need some servo/master cylinders. what you got?
Supplier : Saab are struggling at the moment, we've over produced. They're a bit of a flaff with separate reservoir but can do you a "good deal"
TVR : Sounds perfect !
TVR Stu,
Maybe you are right. My watch list kept telling me one was still available but when you do a new search today they seem to all have been sold. They claimed to have 4 originally two adverised as for a SAAB 9000 2.0 and two for a 2.3 (or maybe just the same two?).
I have had the same experience as Auto Andy with other suppliers but this lot have actually shipped something as far as the German office of my employer. All I have to do is get hold of it in UK and we will see if it is the right part or not?
Maybe you are right. My watch list kept telling me one was still available but when you do a new search today they seem to all have been sold. They claimed to have 4 originally two adverised as for a SAAB 9000 2.0 and two for a 2.3 (or maybe just the same two?).
I have had the same experience as Auto Andy with other suppliers but this lot have actually shipped something as far as the German office of my employer. All I have to do is get hold of it in UK and we will see if it is the right part or not?
Hi Mike, yep, have to accept that my inability to count does rather undermine my credibility! 
However a few of the other bits I learnt when I took my Mech Eng still hold valid.;)
I am going to reassure you on one thing though. Your cynicism about TVR 'design' is even worse than mine! When researching the servo/master cylinder issue we did get help from TRW (the manufacturers)and it did show that the design parameters of the original brake operating system supplied by them (or Lucas as they were at the time) to SAAB, did EXACTLY match that required for the Sierra brake system to be used on the S.
That was the basis on which we then searched
for another match, through the literally thousands of combinations made by TRW
.
It is becoming a nice day, I am now going to give 'her' a bit of paintwork attention.
However a few of the other bits I learnt when I took my Mech Eng still hold valid.;)
I am going to reassure you on one thing though. Your cynicism about TVR 'design' is even worse than mine! When researching the servo/master cylinder issue we did get help from TRW (the manufacturers)and it did show that the design parameters of the original brake operating system supplied by them (or Lucas as they were at the time) to SAAB, did EXACTLY match that required for the Sierra brake system to be used on the S.
That was the basis on which we then searched
for another match, through the literally thousands of combinations made by TRW.It is becoming a nice day, I am now going to give 'her' a bit of paintwork attention.
greymrj said:
When researching the servo/master cylinder issue we did get help from TRW (the manufacturers)and it did show that the design parameters of the original brake operating system supplied by them (or Lucas as they were at the time) to SAAB, did EXACTLY match that required for the Sierra brake system to be used on the S.
That was the basis on which we then searchedfor another match, through the literally thousands of combinations made by TRW.
Richard, any idea why TVR did not use the Sierra servo & master cyl ?That was the basis on which we then searched
for another match, through the literally thousands of combinations made by TRW.Surely they would match the Sierra brake system a treat?
I would dearly love to know what it is that is fitted in my S1, as it bears no resemblance to either the SAAB or Fiesta set-up. The servo is "fatter" & deeper than the others, & the m/cyl has a cast body with the reservoir mounted on top, not remote as per the SAAB.
From the casting number on the side of the master cyl, I have established that it could be Mk 4 or 5 Cortina, or possibly Capri, but without stripping it all down to measure the bore size, I can't be sure. 13/16" or 0.812" is mentioned in one reference, but this is approx 20.62mm, not the 22.2mm our cars are purported to have. Is it really that critical? Shirley there must be some overlap either end of the working range of each installation.
There's a possibility it could also be Sierra I suppose, who knows?
I've got the Fiesta replacements, but the existing brake pipes will have to be changed as well, because no amount of "tweaking" would get them to fit.
Also I have no idea which servo link rod I would need to fit that would ensure full range of servo travel from the pedal. I'm reluctant to strip it all down & find myself stuck with vital parts unobtainable before the Eurotour, but I'm gonna have to bite the bullet soon......
greymrj said:
Hi Mike, yep, have to accept that my inability to count does rather undermine my credibility!
However a few of the other bits I learnt when I took my Mech Eng still hold valid.;)
I am going to reassure you on one thing though. Your cynicism about TVR 'design' is even worse than mine! When researching the servo/master cylinder issue we did get help from TRW (the manufacturers)and it did show that the design parameters of the original brake operating system supplied by them (or Lucas as they were at the time) to SAAB, did EXACTLY match that required for the Sierra brake system to be used on the S.
I presume EXACTLY to the S1 240mm discs / original calipers and the 9" drum brakes all with OE grade friction materials. However a few of the other bits I learnt when I took my Mech Eng still hold valid.;)
I am going to reassure you on one thing though. Your cynicism about TVR 'design' is even worse than mine! When researching the servo/master cylinder issue we did get help from TRW (the manufacturers)and it did show that the design parameters of the original brake operating system supplied by them (or Lucas as they were at the time) to SAAB, did EXACTLY match that required for the Sierra brake system to be used on the S.
What would you recommend for an S with upgrades of any nature away from the above?
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