Series 3 Upgrading to Vaccumn/servo brakes

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onecelledcreature

onecelledcreature

Active Member
Posts
280
Location
Cheshire
Hi all,

I'm looking at upgrading the single line brakes on my 88 to duel line with a servo. I've found the parts for a second hand servo pedal from (i think) a 109.
parts include the pedal box & servo, master cylinder and a tank.
Photo of parts
AkVjJPTl.jpg

Who do i get the vacuum supply to run it?

engine is a 75 2.25 diesel suffix c.

if i look into using a 12v pump what is involved? do i need to be aware of the pumps input/output.
I'm not really clear on what i need to be researching to make this work.

cheers guys
 
So you're not sure what you are doing BUT you want to work on your brakes.... Cool.

Aaaanyway With a 2 1/4 diesel the butterfly in the inlet manifold has, to be set spot on OR you'll be getting lots of smoke AND not much vacuum... You'll be far better off with a electrical vac pump of a lesser vehicle.OR an alternator with a, vac pump on the back (be wary though as some require an oil supply/drain.
The inlet/outlets are usually marked BUT it's easy to suss out even if not as only one port should provide a vacuum.
Powered from a supply that's on with the ignition otherwise you'll be in flat battery territory
 
What he means is that you need to connect the vacumn tank to the engine inlet manifold. Diesel engines do not create their own vacumn so that is why there's a vacuum manifold to create it. It should connect with a jubilee clip. I've changed to petrol which connects to the inlet at the carburetor. Try to get hold of a workshop manual, you seem to have the basic parts .
 
mistericeman said:
So you're not sure what you are doing BUT you want to work on your brakes.... Cool.

Aaaanyway With a 2 1/4 diesel the butterfly in the inlet manifold has, to be set spot on OR you'll be getting lots of smoke AND not much vacuum... You'll be far better off with a electrical vac pump of a lesser vehicle.OR an alternator with a, vac pump on the back (be wary though as some require an oil supply/drain.
The inlet/outlets are usually marked BUT it's easy to suss out even if not as only one port should provide a vacuum.
Powered from a supply that's on with the ignition otherwise you'll be in flat battery territory
Click to expand...
Cheers. I'm only looking for pointers. I'm fitting brakes regardless, but I'm trying to build up some research on improvement options.
If I went down the vac pump route are there variations in the supply that matter or minimum / maximum ratings on the pump that need to be considered?

Don't worry I'm not biting the bullet yet. But Im putting some thought into improving the braking
 
Forget the dreadful butterfly effort and the tank. Fit an electric vacuum pump triggered off the brake light switch via a relay.
I used a Hella U28 (badged as a Volvo part) Check out ebay I bought mine some time ago from someone in Holland who was selling them new with a relay and diagram for around £70.
Pros. Good brakes with instant servo
Servo brakes with a dead engine providing the ignition is on. Useful if being towed or you stall.
Fitting the pump is simple and takes just 1 1/2 to 2 hours maximum.

Cons.You can hear the servo pump working when your foot is on the brake, annoying if you tend to hold the car on the foot brake in traffic. I never do so not an issue.
 
I think the butterfly and tanks ok if set up correctly as per manual. And keeps thing a bit more original But I like the idea of an electric vac.
Never thought to go that route when doing mine.
 
Yes the butterfly/tank set up can be made to work. However finding one that the spindle to pivot hole in the inlet isn't knackered is the hard part. Before fitting my electric pump I made a new spindle and bushed the casting to eliminate air leaks (helps being a toolmaker with a lathe and mill at home) It is still a chase around eliminating years of wear in the throttle linkage to get them to work correctly. As I said £70 and a couple of hours and the job is sorted forever.
 
divie said:
Forget the dreadful butterfly effort and the tank. Fit an electric vacuum pump triggered off the brake light switch via a relay.
I used a Hella U28 (badged as a Volvo part) Check out ebay I bought mine some time ago from someone in Holland who was selling them new with a relay and diagram for around £70.
Pros. Good brakes with instant servo
Servo brakes with a dead engine providing the ignition is on. Useful if being towed or you stall.
Fitting the pump is simple and takes just 1 1/2 to 2 hours maximum.

Cons.You can hear the servo pump working when your foot is on the brake, annoying if you tend to hold the car on the foot brake in traffic. I never do so not an issue.
Click to expand...
Mine doesn't have a suitable throttle for this, so this is the route i will look into, i'll keep a lookout for a suitable pump.
I saw a mention of fitting 11" brakes, is it necessary because of the increased power or does it not matter too much outside of better stopping.

disc would be lovely, but the most affordable ones i've seen use non standard discs and parts which costs more in the long run.
 
Fitting a servo will not improve the outright stopping power of brakes. It will considerably reduce the effort required, the 11" brakes up front do improve things.
Carefully set up they are very good unless submerged in water this is where the disc scores over the drum.
 
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