1951 200 Part Interchangeability

Discussions related to interchangeability between years and models, and currently available modern sources for parts.
Westside '51 200
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Location: Venice, CA

Re: 1951 200 Part Interchangeability

Post by Westside '51 200 » Thu Jan 17, 2019 10:07 pm

Thanks Howard! I've read several accounts that state adding the booster isn't really worth it and that the difference doesn't make it worth it. Do you have an opinion or have you heard the same from sources you trust?

Westside '51 200
Posts: 9
Joined: Fri Jan 11, 2019 9:04 am
Location: Venice, CA

Re: 1951 200 Part Interchangeability

Post by Westside '51 200 » Fri Jan 18, 2019 12:13 am

I'm having a challenge with the bolt patter -is this a 5x5 on the 1951 Junior?

Dave Czirr
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Re: 1951 200 Part Interchangeability

Post by Dave Czirr » Fri Jan 18, 2019 6:12 am

The Bendix power brake booster, a/k/a the TreadleVac, was the standard of the era, used by Packard, Buick, Cadillac, Hudson, Nash, Lincoln, Pontiac, and others including Mercedes Benz. It's a very effective and, properly rebuilt and maintained, reliable unit.

Howard56
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Re: 1951 200 Part Interchangeability

Post by Howard56 » Fri Jan 18, 2019 7:17 am

There is a definite change in braking characteristics with power brakes. The manual brake is quite adequate but there is the typical lifting of the foot to exert pressure and the long pedal travel before the car stops. The power system requires just shifting the toe from the accelerator pedal over to the brake pedal and giving a slight push -- usually if the brakes are adjusted properly maybe 1/2 - 1 inch max travel before your face wants to meet the windshield.

I won't get into the arguments of the Treadlevac unit itself over here. Packard people usually refer to it as a BTV and you can find plenty of those discussions at packardinfo if you do a search for BTV threads. There are horror stories about sudden failures and equal reports of units giving a long trouble free life. I can't prove it but one perception I have with the various sudden fail stories seem to be more on the V8 cars. Whether that is due to those cars being driven more or to the fact the BTV unit is fairly close to an exhaust manifold and gets more heat than the earlier cars is a question. One thing that does seem to be common is failure reports come from cars that have suddenly been placed into operation after having sat for a long time.

As with anything, maintenance of the BTV is critical. A periodic fluid change is recommended and there are some inner pieces that need to be in top condition. Some of the critical internal items are the main seal around the ram, the rubber seal on the compensator valve, and an unobstructed relief port passage. Failure in those parts will result in sudden no brakes and contributions to the stories of stopping at one light and sailing thru the next. The main seal can dry or crack and start leaking if the car or unit has been sitting for lots of years without fluid. If the relief port is blocked because of the lid gasket, with a leaking main seal the vacuum side can suck the fluid out of the hydraulic side and into the power chamber. Solidified crud in the old fluid can float around and lodge under the compensator valve keeping it from closing tightly letting the fluid leak back into the reservoir instead of going to the wheels.

As you said your BTV came uninstalled along with the car, even if it is NOS or an unused rebuild if it is old and you do not know the history it would be to your benefit to have it gone thru and make sure everything is still in good shape.

Westside '51 200
Posts: 9
Joined: Fri Jan 11, 2019 9:04 am
Location: Venice, CA

Re: 1951 200 Part Interchangeability

Post by Westside '51 200 » Fri Jan 18, 2019 12:13 pm

Thanks Gents!

I've searched around and I've read that the the bolt patter (wheels) is 5" with 5 lugs or some being 4.5 with 5 lugs. Is this variation true and if so what determined 5" vs 4.5" lugs?

Howard56
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Re: 1951 200 Part Interchangeability

Post by Howard56 » Fri Jan 18, 2019 12:52 pm

Junior vs senior car determines the wheel size. Almost all the suspension and drive components are larger on a senior car so your junior 200 will have the smaller size. For the life of me I can't remember the bolt pattern but 5 for juniors seems right. Believe most of the seniors are 5 1/2 but someone else will have to confirm that.

Another obstacle to quickly finding a workable wheel is the diameter of the center hole is comparatively large on Packard wheels. That year Packard also used lug bolts to hold the wheel instead of studs and nuts so the wheel needs to have the extra clearance holes to provide someplace for the locating pin riveted to the drum to pass thru. The pins have been cut off to allow other wheels to work but they do serve a purpose so best to find the correct wheel. Because of the center hole and clearance hole requirements it will limit the interchange between other brand cars.

I believe a few possible interchanges were discussed at packardinfo some years ago. A search may find those discussions but perhaps someone posting here will have an answer to the question first.

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Tinman_70
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Re: 1951 200 Part Interchangeability

Post by Tinman_70 » Sat Jan 19, 2019 6:49 am

Are the 5 X 5 wheels from the Series 22/23 the same as the '51-'54? I have a set of 4 that I plan on putting on ebay and would like to state all the Packards they will fit.
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Dave Czirr
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Re: 1951 200 Part Interchangeability

Post by Dave Czirr » Sat Jan 19, 2019 7:09 am

Hope this helps, sorry that I couldn't get a full legible scan including the part numbers. But as you can see there are about 24 different wheels used between the 22nd series and the 54th, each line item is a unique different part number. And on quick look I only saw one that had coverage from the 22nd Series into the 51-54 model years.
Attachments
Wheels 48 thru 54.jpg

Westside '51 200
Posts: 9
Joined: Fri Jan 11, 2019 9:04 am
Location: Venice, CA

Re: 1951 200 Part Interchangeability

Post by Westside '51 200 » Mon Apr 22, 2019 8:20 pm

Hello again - I wanted to circle back so others don’t repeat my Mistake

After ordering and powered coating wheels I realized the bolt pattern is 5x4.75 :shock:

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