Packard Forum Index » Post-War (1946-54)

Packards and lesser vehivles are logical beings, treat them as such and they will give a liftime of pleasure. Except of course '56 with pushbuttons

Fred, I put clothes pins on my pushbuttons, the relays and the actuator motor, and haven't had a problem since. Don't knock it, I'm just following (actually, extending) your advice.

Quote:

Did you read my last post?? 7/8" is not enough. No wonder you loose water. You might as well leave the cap off. I just measured the drop on my radiator and it is 1". You need to find the correct cap. Your cap is 1/8" short. No Seal. I told you My car had the same problem when I got it (WRONG CAP).

Quote:

I would not. The system was designed for a 7 lb. cap and that's what should be on there. Increasing the pressure will only increase the possibility of blowing something out.


Again, Just try the correct cap. 7 lb. with a 1 inch drop.

The The parts dealer here where I bought my cap did not have the cap listed for Packard per say. He just went through his books and found a 7 lb. cap with the proper drop. Wish I could remember the number on it. I would give it to you.

+1 on the radiator cap, had the same issue. Use the right cap. If you can't find one, lookup a local radiator shop. Might even just give you one if you stop by with the car and tell him you can't find the right cap. Those guys know every detail about radiators we'd never care to get into.

thanks - going to O'Riley's in the morning for a Murry 7007. If that doesn't work, off to the radiator shop.

Just to cut to the chase, how about you guys post the model numbers on the CAPs that work and that should simplify the search for others. I believe all 51-54 radiators use the same style cap.

I'm showing the following caps to be correct. Someone correct me if I am wrong:

Napa 703-1411 - 7lb Cap

or

AC RC-7

The Packard p/n for the 7lb cap is 446222. This p/n applies to all 22nd, 23rd, 24th, 25th, 26th and 54th series cars.

The NAPA (Balkamp) equivalent cap p/n (7 lbs, 1 13/32 inch height) is 703-1411.

Kev... you are correct.

Re the 7# radiator cap and going to a higher one. Packard in 53 did change to a 12# on seniors (part 377264) and then across the line later in the year and made that change retroactive back to 51 on cars where there had been repeated episodes of coolant loss.https://www.packardinfo.com/xoops/html/downloads/SC/SC-VOL27NO2.pdf If you can find a 12 with one inch drop, that would be a proper option if the 7 still has a problem and everything else is in good shape.

Looks like they finally settled on a 13 lb cap after all the dust settled. The 7lb works well on my bathtubs... no problem with overflow.

Attach file:

---

  (21.28 KB)

I sure stirred up a hornet's nest here. I went to NAPA and picked up a 703-1411, 7 lb cap. It has the 1" drop and worked fine - Cost $5.77. Took the Packard out this afternoon up a 13% grade, the gauge went up to the "P" in temp, and then back down as soon as I was on top of the hill. Made about a 15 mile trip, which previously would end in boiling over. No problems today. However, I also added a bottle of "water wetter" which is supposed to make the water more able to transfer heat. I should have done one at a time, but so far I'm happy. No more boiling over. thanks to all.