Packard Forum Index » V-8 (1955-56)

Turbopacman wrote: Quote:

Come on, Eric! We need that video documentation to clarify things for unread, semi-informed people such as 55PackardGuy.

Craig

It'll have to be next weekend, rain today through most of this coming week.

G'day Mates,

I somewhat reluctantly join this discussion because of a) my inadequate knowledge of power boosters, b) because earlier this year I installed a BTV that had just been rebuilt by Karps of CA and c) the obviously strong views for and against BTV's. I opted to stick with the BTV because the previous one had lasted for 27 years and even then, only the boost function had failed. That is, the brakes would work but took plenty of leg power to operate, more than I had to spare.

I have a '56 Patrician with push button auto and had just replaced the front wheel bearings, had the wheel cylinders re-sleeved and after bleeding the brakes, found I had no boost. My assumption was that perhaps the pumping for the bleeding had interfered somehow with the boost side of things. The replacement BTV was subsequently fitted, filled with Dot 4 low moisture absorbent fluid and has been driven for about 2,500 miles and given no major braking problems. The only issue I'm aware of, and it's certainly an annoyance, is that the level of boost is too low meaning required pedal pressure is too high, although nowhere near what it was with no boost. Previously, before the boost of the other BTV gave up the ghost, pedal pressure was dynamite and care had to be taken to keep my head out of the windscreen.

Karp's have since told me that BTV's have no external adjustment so I'm either stuck with it the way it is, try again getting it rebuilt, or look at an aftermarket replacement system. I'm not against the latter but would really have great difficulty with a system that requires much modification to fit. I've checked the level of vacuum at idle and it's around 22" of mercury, and the system only loses about 2" overnight which seems OK. I suppose I have to do some more serious mulling over about which way to jump. Cheers, John

PRoblem #1:

Wheel cylinders "RE-sleeved" ?????
"RE-sleeving" of wheel cylinders i don't understand because OEM wheel cylinders are not sleeved to begin with. So there would be nothing to "RE-sleeve".

If they were merely just sleeved then why did u have them sleeved???? Should have been cheaper and esier just to buy new wheel cylinders.

I am wondering if the sleeves (if there really are any sleves in them) in the wheel cylinders were incorrectly installed and thus restricting brake fluid flow to the wheel cylinders.

BOTTOM LINE: Someone has fed u a big line shit about wheel cylinders, Sleeving, RE-sleeving and so forth.

Problem #2.
Quote:
"... BTV's have no external adjustment ,,,"

Can ANYONE name ANY passenger car power brake booster since 1955 that DOES have an external adjustment????

PRIOR to any brake or other wheel bearing work how well did the BTV perform??????

"Notify me of new posts in the current thread."

Three emails in a row telling me a new post in this thread.

The first thing that came to mind was "Well, I see Keith's up early this morning!"

I'm agreeing with PV8 on this one. There is no adjustment on the BTV or any other vacuum type unit I'm aware of.

As the vacuum is more than adequate, aside from something put together wrong, the only thing on the booster side I can think of that could maybe mess with boost is a partially blocked air inlet under the cleaner mesh. If they painted the can and taped the inlet holes & didn't remove all the tape that could cause problems. The only other thing I can think of on BTV side would be the residual check valve. On the original I don't think they could be installed backward but the replacements are a flat rubber disc in a retainer. I am not sure if they can be installed wrong or exactly what the symptom would be if they can--but I think you would be trying to apply brakes against the normal valve flow which would need more pressure.

If the sleeves were installed partially blocking the passage or if the diameter of the cylinders were made smaller with the sleeve, both could affect the amount of pressure needed.

Yes, Eric! But that means U're up early too. We have to be up early just to keep up with the BTV's that we don't own nor care to own for that matter. GUFWAH ha ha ha ha ha .

Be sure to check HH56's point about the BTV vent. It should not be plugged nore restricted. If it is then that would cause the hard brake pedal.