GMCforum
For enthusiast of the Classic GMC Motorhome built from 1973 to 1978. A web-based mirror of the GMCnet mailing list.

Home » Public Forums » GMCnet » [GMCnet] JC4 Vacuum Pump
[GMCnet] JC4 Vacuum Pump [message #326921] Fri, 08 December 2017 17:15 Go to next message
powerjon is currently offline  powerjon   United States
Messages: 2446
Registered: January 2004
Karma: 5
Senior Member
Reformated version hopefully
To All,I have had the Dave L vacuum pump, new booster and pressure
switch control on the pump for almost 2 years now. This setup has
given me a brake system that stops. I have my pressure switch set at
20 InHg as per DL and might go to 22 InHg. The Vac. Pump can handle
that and more. Dave offers a one or 2 port vacuum adapter that goes
between the booster and vacuum pump hose and uses the check valve. The
one shown is a 2 port and I will add a pressure gauge in the future on
the other port.
[1]

This is the Pressure switch that I use and it is available on Ebay.
[6]

I will be interested in the pump that Rob has found on Rockauto. It
appears to be the plastic bodied version of the original pump that was
available a few years ago. I would be interested on the performance of
the pump and seeing its total suck value. Not being at home my test
hence is in the shop. Rob, what is the RA part number?
JR Wright Michigan (On location in Tucson)


Links:
------
[1]
http://www.gmcmhphotos.com/photos/general-pictures/p59295-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59296-dl-brake-layou t.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59297-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59294-dl-brake -layout.html<br
[2]
http://www.gmcmhphotos.com/photos/general-pictures/p59295-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59296-dl-brake-layou t.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59297-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59294-dl-brake -layout.html
[3]
http://www.gmcmhphotos.com/photos/general-pictures/p59295-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59296-dl-brake-layou t.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59297-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59294-dl-brake -layout.html
[4]
http://www.gmcmhphotos.com/photos/general-pictures/p59295-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59296-dl-brake-layou t.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59297-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59294-dl-brake -layout.html
[5]
http://www.gmcmhphotos.com/photos/general-pictures/p59295-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59296-dl-brake-layou t.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59297-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59294-dl-brake -layout.html
[6]
http://www.gmcmhphotos.com/photos/general-pictures/p58771-img-0782.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p58769-img-07811.htmlhttp:// www.gmcmhphotos.com/photos/general-pictures/p58767-img-07801.html<br
[7]
http://www.gmcmhphotos.com/photos/general-pictures/p58771-img-0782.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p58769-img-07811.htmlhttp:// www.gmcmhphotos.com/photos/general-pictures/p58767-img-07801.html
[8]
http://www.gmcmhphotos.com/photos/general-pictures/p58771-img-0782.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p58769-img-07811.htmlhttp:// www.gmcmhphotos.com/photos/general-pictures/p58767-img-07801.html
[9]
http://www.gmcmhphotos.com/photos/general-pictures/p58771-img-0782.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p58769-img-07811.htmlhttp:// www.gmcmhphotos.com/photos/general-pictures/p58767-img-07801.html

_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



J.R. Wright
GMC GreatLaker
GMC Eastern States
GMCMI
78 30' Buskirk Stretch
75 Avion Under Reconstruction
Michigan
Re: [GMCnet] JC4 Vacuum Pump [message #326924 is a reply to message #326921] Fri, 08 December 2017 17:49 Go to previous message
Emery Stora is currently offline  Emery Stora   United States
Messages: 959
Registered: January 2011
Karma: 4
Senior Member
Hi John

Yes, it will go to 22” HG however as your motorhome gets to higher elevations you cannot achieve that amount of vacuum so you’ll have to set the pump lower in order to prevent the pump from running all the time.
I live at 5000 ft now and have it set at 19”HG. If I drive up to 8 or 10000 feet I have to adjust the pressure switch lower.

Emery Stora
77 Kingsley
Frederick, CO

> On Dec 8, 2017, at 4:15 PM, powerjon@chartermi.net wrote:
>
> Reformated version hopefully
> To All,I have had the Dave L vacuum pump, new booster and pressure
> switch control on the pump for almost 2 years now. This setup has
> given me a brake system that stops. I have my pressure switch set at
> 20 InHg as per DL and might go to 22 InHg. The Vac. Pump can handle
> that and more. Dave offers a one or 2 port vacuum adapter that goes
> between the booster and vacuum pump hose and uses the check valve. The
> one shown is a 2 port and I will add a pressure gauge in the future on
> the other port.
> [1]
>
> This is the Pressure switch that I use and it is available on Ebay.
> [6]
>
> I will be interested in the pump that Rob has found on Rockauto. It
> appears to be the plastic bodied version of the original pump that was
> available a few years ago. I would be interested on the performance of
> the pump and seeing its total suck value. Not being at home my test
> hence is in the shop. Rob, what is the RA part number?
> JR Wright Michigan (On location in Tucson)
>
>
> Links:
> ------
> [1]
> http://www.gmcmhphotos.com/photos/general-pictures/p59295-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59296-dl-brake-layou t.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59297-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59294-dl-brake -layout.html<br
> [2]
> http://www.gmcmhphotos.com/photos/general-pictures/p59295-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59296-dl-brake-layou t.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59297-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59294-dl-brake -layout.html
> [3]
> http://www.gmcmhphotos.com/photos/general-pictures/p59295-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59296-dl-brake-layou t.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59297-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59294-dl-brake -layout.html
> [4]
> http://www.gmcmhphotos.com/photos/general-pictures/p59295-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59296-dl-brake-layou t.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59297-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59294-dl-brake -layout.html
> [5]
> http://www.gmcmhphotos.com/photos/general-pictures/p59295-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59296-dl-brake-layou t.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59297-dl-brake-layout.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p59294-dl-brake -layout.html
> [6]
> http://www.gmcmhphotos.com/photos/general-pictures/p58771-img-0782.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p58769-img-07811.htmlhttp:// www.gmcmhphotos.com/photos/general-pictures/p58767-img-07801.html<br
> [7]
> http://www.gmcmhphotos.com/photos/general-pictures/p58771-img-0782.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p58769-img-07811.htmlhttp:// www.gmcmhphotos.com/photos/general-pictures/p58767-img-07801.html
> [8]
> http://www.gmcmhphotos.com/photos/general-pictures/p58771-img-0782.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p58769-img-07811.htmlhttp:// www.gmcmhphotos.com/photos/general-pictures/p58767-img-07801.html
> [9]
> http://www.gmcmhphotos.com/photos/general-pictures/p58771-img-0782.htmlhttp://www.gmcmhphotos.com/photos/general-pictures/p58769-img-07811.htmlhttp:// www.gmcmhphotos.com/photos/general-pictures/p58767-img-07801.html
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org


_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Previous Topic: Why Did I Order This?
Next Topic: [GMCnet] 455 Right side (passenger ) Exhaust Manifold
Goto Forum:
  


Current Time: Fri Mar 29 06:22:53 CDT 2024

Total time taken to generate the page: 0.01026 seconds