power assisted braking? ms57 brake upgrade

[jeffro ra28]

Hi there.

I am smack bang in the middle of a brake upgrade on my ms57 wagon.

Plans are to use uzs131 front discs, calipers, lower ball joint and stub axle. should be bolt in from what i have compared so far

Just a quick question tho. Could any one think of any problems i may have using a 76/77 celica brake booster with the uzs131 model calipers and perhaps rigging up rear drums to it aswell?

I only chose celica brake booster because they are nice and small and i have a few of them lying around. Oh and only uzs131 brakes because they are lying the back yard from the halfcut.

Edit: may i also add that the uzs131 stub axles are slightly offset compared to the 0 offset ms57 ones. I am hoping that the ball joints will cater for this extra offset. Would anyone like to share there thoughts?

Open to any suggestions, comments, questions. Thankyou.

[Earlyrolla]

Things to look out for are the displacement of the master cylinder, i.e the displacement over the stroke of the master cylinder is adequate for the brake calipers used, and the size of the bore of the new master cylinder compared to the bore of the standard master cylinder used with the calipers from the original vehicle.

Running a smaller bore on the master cylinder results in a higher line pressure for a given force applied to the brake pedal (Pressure = Force / Area, smaller area for the same force equals higher pressure) so this can lead to premature brake lock-up.

As you have said, you will need to run rear drums if using the original RA23 master cylinder. Drum brakes have a non-return circuit so that the master cylinder for drum brakes is different to that for disc brakes.

You will also need to run a proportioning valve between the front and rear brakes to minimise rear wheel lock up. The tendancy for rear wheel lock up will depend on the size of the rear wheel cylinders.

Hopefully this info is helpful to you

[jeffro ra28]

Thanks!

As you can probably tell. im a newb.
I also tinkered with the idea of using the uzs131 brake booster. but the wonders of ABS come into the eqaution and im not quite ready for that. Besides needing a computer to run them!

[TheStitt]

If you want a realy easy option run the brakes from a MS112, 123. you just unbolt from either of the later model cars including discs,stubs, ball joints, outer tie rod ends, and bolt into your car.

I would probably run the MS112 booster. If you have an auto with braket it shuold fit up against the fire wall with no real probs as one does in my dads MS55.

You could also run the m/c with a remote booster. This is what i doi I run my pbr front calipars with a VH40 and run my MS112 rears un boosted

I have plenty of more info and other ideas but now have to work.

Stitt

[jeffro ra28]

Thanks Stitt,
I can probly get an ms123 booster. Would this be the same as a ms112?

[gianttomato]

On my MS46, I used an Aussie built KE3x booster (PBR) and a Commodore 15/16" master cylinder. The master cylinder bolt pattern is convenient as you could use an earlier Falcon 1" one. Also, because there are so many drum brake and disc brake rear end Crumpodore variants, it's easy enough to get ones with or without a pressure relief valve in the master cylinder as required.

I did also make an adaptor block - this allows the booster to be mounted to the block and the block could then be mounted to the firewall. It was a tidy way to make 4 holes go into two.