Author Topic: Coolant coming out of overflow  (Read 4496 times)

lcmc

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Coolant coming out of overflow
« on: June 07, 2007, 03:48:55 AM »
My car doesn't over heat but I keep losing coolant from the overflow. Radiator is only filled to full mark so it is not over full. Where should I start to solve this problem?
Danny
1969 Z/28 X77
1970 Nova L78 9300 original miles

rich69rs

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Re: Coolant coming out of overflow
« Reply #1 on: June 07, 2007, 04:31:49 AM »
Sounds like maybe your radiator cap is opening at too low a pressure.  If it is operating properly, the radiator cap should not open to the overflow unless the pressure exceeds 15 psi. 

I would start by having your radiator cap checked to be sure it is still holding rated pressure (15 psi) without leaking down.  If you don't have the tester in your tool box to do this, any radiator shop can do this for you.  Just takes a couple of minutes.  All you have to do is bring the radiator cap to the shop for the test.

Had a similar problem on my ride a couple years ago - new radiator cap and all was well.
« Last Edit: June 07, 2007, 04:40:18 AM by rich69rs »
Richard Thomas
1969 RS

lcmc

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Re: Coolant coming out of overflow
« Reply #2 on: June 07, 2007, 05:16:47 AM »
I'll have it checked out and keep ya posted........thanks
Danny
1969 Z/28 X77
1970 Nova L78 9300 original miles

lcmc

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Re: Coolant coming out of overflow
« Reply #3 on: June 08, 2007, 02:02:44 AM »
Had the cap checked today and it only held 3 lbs. Looks like that is the problem. Parts store didn't have a new one so I'll try to get one tomorrow and try that. If that works then I need to find a NOS cap since my car is a survivor.
Danny
1969 Z/28 X77
1970 Nova L78 9300 original miles

rich69rs

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Re: Coolant coming out of overflow
« Reply #4 on: June 08, 2007, 02:14:16 AM »
Glad to hear that it looks like you've isolated the problem.  Watched a NOS cap the other day on eBay go for $77.

Good luck.

Richard
Richard Thomas
1969 RS

lcmc

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Re: Coolant coming out of overflow
« Reply #5 on: June 08, 2007, 05:02:09 AM »
Richard.....I believe the cap I have now is the original to the car. It reads "TURN TIGHT" and "REMOVE SLOWLY". I've seen caps on ebay selling as NOS that read "NEVER OPEN HOT" and "INSPECT FALL & SPRING". Which is the correct cap?
Danny
1969 Z/28 X77
1970 Nova L78 9300 original miles

JohnZ

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Re: Coolant coming out of overflow
« Reply #6 on: June 08, 2007, 01:54:39 PM »
Here's a photo of the original RC-15 cap on my '69 Z/28.
'69 Z/28
Fathom Green
CRG

lcmc

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Re: Coolant coming out of overflow
« Reply #7 on: June 08, 2007, 02:35:41 PM »
JohnZ....that's the cap on my car now. I thought it was original. The ones on ebay and are different that say NOS must be OEM replacement caps. If anyone knows where I can get the correct cap let me know.
Danny
1969 Z/28 X77
1970 Nova L78 9300 original miles

Gramps69Z

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Re: Coolant coming out of overflow
« Reply #8 on: June 08, 2007, 04:16:28 PM »
I got mine from NPD, $24.95 with correct marking.
Captain John Wykoff
Destin Fire     5 months  to go

I'm sick and tired of mismanagement and disappointment. 
I'm a COWBOYS fan.

rich69rs

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Re: Coolant coming out of overflow
« Reply #9 on: June 08, 2007, 04:22:59 PM »
They are available in the aftermarket.  The attached PDF file is the one I purchased from Year One, also with the correct makring.
Richard Thomas
1969 RS

lcmc

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Re: Coolant coming out of overflow
« Reply #10 on: June 08, 2007, 05:43:31 PM »
Thanks guys....I bought a cheapy today just to make sure that solves my problem. Once I make sure it does I'll probably go with the reproduction until I find the correct NOS.
Danny
1969 Z/28 X77
1970 Nova L78 9300 original miles

lcmc

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Re: Coolant coming out of overflow
« Reply #11 on: June 08, 2007, 06:19:34 PM »
Problem solved.....just took a test drive. No more overflow!
Danny
1969 Z/28 X77
1970 Nova L78 9300 original miles

169INDY

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Re: Coolant coming out of overflow
« Reply #12 on: June 09, 2007, 04:21:17 AM »
Just for additional information. If you a lucky enough to have your orig RC15 on your car but it has seemed to aged to much you can get them restored by John Prikle. He rebuilt mine on the pace car and it looks awesome! The plating, new gasketing and Orig stlye rivet completed the package. Off the top of my head I can not remember how much it cost but it was worth it.

Jim ;D
Jim
68 SS/RS L35 Th-400 LOS
69 Pace Car L48 Th-350 LOS

lcmc

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Re: Coolant coming out of overflow
« Reply #13 on: June 09, 2007, 04:09:18 PM »
Jim......I do have the original. I would not want mine restored since my car is a survivor, however I was wondering if you could just have them rebuilt. Do you have contact info for for this guy?
Danny
1969 Z/28 X77
1970 Nova L78 9300 original miles

Gramps69Z

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Re: Coolant coming out of overflow
« Reply #14 on: June 09, 2007, 04:40:50 PM »
Contact information : www.johnpirkle.com    (706)860-9047
He also sells and restores other parts.   I hope he can help you.  8)
Captain John Wykoff
Destin Fire     5 months  to go

I'm sick and tired of mismanagement and disappointment. 
I'm a COWBOYS fan.