I apparently have a vacuum leak because when I put my foot on the brake pedal, whether I'm moving or not, I can hear a hissing noise. When I try to locate it by having someone press on the brake while my head is under the hood, I can't hear it over the engine noise.
Any suggestions?
Assuming it really is a vacuum leak, verified with a vacuum gauge try some starter fluid or carb spray sprayed around the vacuum lines will change the engine RPM when it finds the leak.
Thanks Mike, is there something else I should look for besides vacuum?
John Lynch wrote
This reminds me of a car I had a few years ago. There was a vacuum line under the dash connected to a valve that opened when you pressed on the brake pedal, and you could sometimes hear a hissing noise from that when the brakes were applied. I believe it was used to disengage the cruise control (which was a vacuum controlled system). I can't check my S-10 at the moment to see if it has the same setup, but you might try looking under the dash for something like that.
Thanks, Jon, I don't have cruise control, though.
I had a similar problem like this on a cj7. There was a rushing noise that you could only hear inside the cab. It turned out to be the brake vacuum booster diaphram that had a bad leak where it connected inside the cab to the brake pushrod.
take a look at the check valve on the brake booster. It is a
on the brake
noise. When I try to
head is under the
I had a similar problem like this on a cj7. There was a rushing noise that you could only hear inside the cab. It turned out to be the brake vacuum booster diaphram that had a bad leak where it connected inside the cab to the brake pushrod.
Do you have ABS?
Yes, I do have ABS.
Is the check valve the elbow that the vacuum hose is connected to at the booster tank? Will driving it with a leak make it worse? John
John Lynch wrote:
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