Brakes Brakes: Hard/Short Then Long/Squishy/Soft Underfoot

• Inspected rear slave cylinders for leaks
• Flushed brake fluid
• Repeatedly bled all four brakes
• Replaced the Master Cylinder
• Bench bled the Master Cylinder
• Replaced the rubber flex lines with Aeroquip performance hose lines

90sickfox said:

Sticky wheel cylinders will do that on stock brakes. When they don't move correctly at both ends it'll make the pedal feel harder.

I think everyone should have a temperature gun. It's one of the best tools for diagnosing brake issues. You want one that goes up to at least 900 degrees so you can check exhaust manifold tubes for proper combustion burn ( that's a whole different subject ).

The rear drums should be the same temp side to side...so should the front rotors. Sticking calipers, brake pads, caliper pins, and collapsed hoses usually cause a higher temperature on that wheel. Incorrectly adjusted rear brakes, sticking wheel cylinders, and sticking brake shoes usually cause low temperature readings.

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1. Bring brakes up to temperature with a half dozen emergency stops from 30 mph.
2. Hope that the alternating hard/soft pedal phenomenon occurs
3. Upon the final emergency stop, pull over to the side of the road and take infrared temperature readings at each wheel
4. Disassemble the low temperature rear wheel brake and dissassemble the high temp front corner. Polish & grease sliding surfaces. Reassemble. Retest

90sickfox said:

Yes, almost exactly like that. The best way is to get them hot by driving like you normally would. Slow moderate brake pressure will show signs easier than stabbing the brakes. Pushing the brakes hard can apply enough pressure to make a sticking cylinder push out both sides...negating the test.

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