loss of brake pressure - cruise control

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loss of brake pressure - cruise control

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loss of brake pressure - cruise control - 8/28/2008 9:14:24 AM

cycleboy

Posts: 131
Joined: 1/21/2008
Status: online

I had something interesting happen to me this morning and I can''''t quite explain it. I had a 20 minute or so highway drive returning from court in an adjacent county. I got into town and drove all the way through with no problems. As I neared my destination, I lost a significant portion of my brake pressure and as I sat at a light I could feel the pedal going down to the floor.

I reached my destination, went in, came back out 15 minutes later, and checked out the car. The master cylinder was full, there was no evidence of leakage at any of the calipers or lines and all the vacuum lines were connected. I started the car and heard a horrible racket coming from the cruise control motor (which has never worked previously) and so I disconnected its connection. But, to the best of my knowledge there is simply no way the cruise control can have an effect on the brakes, which are an isolated and closed hydro-mechanical system. I got in the car to test the brakes and they worked just fine. I drove home (about 3.5 miles of stop and go) with no further problems.

I''''m at a complete loss to explain this unless of course I have a caliper sticking and the overheating caused some fade. I just don''''t know.

Has anybody else experienced anything similar?

Car is an ''''82 300CD.

< Message edited by cycleboy -- 8/28/2008 9:23:13 AM >

Post #: 1

RE: loss of brake pressure - cruise control - 8/30/2008 12:06:36 AM

ForcedInduction

Posts: 844
Joined: 5/20/2006
From: Federal Heights, Colorado
Status: online

Check your brake hoses for soft spots, cracks and bubbles. Thats about the only thing I can think of that might cause it unless the master cylinder is failing.

_____________________________

1980 240D 3.0VNT 222K Miles. OM617.95, GT2256V VNT turbo, 4-speed manual, 3.46 diff, 15mm rear swaybar, ALDA removed, no EGR and Amsoil by-pass oil filter. Currently 107HP and 195lb/ft of torque at the wheels.

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(in reply to cycleboy)

Post #: 2

RE: loss of brake pressure - cruise control - 8/30/2008 8:37:48 AM

cycleboy

Posts: 131
Joined: 1/21/2008
Status: online

To top it off, I drove to Chicago and back Thurs/Fri (150 miles each way) with no recurrence. This is rather odd in my opinion. The only thing I can think of is perhaps a piece of debris loose in the master cylinder that would have prevented intake of fluid at one point when the pedal was released, but even still that should only have affected two of the wheels and wouldn''t totally account for the radical pedal drop.

(in reply to ForcedInduction)

Post #: 3