Brake pedal goes half-way to the floor, only the first time.
Finally driving my car again after it was laid up for 2 months.
I don't think it was like this 3 months ago.
When I first press the brake pedal, it goes half-way, but certainly not
all the way, to the floor, and at t hat point it stops the car very
well. If I press the pedal again within 2 or 3 minutes, it moves very
little before it's stopping the car.
If I wait maybe 15?? minutes, it's like the first sentence in the
What's the problem?
Bad master cylinder?
If you disconnected the caliper while you were working on the front end
the system probably needs bleeding - even if you didn't it probably does .
Some cars require bleeding both front and rear systems to maintain balance
in the valving system . Your repair manual should have the procedure .
No, I didn't. (For others planning to do this: At first I did what I
usually do, I hung the caliper from other parts using a bent wire
hanger, but later I had a loop of fairly heavy stranded electrical wire
and that worked better.)
Is the symptom I have really caused by needing bleeding? I had spongy
brakes once after doing something to the brakes, and every time I pushed
the pedal it was the same, spongy, like stepping on a sponge. Now
it's never spongy. When the pedal is going down the first time, there
is almost no resistance (only what comes from the spring) until there is
I'm foggy, but I think it could be a brake opening up mechanically, more
than normal, as you drive, gradually pushing fluid back into the master
If you have drums in the rear, one or both may need adjustment.
Sometimes pulling up the slack with the parking brake will act as a
temporary adjustment. If a rotor is warped, it could move the caliper
back and forth as you drive, gradually opening it.
Is this the same car you did the suspension work on? If so you may have
introduced air into the system through cracks in the hose or bulging.
The first step is to top off the master cylinder then bleed the brakes
properly, per manufacturers instructions. If that doesn't work it is
probably the master cylinder, diagnose and repair per manufacturers
instructions. If it has power brakes it may be the booster but IDK your set
up. I have a faulty memory on this subject.
I've had that happen with a couple of vehicles after I changed the
brake shoes or pads and didn't bleed their cylinders. Bleeding
always stopped the pedal from sinking.
After I bleed brakes, I close all the bleeder screws and pump the
pedal hard a few times. Then I open each screw, and usually no
fluid comes out right away, indicating there was still some air
Have four-wheel disks taken over? Well call me Rip Van Winkle! How do
you guys go parking without rolling into the lake?
The 1949 Chrysler Crown Imperial had four-wheel disks, but owners hated
them. The 1950 Crosley Hot Shot had them. Owners paid to have them
changed to drums.
The 1962 Studebaker Avanti established the standard of disks on the
front and drums on the rear.
If Micky has no drums, I believe brake mechanics could still be the
problem. Typically, runout is specified at less than .05mm.
If it's greater, and the cause is uneven transfer from the pads,
resulting in uneven disk thickness, the driver will feel pedal pulsing.
If that's not the case, and the measurement varies once per revolution,
the problem could be contamination between the disk and the hub face.
Otherwise, it could be a warped disk, which can happen putting lug nuts
If a disk wiggles ever so slightly as the car runs down the road, the
caliper will wiggle. I can't speak from experience, but I imagine this
wiggling could open the caliper ever so slightly, causing a long push
the first time the brake pedal is pushed.
What kind of vehicle are we talking about? Was it ever stated?
Both of my cars still have drum rear brakes, with self adjusters which
by their very design have a tendancy to fail to adjust the brakes -
particularly on cars with automatic transmissions where the driver
seldom if ever uses the parking brake - which adjusts the brakes when
it is applied.
On 10/31/14, 9:18 PM, firstname.lastname@example.org wrote:
I wondered, too. Found it (September 30):
"I hit a curb with my car and broke in half the right half-axle, broke a
big chunk out of the RF rim and a piece the size of a tea-cup saucer
from the tire too, cracked my lower suspension arm, and severed the
right ball joint (2000 Toyota Solara, only has a lower ball joint. I'm
not sure how many cars this story covers. "
That car seems to have disks all around. After gazing into my crystal
ball, I'll vote for runout. It could come from damage to the disk or
hub, or it could be a little rust from all the time it sat disassembled.
It may take thousands of miles of wear before the pedal starts to pulse.
Micky may have caught it quickly enough to fix it without buying
parts... if it's rust or dirt.
On 11/1/14, 11:32 AM, email@example.com wrote:
I've been too optimistic. How could the hub transmit enough force to
break an axle, crack a suspension arm, and sever a ball joint, without
being damaged? Hub runout should show that a new hub and bearing is
needed. An optimist could hope the disk is OK.
Given the recent history of the vehicle -IE- it's damage history, I'd
be looking at the brake on the damaged axle first. Clamp off the brake
flex hose to that wheel. Is the pedal highand firm? If not, look
elsewhere. If so, you know where to look. Brake hose clamps are
available at Harbor frioeght and many auto parts/tool suppliers at
reasonable cost. Some are little screw clamps, others are a vice-grips
with round rod jaws. Make your own by brazing a 1/4 inch long 1/4 or
5/16" diameter steerl rods to a 6 or 8 inch cheap vice grips.