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 » Freeze Plugs- what do i need to know ?
Re: [GMCnet] Freeze Plugs- what do i need to know ? [message #351693 is a reply to message #351456] Mon, 20 January 2020 12:09 Go to previous messageGo to previous message
Emery Stora is currently offline  Emery Stora   United States
Messages: 959
Registered: January 2011
Karma:
Senior Member
Don’t put shop compressed air to your radiator. You could easily blow it out.
If you have an original radiator you could regulate it to perhaps 15 psi and it should work.
However you are much better off using a Stant radiator pressure tester such as
https://www.amazon.com/Stant-12270-Cooling-System-Pressure/dp/B0002SRGWU/ref=asc_df_B0002SRGWU/?tag=hyprod-20&linkCode=df0&hvadid=312844081654 &hvpos=1o1&hvnetw=g&hvrand=2778592311742544424&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=902 8887&hvtargid=pla-569917460079&psc=1

This has a gauge and arrows showing your pressure as you pump it.

I have one that is about 45 years old and it is still working well. It can be used to test pressure caps as well.
I often bring it to rallies to test other peoples systems.

I was at one rally a few years back and about 20 people wanted me to test their radiators for leaks.
I told them I would also test their caps and said I would wager that about 70% of the caps would not hold pressure.
I was wrong. About 85% of their caps were bad. I told them that a pressure cap has a spring that is constantly working and it gets weak.
It also has a rubber gasket that deteriorates over time. The average radiator cap will only last about 2 years.

If you have an original GMC radiator you should not use more than a 9# cap. If you have an aluminum radiator you can use about a 15# cap.
The higher pressure caps will put pressure on the system and increase the boiling point.

Emery Stora
77 Kingsley
Frederick, CO

> On Jan 20, 2020, at 10:47 AM, dave silva via Gmclist wrote:
>
> Thanks Matt,
>
> Cooling system pressure test ?
>
> What would be a good target PSI? Would it be as simple as putting shop air to a heater hose?
>
>
> --
> Dave & Ellen Silva
>
> 1972 Revcon Olds 455, toro drive train. All Stock
>
>
>
> _______________________________________________
> 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

Report message to a moderator

[Message index]
 
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Read Message
Previous Topic: [GMCnet] Air cleaner clearance. More then one way to skin a cat
Next Topic: [GMCnet] RAMCO Mirror dual switch wiring diagram
Goto Forum:
  


Current Time: Mon Sep 23 04:54:42 CDT 2024

Total time taken to generate the page: 0.01295 seconds
.:: Contact :: Home ::.

Powered by: FUDforum 3.1.1.
Copyright ©2001-2021 FUDforum Bulletin Board Software