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Knackered brake servo/booster


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As per title, I have a knackered servo booster unit on my 1984 S3 NA. It is no longer holding or even able to vacuum up.

Hoping someone here can give leads as to who might rebuild them or sell them new/used.

TIA

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In the UK - Home (northwestclassic.co.uk)   

NB I think the Turbo manual is wrong (my edition is).   It states the unit is a Supervac type 28.  Based on size I reckon its the larger (unfortunately rarer) type 38.

I assume you have checked its not just an issue with the non-return valve or the vacuum line?   There is also an air seal that sits between the master cylinder and the servo, which is an easy DIY change.   (I did mine a few weeks ago due to losing vacuum).  

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I can imagine this to be tough to get repaired in SEA. There’s no cottage industry for repairs like this unlike in the UK. Perhaps you have a better chance in Malaysia but in Singapore it’s virtually impossible to find a repair service Eric. My original servo in my 83 turbo is long gone. Some PO chucked it. I have a (presumably) Camry servo in it and it works fine for now. A while ago I bought a more correct, new unit from PNM but I have not fitted it yet. Came at a price though. I think I paid near 200£ for it iirc. For peace of mind I added an electric vacuum pump and a small reserve tank to my setup. Great braking now including backup. Good mod in my view.

8C3BDF71-9208-4FD9-A405-3F98701E4847.jpeg

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Posted (edited)
8 hours ago, 910Esprit said:

In the UK - Home (northwestclassic.co.uk)   

NB I think the Turbo manual is wrong (my edition is).   It states the unit is a Supervac type 28.  Based on size I reckon its the larger (unfortunately rarer) type 38.

I assume you have checked its not just an issue with the non-return valve or the vacuum line?   There is also an air seal that sits between the master cylinder and the servo, which is an easy DIY change.   (I did mine a few weeks ago due to losing vacuum).  

Checked and rechecked. Hissing noise comes from within.😭As you suggested, could be the air seal between the MC and servo. Worth a check, but where can I purchase spares?

Edited by ekwan
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Ebay is full of them.   EG here is a NOS item.  VOLVO 122/122S (SOME)144,145 BRAKE SERVO REPAIR KIT SP2651/1 NEW OLD STOCK | eBay  Just search on things such as 'girling supervac' or 'girling servo kit'  Can you see the rubber disc with the metal washer?   This is the seal which may have failed in yours.   That's more likely than the main diaphragm.   There is also an internal valve that could be the issue, but that's not user serviceable.  

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  • 1 month later...

I am also looking for a new servo for my '82 Esprit Turbo. 

Info I have found so far

Lotus No. A075J6080F

Girling No. 74049019  superseded by 74049164

It is a Girling Supervac Type 50  9"

Fitted also to early Excel and late Eclat

'86 UK Ford Capri Lazar 2 lt   but with a different connecting rod to the peddle.

'83-'89 Land Rover County 110 Non-ABS  but with a different stud mounting pattern ( earlier models with 7" servo have same pattern)

 

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Interesting, mine (84 Turbo) definitely isn't a Supervac 50  - The bolt pattern is different (50=oblong, 28/38=square) and there would not be room to fit a '50' without it fouling bodywork.  Based on the Girling literature and measurements mine appears to be a Supervac type 38. 

 

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5 hours ago, 910Esprit said:

Interesting, mine (84 Turbo) definitely isn't a Supervac 50  - The bolt pattern is different (50=oblong, 28/38=square) and there would not be room to fit a '50' without it fouling bodywork.  Based on the Girling literature and measurements mine appears to be a Supervac type 38. 

 

Looking at the parts list, it could be one of two fitted. Vastly differing mounts. 

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6 hours ago, viz139 said:

I am also looking for a new servo for my '82 Esprit Turbo. 

Info I have found so far

Lotus No. A075J6080F

Girling No. 74049019  superseded by 74049164

It is a Girling Supervac Type 50  9"

Fitted also to early Excel and late Eclat

'86 UK Ford Capri Lazar 2 lt   but with a different connecting rod to the peddle.

'83-'89 Land Rover County 110 Non-ABS  but with a different stud mounting pattern ( earlier models with 7" servo have same pattern)

 

Perhaps this solution...... 

...taking note that the new clevis is shorter, but adjustable and removable. So fabricating a completely new clevis to suit is likely to be an easier alternative.

