Rt142 Corona Brake Booster Failure ?

[Des]

Hey Hey,

 

I have a RT142 Corona, Only had it for 1 month or so and ive noticed the brake pedal is very hard. The brakes don't fade at all and work great but my right leg is getting very buff.

 

Has the booster let go at some stage ?

 

PS: Its an Autogomagic aswell if its of any consilation.

[Trev]

If its the standard booster do you think that the mighty V6 would be pulling more vacuum and thats why its hard. (Its brakes i don't have a clue but i will try)

Edited May 26, 2007 by Trev

[Des]

Maybe but the brakes don't feel that much different with the engine off, Its slightly noticable but not much.

[love ke70]

get in car.

press foot down hard on brake pedal

start car.

 

does the pedal drop further?

 

the more the vac the more boost = the less effort.

[Trev]

get in car.

press foot down hard on brake pedal

start car.

 

does the pedal drop further?

 

the more the vac the more boost = the less effort.

 

I think thats the answer to the problem.

[Des]

Ok, Just went outside and held my foot on the pedal and started it up and the pedal dropped about 1 inch. Out of all the cars ive drivin this would be the hardest.

[Trev]

Ok, Just went outside and held my foot on the pedal and started it up and the pedal dropped about 1 inch. Out of all the cars ive drivin this would be the hardest.

 

I don't see anything wrong with it.

[Des]

Its very hard, My st141 is softer and has the same booster and master.

[Trev]

Its very hard, My st141 is softer and has the same booster and master.

 

And less cylinders making vacuum.

[Des]

get in car.

press foot down hard on brake pedal

start car.

 

does the pedal drop further?

 

the more the vac the more boost = the less effort.

So since its a 6 it should have more vaccum so it should be softer ?

[love ke70]

trev you mustnt understand. the more vacuum you ahve the less force you need on the brake pedal.

des, and no a 6 wont have more vaccum. more air flow but still around the same in/mg.

 

des, we have found the booster to be working.

hows the brake fluid?

 

if the fluid is good the calipers are gunged up and need to be stripped and cleaned.

[Des]

Fluid is clean, Pads are good but i havent pulled the calipers apart as of yet. Rebuild kit ?

[Trev]

trev you mustnt understand. the more vacuum you ahve the less force you need on the brake pedal.

des, and no a 6 wont have more vaccum. more air flow but still around the same in/mg.

 

des, we have found the booster to be working.

hows the brake fluid?

 

if the fluid is good the calipers are gunged up and need to be stripped and cleaned.

 

I don't see where i understood, Going by what Des has said all the others drop more toward the floor.

[love ke70]

probably because the calipers move more freely in all the others.

an inch is a decent amount

the hardness of the pedal is caused by a resistance to movement, not a excess of vacuum.

the test showed the booster is working so that is not the problem.

des, i never use rebuild kits.

have you pulled a caliper apart before?

 

my guess will be that behind the seal around the piston there will be a large collection of calcified brake fluid and this is causing the pistons to not want to move.

getting them apart is the hardest bit, best method i have found is doing them on the car clamp 3 of the four rubber lines, and pump pedal. this will push the piston out. clamp that line, unclamp another and repeat until all pistons are out.

this is made much more difficult with twin piston calipers i promise.

once apart just scrape all the shit out, if the seals are truly f@$ked replace them. if not just wack her back together and enjoy your braking.

one thing to remember is make sure u clean the sliders if not u might get a bias to one side.

[Corolla_Kid]

You can pop the pistons out using an air compressor by using the air blower gun into where the hose screws into the caliper.

worked well when i rebuilt my ke70 calipers.