Lightweight Brakes

[peter_m7uk]

Guys,

 

I'm just wondering about brakes at the moment. As the Lightweight is light (isn't it?!), I would imagine that no one has used a servo? But what about the Sierra deceleration valve? Searching the forum for comments on the 2B, some say they needed it and some say they didn't. Any experiences to report? Also, it looks like the Sierra master cylinder will not fit the Lightweight without cutting an enormous hole in the scuttle! What have people used to replace it and where did they get it from? How did you connect the brake pedal to the master cylinder - It seems that it will have to be very different to the method used on the Sierra? Hope you can help!

 

Pete

Edited February 11, 2008 by peter_m7uk

[Guest diyer]

I used a standard sierra master cylinder and no servo, and yes had to cut a slightly bigger hole in the scuttle.

 

Simon

[Guest Ad_W2001]

being a bit of a novice, the servo part is the big black vacuum thing with springs and god-knows-what-else inside? so we can ditch that and make a bracket for the actual master cylinder? Im getting onto this part soon too! yey maybe a couple of lightweights on the road

[peter_m7uk]

I used a standard sierra master cylinder and no servo, and yes had to cut a slightly bigger hole in the scuttle.

 

Simon

 

Hi Simon,

 

Thanks for the reply. So did you use the deceleration valve? If not, ever had a rear wheel lock-up?!

Also, how did you adapt the master cylinder for the Lightweight? It clearly has to go on backwards

relative to the Sierra, but there's a kind of plunger on the Sierra that goes through the servo and into

the master cylinder. Did you re-use that somehow, or have a totally different idea?

 

Cheers,

Pete

[peter_m7uk]

being a bit of a novice, the servo part is the big black vacuum thing with springs and god-knows-what-else inside? so we can ditch that and make a bracket for the actual master cylinder? Im getting onto this part soon too! yey maybe a couple of lightweights on the road

 

Adam,

 

That is indeed the servo. Makes life a lot easier and neater without that big ugly

lump in your engine bay!

 

Pete

[Guest gdc]

hi pete

i have not used the servo on my one , i am running smaller rear drums ie escort.

no deceleration valve needed because of the smaller drums.

but on dans that is yet to be tested (booking tommorow) has sierra drums and no deceleration valve so i will only know after test if needed or not.and no servo. the auto has a ka servo mounted on passanger side.

 

re the peddle box i am trying to find a photo

but the hardest thing to find and i got mine on ebay is a master cylinder , needs to be short as on my cars because of the second roll bar i mount under the scuttle the sierra one wont fit, and i bought it on what it looked like and its dimentions , i dont know what its from sorry.

the rod to drive the master from the peddle is a piece of round bar from another old master that fitted the dia into the master and then cut a thread on the peddle end rounded off the master end and clevis pinned to the peddle.resevour also cant be to tall.

dont forget if you cut a hole in the scuttle you will need to create a box on the back to maintain the firewall.

 

regards graham

pictures on big lees web site go to links and scoll down to lightweight pictures

[Guest diyer]

Hi Simon,

 

Thanks for the reply. So did you use the deceleration valve? If not, ever had a rear wheel lock-up?!

Also, how did you adapt the master cylinder for the Lightweight? It clearly has to go on backwards

relative to the Sierra, but there's a kind of plunger on the Sierra that goes through the servo and into

the master cylinder. Did you re-use that somehow, or have a totally different idea?

 

Cheers,

Pete

 

Ditch the deceleration valve, you don't need it. I fashioned a link rod between the pedal and master cylinder.

 

ps i am using standard sierra drums

 

Simon

Edited February 11, 2008 by diyer

[Guest Ian & Carole]

If you are using the Sierra pedal box and master cylinder without the servo fitted "Tiger" do a push rod for about £8.00.

 

Its a straight fit pedal - cylinder.

 

HTHs

 

Ian J

[Guest ScotMac]

See what i am using in the other thread i just put up on my new custom brakes. I know it very different than the Sierra setup you are asking about, but just though people might be interested:

 

http://community.rhocar.org/index.php?show...t=0#entry148240

[Guest salty_monk]

No valves on either of my cars, no probs with lock up. First one had more feel than the current one which is very sharp, slightly confusing as the first one was 2.0i brakes (big rear drums) & the current one is 1.6.

 

I do have 185 front tyres & 195 rears though.

 

Dan

[E.Hunt]

using standard sierra master cylinder without servo, had to make a plate up as the sierra m/cyl mounting holes are in a different place. not using the valve and normal drums on back. can't tell you if means the back will lock as I've not finished yet

 

pedal box

[Guest old_timbo]

205 tyres, large drums at rear, standard servo and master cylinder, standard sierra rear inertia valve mounted at about 30 degrees, standard front disks and calipers - my 2B locked up rears well before the fronts and was plain dangerous. Don't know how the original builder got it through the SVA. I've now fitted a variable bias valve in the rear brake line and the brakes can now be nicely balanced. I think Sierra Estates might have had different slave cykinders in the rear drums to give greater braking effect. My slaves had been renewed - not sure with what type, so maybe thats what caused my problem.

 

Tim

[Guest gdc]

hi

dans lightweight passed sva with standard sierra drums on rear with no bias valve, or acceleration or deceleration valve fitted.

 

regards graham