Author Topic: Normal operation or a lurking problem?  (Read 86 times)

Offline fiddler

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Normal operation or a lurking problem?
« on: August 10, 2017, 08:38:30 PM »
I have a 1974 Chevy C10 step side.  350 automatic with vacuum power assist brakes.  I recently cleaned up all of the old vacuum lines.  The line to the brakes was deteriorated by the carburetor to the point that it was leaking through the walls of the hose.  So it was pulling some vacuum but wasn't right.  Now I have corrected that problem, and I have the truck purring like a cheetah, but when I step on the brakes at idle, I notice the idle speed increases.  Is this normal operation?  Is it impending doom?  Has anybody noticed this before on their truck??  Maybe I need to readjust something?

Thanks for any inputs,

ricky
Ricky

Offline bd

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Re: Normal operation or a lurking problem?
« Reply #1 on: August 10, 2017, 08:41:52 PM »
First, make sure that the power brake booster vacuum hose is 11/32", textile reinforced, stiff-wall EPDM rubber hose that meets SAE J1403 Type L and DOT FMVSS 106 requirements.

Second, replace the power brake vacuum booster.
Rich
It's difficult to know just how much you don't know, until you know it....
In other words... if people learn by making mistakes, by now I should know just about everything!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline fiddler

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Re: Normal operation or a lurking problem?
« Reply #2 on: August 10, 2017, 10:58:00 PM »
Thanks much.  I will verify the hose with the NAPA guy tomorrow.  The hose I used is a multipurpose from NAPA and is supposed to be suitable for this application but I will verify before I change the out the vacuum booster. 

ricky
Ricky