Hard Pedal, Soft Braking
03-11-2002, 05:15 PM
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Hard Pedal, Soft Braking
Fired up the blue car today to head into work. Heading out of the parking lot the brakes didn't seem to have the quick response I have always counted on, so I tried to lock it up at @ 25mph. It wouldn't, but stopped OK. The car had only been sitting for about 4 days. It should be noted, the pedal was as solid as ever. Braking seemed to improve as I drove, but I didn't have an oportunity to try to lock it up again. I've replaced the front rotors and have flushed the system several times in the last 10K for track use and repair of a leaky sensor. I didn't rebuild the calipers or replace the lines. I'm thinking it may be time. Any thoughts?
JE
928Sx5 <img src="graemlins/c.gif" border="0" alt="[ouch]" />
Drowning in maintenance and restoration
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JE
928Sx5 <img src="graemlins/c.gif" border="0" alt="[ouch]" />
Drowning in maintenance and restoration
<a href="http://members.rennlist.com/jeifert" target="_blank">http://members.rennlist.com/jeifert</a>
03-11-2002, 08:11 PM
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Thanks James.
Well, shoot - it's John Eifert, a Rennlist veteran from way back. Didn't recognize you by your Board handle there John.
I'll give you my best guess on your brake problem, based on my own OB experience. Vacuum leak. Not exactly a new source for our problems. Loss of vacuum makes the brakes feel harder, requiring much more pedal force to activate them effectively.
In your case, check to see that the main hose leading to the brake booster (that big 1" hose) is in good condition. Also, check that the o-ring within that hardpipe off the intake and the associated hose is in good condition (can't recall the name of that assembly).
If it is indeed vacuum related, you may also experience problems with your cruise control, and the climate control system.
Well, shoot - it's John Eifert, a Rennlist veteran from way back. Didn't recognize you by your Board handle there John.
I'll give you my best guess on your brake problem, based on my own OB experience. Vacuum leak. Not exactly a new source for our problems. Loss of vacuum makes the brakes feel harder, requiring much more pedal force to activate them effectively.
In your case, check to see that the main hose leading to the brake booster (that big 1" hose) is in good condition. Also, check that the o-ring within that hardpipe off the intake and the associated hose is in good condition (can't recall the name of that assembly).
If it is indeed vacuum related, you may also experience problems with your cruise control, and the climate control system.
03-13-2002, 10:22 PM
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One test for the vacuum brake booster ...
Witht the engine off, press and release the brake pedal ten times. This ensures that the vacuum reserve is depleted.
Press the brake pedal firmly and hold it down with constant firm pressure.
Start the engine. The pedal should immediately (within a couple of seconds) sink slightly and should then feel slightly softer.
No change in pedal height or feel indicates a problem with the booster or its vacuum supply.
Witht the engine off, press and release the brake pedal ten times. This ensures that the vacuum reserve is depleted.
Press the brake pedal firmly and hold it down with constant firm pressure.
Start the engine. The pedal should immediately (within a couple of seconds) sink slightly and should then feel slightly softer.
No change in pedal height or feel indicates a problem with the booster or its vacuum supply.