 

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  • Gold FFM

I replaced the servo in my Eclat Excel with a Land Rover STC1816. Which corresponds to a Supervac type 28 instead of the type 38 Lotus used, so a slightly smaller diameter. The stud pattern is the same, no need to modify the bodywork. I did have to modify the connecting rod to the pedal. The Land Rover booster came with an eye instead of an adjustable fork like the Lotus. I cut the eye off and had a piece of threaded bar (M8) welded on so I could refit the fork and adjust as necessary. I've been using the Excel like that for some years, including our recent trip for Lotus in the Peak, and the brakes have been fine, certainly not too heavy.

Filip

I have made many mistakes in my life. Buying a multiple Lotus is not one of them.

 

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18 minutes ago, Escape said:

I replaced the servo in my Eclat Excel with a Land Rover STC1816. Which corresponds to a Supervac type 28 instead of the type 38 Lotus used, so a slightly smaller diameter. The stud pattern is the same, no need to modify the bodywork. I did have to modify the connecting rod to the pedal. The Land Rover booster came with an eye instead of an adjustable fork like the Lotus. I cut the eye off and had a piece of threaded bar (M8) welded on so I could refit the fork and adjust as necessary. I've been using the Excel like that for some years, including our recent trip for Lotus in the Peak, and the brakes have been fine, certainly not too heavy.

Filip

I guess Supervac 28, 38 & 50 will give different degrees of force magnification. 28 less, 50 more and 38 somewhere in between. 
 

Does anyone know if the stud pattern is the same for the 28, 38 and 50?

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  • Gold FFM

According to the manual, the 28 and 38 both have an assist ratio of 2.2:1, but the 38 has a greater range.

28 and 38 have the same square mounting pattern, 50 has a rectangular pattern, like Land Rover STC2878.

I have a manual, but it's too big to post, you can download from https://www.dropbox.com/s/uiadlsthawrrre3/GirlingSupervac.pdf?dl=0

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I have made many mistakes in my life. Buying a multiple Lotus is not one of them.

 

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12 hours ago, viz139 said:

I am also looking for a new servo for my '82 Esprit Turbo. 

Info I have found so far

Lotus No. A075J6080F

Girling No. 74049019  superseded by 74049164

It is a Girling Supervac Type 50  9"

Fitted also to early Excel and late Eclat

'86 UK Ford Capri Lazar 2 lt   but with a different connecting rod to the peddle.

'83-'89 Land Rover County 110 Non-ABS  but with a different stud mounting pattern ( earlier models with 7" servo have same pattern)

 

Girling Supervac 50 = Land Rover STC2878???

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  • Gold FFM
1 hour ago, ekwan said:

Girling Supervac 50 = Land Rover STC2878???

Yes, what I can find (through Land Rover) describes STC2878 as a type 50 (without reference to Girling or Supervac).

I have made many mistakes in my life. Buying a multiple Lotus is not one of them.

 

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Girling Supervac 50 is a range of servos with slightly different mounting and connecting options.

They are all 9" diameter sealed units.  The Girling Part No. seam to always start with 7404****

They come in at least two different stud patterns and several different clevis pin attachments  . 

If you look at the picture on the PMN servo you will see were they have added an adapter plate to change the stud pattern from what is probably a Landrover servo.

https://www.pnmparts.co.uk/esprit/esprit-s3-turbo-80-87/esprit-s3-turbo-80-87-j/lotus-servo-6080

The clevis pin adapter on the Esprit attaches to the Supervac on a 5/16UNF rod, does anybody know what the is thread on ST2878 ?

 

I created this from my own servo

BRAKE SERVO BOOSTER.png

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  • Gold FFM

STC2878 is described as 'type 50', so likely a Girling Supervac 50.

The mounting studs are M8, I can't find a reference for the connecting rod.

Girling does mention that the same servo will have different connecting rods depending on manufacturer.

I have made many mistakes in my life. Buying a multiple Lotus is not one of them.

 

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3 hours ago, viz139 said:

Girling Supervac 50 is a range of servos with slightly different mounting and connecting options.

They are all 9" diameter sealed units.  The Girling Part No. seam to always start with 7404****

They come in at least two different stud patterns and several different clevis pin attachments  . 

If you look at the picture on the PMN servo you will see were they have added an adapter plate to change the stud pattern from what is probably a Landrover servo.

https://www.pnmparts.co.uk/esprit/esprit-s3-turbo-80-87/esprit-s3-turbo-80-87-j/lotus-servo-6080

The clevis pin adapter on the Esprit attaches to the Supervac on a 5/16UNF rod, does anybody know what the is thread on ST2878 ?

 

I created this from my own servo

BRAKE SERVO BOOSTER.png

I believe M10. Taken from another forum topic

 

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