[clem430]

I have an 82 model sierra, with a 1.3 and front disk brakes. i'm wondering if there is any advantage to upgrading the master cylinder to a boosted one. off a later model sierra or something. The brakes work ok, but the have no feel to them. Just wondering if its worth it or not, and what would need to be done?

[steak_knife]

clem430 wrote:

I have an 82 model sierra, with a 1.3 and front disk brakes. i'm wondering if there is any advantage to upgrading the master cylinder to a boosted one. off a later model sierra or something. The brakes work ok, but the have no feel to them. Just wondering if its worth it or not, and what would need to be done?

True??

I know guy's that get rid of booster's so thay HAVE feel.. (race zook's)

Tis not just a bolt on job, booster to your car that is..

[clem430]

yeah not much feel at all, and i thought a boosted master cylinder would help and give me a bit more stopping power. I always thought the one litres had drums on the front standard, so the standard master cylinder wouldn't handle the discs that.
But i'm no mechanic so i could just be talking rubbish, and what needs to be done to fit a later model sierra booster instead of the standard cylinder?

[steak_knife]

Either put a new fire wall in (behind booster) or strengthen it heap's (behind master cyl ), The bolt pattern on the 1lt fire wall is different to the 1.3's and not as strong.

I used to run a 1.3 swift master non boosted (on a 1.3 n/t), booster's wont give you more stopping power, just make the peddle lighter..

[31zook]

subaru do great job or stopping 35s

[clem430]

Yeah thanks, thats what i wanted to know, a fair bit of work. but would a master cylinder off a later model be better because it would be designed to run disk brake fronts or is there no difference in the cylinder itself?

[tanshi]

1 litre sierras did come with disks on the front.

[steak_knife]

tanshi wrote:

1 litre sierras did come with disks on the front.

I had a 1lt that had to be converted to disc to do a 5k transplant, DOT were not happy with drum on the front.

[v.w.dave]

I have been looking for it but cant find it there is some american forum that had a list of different master cyl upgrades. For the life of me I cant find it. I think it was a early mitsu lancer master cyl would bolt right up to the old sierra. it gave more value making the disc convert feel and stop better. Someone on here will know the forum I just for the life of me cant find it. Its the same pic list of how to do the Merc highsteer convert.

[Rusho]

v.w.dave wrote:

I have been looking for it but cant find it there is some american forum that had a list of different master cyl upgrades. For the life of me I cant find it. I think it was a early mitsu lancer master cyl would bolt right up to the old sierra. it gave more value making the disc convert feel and stop better. Someone on here will know the forum I just for the life of me cant find it. Its the same pic list of how to do the Merc highsteer convert.

Didn't you post a link for the Merc high steer?? I remeber looking through the site. Can't remember either

[MrRocky]

just converted my 1ltr to boosted brakes and it was a major pain in the ass with the 1.6 multipoint fitted. Needed to swap to a 1.3 brake and clutch box, and cut a bigass hole in the firewall to suit the back of the booster. Now it is awsome and definately worth it, but i rate the difficulty level up there.

[Gwagensteve]

The common master cylinder upgrade for 1.3 sierras with boosted brakes is the 1 1/16" forester turbo cylinder. It's a bolt up but needs the push rod length adjusted.

I'm running one of these cylinders in my 1.0. To fit it the bolt pattern had to be redrilled on the cylinder and the hole in the firewall opened up a bit. It's possible to run all sorts of cylinders - it's really only the bolt pattern and pushrod length that's the issue.

Pedal effort is higher than with the sierra cylinder, but it stops BEAUTIFULLY. (I have sierra front calipers all round) and I'll add my car is very heavy for a sierra with sierra diffs. Increasing cylinder diameter increases pedal effort but reduces pedal throw. I'm toying with lowering my pivot point so I increase leverage to reduce pedal effort.

I also have a spectacularly firm pedal. (I have braided lines all round) It's just amazingly high and hard. I jumped in a stock 1.3 the other day and nearly died when the pedal just sunk towards the floor.

The key thing to remember is that boosters kill feel and (which is why there are very few boosted race cars) and that boosters do not improve brake performance, they only reduce pedal effort.

I'm in no hurry to add a booster. It won't increase feel or reduce stopping distance.

Steve.

[clem430]

Thanks heaps for the info guys. looks like i might have to go hunting for a forester master cylinder at the wreckers when i get some spare time from uni.
Thanks again everyone for the info