| Vacuum pump problem/question [message #203514] |
Wed, 03 April 2013 11:30  |
kerry pinkerton
Messages: 2565
Registered: July 2012
Location: Harvest, Al
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Paul and Nancy Doane visited last night and he drove my coach. I started asking some questions about vacuum and he noticed that while my coach ran great, the vacuum guage read a bit higher than his did. This morning before they left we did some poking and Paul noticed that when the vacuum pump came on, it blew back through the manifold and up through the carb. We pulled the booster vacuum line and sure enough when you press the brake pedal to trigger the pump, it blows back through the manifold vacuum line.
My vacuum pump, installed by my beloved PO is not the typical JC4. I don't know what it is. However, it has an input (suction) and an output (exhaust). The suction line from the pump went to the booster and did indeed suck. The manifold vacuum was hooked to the exhaust port of the pump through a check valve. I see no other ports on the vacuum pump. The pump has to have a supply source but somehow I'm thinking it should not end up pushing air into the manifold.
So what is going on here? Is the check valve on the manifold vacuum line bad or backward? It's got to exhaust somewhere. What is the normal hook up for the manifold vacuum and a single booster port?
On my new sensitized booster, I had an extra vacuum port installed so I can hook manifold vacuum to one port and the pump vacuum line to the other (with check valves). No problem there but I guess I need a screen or something to keep critters from nesting in the pump.
And what vehicles have the JC4 vacuum pumps? And where are they typically located?
Kerry Pinkerton - North Alabama
Had 5 over the years. Currently have a '06 Fleetwood Discovery 39L
[Updated on: Wed, 03 April 2013 11:59] Report message to a moderator |
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