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ss396t6
02-14-2015, 10:37 PM
When the '55-'57 Thunderbirds were new what radiator cap came on the radiator? PSI?

Thanks,
Scott

YellowRose
02-14-2015, 11:02 PM
Hi Scott! I hope you are still not having radiator problems with that new one. According to the CASCO website, '55-'57's use a 7lb radiator cap, cost, $10.90, Part # 8100B.

http://www.parts123.com/parts123/yb.dll?parta~dyndetail~Z5Z5Z50000219a~Z5Z5Z5AAFMS~ P10.90~~~~S4A61AXPO270239119524o~Z5Z5Z5~Z5Z5Z50000 219a#

ss396t6
02-15-2015, 10:40 AM
No, the radiator is performing great. I am asking about original issue radiator caps from a correctness standpoint.

I believe the original radiator caps were stamped S. M. CO. with a patent number around a large domed rivet. One ear might have R-7 and large, raised words on the perimeter were TIGHTEN and REMOVE SLOWLY with arrows. However, I am not certain of this as so many reproducers have several caps they claim as "exact reproduction" which usually aren't.

Thanks

YellowRose
02-15-2015, 11:16 AM
Try contacting some of the NOS and Obsolete Parts places listed in the Advertisements Forum, or Stan Levy to see what he has. The part # is probably B7-8100-B or maybe B5-8100-B, or B6-8100-B. They should all be the same. There could also be an A after the number instead of the B.

jopizz
02-15-2015, 11:26 AM
Tee-Bird products shows that they have an exact reproduction 55-57 Thunderbird cap but it says 13 lbs.

http://www.tee-bird.com/catalog_product_detailed.cfm?id=12670

John

Joe Johnston
02-15-2015, 12:02 PM
I have the 56 Shop manual handy and it states:

"The cooling system of the passenger car is pressurized at approximately 13 psi."

on page 115. Subsequent pages make no mention of a cap for Thunderbirds.

Page 363 in the spec section states:

"Cooling system on all cars is pressurized to 12-15 pounds."

This section does give Thunderbird specific specs, but no mention of a different rating for the cap on a Thunderbird, but I will check other sources.

YellowRose
02-15-2015, 01:13 PM
Apparently, CASCO, a major supplier of parts for Babybirds, does not have it correct then. Their ad shows it is a 7lb cap....

Joe Johnston
02-15-2015, 02:17 PM
Apparently, CASCO, a major supplier of parts for Babybirds, does not have it correct then. Their ad shows it is a 7lb cap..

Perhaps...............but it may depend on their reference source.

page 23 of the Compilation of Product Service Letters dated 12/29/1954 states the cap is to be of the 12 - 15 lb variety instead of the 7 lb rating used for 1954 products. Also is a footnote to revise the 55 Ford car Shop Manual (page 338 secton 8) to read "Cooling system is pressurized to 12-15 pounds on all cars and Thunderbirds." The 55 Shop Manual (which I don't have) should state 7 lb cap originally - so that may be the source of confusion.

jopizz
02-15-2015, 02:45 PM
Here's what the Master Parts Catalog shows. It looks like 1954 was the last year a 7 lb cap was used.

John

YellowRose
02-15-2015, 03:16 PM
I have just brought this to CASCO's attention with an email and pointed to the comments here on the Forum regarding this. As jopizz points out, and the other posts do, the last year for a 7lb radiator cap on a Ford product was on the years prior to 1955.

YellowRose
02-16-2015, 12:00 PM
CASCO has responded and said he would bring this information to the attention of their inventory administrator.

When I searched their parts123 website for radiator cap, only the 7lb cap came up for me, for some reason. When I searched it with the 8100 part #, all three caps came up.

I just talked with them and they tell me that they have 3 radiator caps available. The 8100 13lb cap for $9.99 which is just a plain replacement cap. The 8100A which is an original looking 13lb cap for $31.40 for those who want the original cap. The 8100B, which is a 7lb replacement cap for $10.90, for those who need that cap.

So there ya go. Scott, from what they tell me, the 8100A is a reproduction of the original looking cap. If you are looking for an original cap, try looking for the B8A-8100-A by calling those NOS, NOS Parts, Obsolete Parts, etc.. companies listed in the Advertisements forum. Check with Stan Levy, as he might have an original one on one of his parts Babybirds. You might get lucky. Let me know if you find one.

ss396t6
02-16-2015, 02:57 PM
Thanks, all. Concoursparts.com states that their 8100-R is the exact reproduction of the original. And there is even a photo of it.

YellowRose
02-16-2015, 03:05 PM
Great! I did not look at the other sites. Looks like ya found something that will work and it is a bit cheaper!

YellowRose
02-16-2015, 06:15 PM
In doing some calling around to the NOS and Obsolete places in our Ad Forum, I found this out, and told Scott. The B8A-8100-A is a 13lb zinc radiator cap. The one that I did find is not a NOS unit, but a Repro. There is a C1UU-8100-A which is a 13lb Lever Pressure Release radiator cap and a Chrome version, the C2SZ-8100-A (if you can find one without it costing you an arm and a leg). So there ya go, you other Littlebird owners, in case you ever have to look for one.

paul274854
02-17-2015, 10:04 PM
Originally the early birds came with a 13 lb cap. Because of aging original radiators, a 7 lb cap is recommended. If you have a new or recored radiator, the 13 lb one should be ok.

ss396t6
02-21-2015, 10:03 AM
In doing some calling around to the NOS and Obsolete places in our Ad Forum, I found this out, and told Scott. The B8A-8100-A is a 13lb zinc radiator cap. The one that I did find is not a NOS unit, but a Repro. There is a C1UU-8100-A which is a 13lb Lever Pressure Release radiator cap and a Chrome version, the C2SZ-8100-A (if you can find one without it costing you an arm and a leg). So there ya go, you other Littlebird owners, in case you ever have to look for one.

The one problem with the lever release cap is that if one forgets to push the lever down and closes the hood there is going to be a "nice" little uh-oh in the front of the hood.