Spongy Brakes - Page 2

spankle my wankle · 01-18-2010, 06:06 PM

well Im guessing its number 2 now cause I just rebled the MC and all the lines and its still traveling to far before its good stopping power.

rx4ur7 · 01-22-2010, 11:47 AM

Test for brake booster:
Checking without a tester. Check the 3 tests in order.
(1)
1-With engine stopped, depress pedal several times
2-Start engine with pedal depressed
3-The unit is good if the pedal moves down very slightly immediately after the engine starts

(2)
1 start the engine
2- stop the engine after it has run for 1 or 2 minutes
3- Depress the brake pedal by applying normal force
4- the unit is good if the stroke is long the first time the pedal is depressed and becomes shorter as the pedal is depressed repeatedly (as long as rear drum brakes are adjusted properly, to compensate for non-adjusted rears, apply e-brake fully before perfoming this test)

Note If the results of this next test are unsatisfactory, check for damage or improper installation of check valve or vacuum lines. If a problem is found make repairs then repeat test.

(3)
1-Start engine
2-Depress pedal by applying normal force
3- With pedal depressed, stop the engine
4-Keep pedal depressed for ~ 30 seconds
5-The unit is good if there is no change in pedal height.

If it is still pulling to the right, there is something wrong with the left front brake system.
If the pedal is rock hard, check for stuck caliper, wheel cylinder or improperly installed pad.

rx4ur7 · 01-22-2010, 11:57 AM

Now if you ran the master dry and you have air it it that is another issue.
84/85 factory MC's came with bleeders which should work. But there have been exceptions. If it does not you need to do one of these procedures.

1- bench bleed the master either by removing it and doing it in the vise or doing it in the car.
This next one can be done but can be tricky
2- open all 4 bleeders
2a- press the pedal to the floor quickly, hold it there
2b- close all bleeders
2c- release pedal slowly
repeat as needed.
(really helps to have 2 people on this one, can be done by one but is not fun. Trust me I know)

spankle my wankle · 01-22-2010, 10:11 PM

thanks ill def give that a try

01-22-2010, 11:57 AM	#18
rx4ur7 Rotary since 1972 Join Date: Nov 2008 Location: Tucson Posts: 231 Rep Power: 17	Now if you ran the master dry and you have air it it that is another issue. 84/85 factory MC's came with bleeders which should work. But there have been exceptions. If it does not you need to do one of these procedures. 1- bench bleed the master either by removing it and doing it in the vise or doing it in the car. This next one can be done but can be tricky 2- open all 4 bleeders 2a- press the pedal to the floor quickly, hold it there 2b- close all bleeders 2c- release pedal slowly repeat as needed. (really helps to have 2 people on this one, can be done by one but is not fun. Trust me I know) Last edited by rx4ur7; 01-22-2010 at 12:03 PM.

01-18-2010, 06:06 PM	#16
spankle my wankle Rotary Fanatic Join Date: Feb 2008 Posts: 185 Rep Power: 18	well Im guessing its number 2 now cause I just rebled the MC and all the lines and its still traveling to far before its good stopping power.

01-22-2010, 11:47 AM	#17
rx4ur7 Rotary since 1972 Join Date: Nov 2008 Location: Tucson Posts: 231 Rep Power: 17	Test for brake booster: Checking without a tester. Check the 3 tests in order. (1) 1-With engine stopped, depress pedal several times 2-Start engine with pedal depressed 3-The unit is good if the pedal moves down very slightly immediately after the engine starts (2) 1 start the engine 2- stop the engine after it has run for 1 or 2 minutes 3- Depress the brake pedal by applying normal force 4- the unit is good if the stroke is long the first time the pedal is depressed and becomes shorter as the pedal is depressed repeatedly (as long as rear drum brakes are adjusted properly, to compensate for non-adjusted rears, apply e-brake fully before perfoming this test) Note If the results of this next test are unsatisfactory, check for damage or improper installation of check valve or vacuum lines. If a problem is found make repairs then repeat test. (3) 1-Start engine 2-Depress pedal by applying normal force 3- With pedal depressed, stop the engine 4-Keep pedal depressed for ~ 30 seconds 5-The unit is good if there is no change in pedal height. If it is still pulling to the right, there is something wrong with the left front brake system. If the pedal is rock hard, check for stuck caliper, wheel cylinder or improperly installed pad.

01-22-2010, 10:11 PM	#19
spankle my wankle Rotary Fanatic Join Date: Feb 2008 Posts: 185 Rep Power: 18	thanks ill def give that a try