At 12:46 PM 4/25/00 -0700, David Ebel wrote:
>Well everyone seams to doubt the proportioning valve is the problem, but it
>really looks that way to me. The brakes light is on in the car, and we know
>that the drum brakes are adjusted correctly. Its just that a very small
>amount of brake fluid (and pressure) is getting to the rear brakes. Lack of
>power = power booster / lack of fluid seams to me that the valve has sensed
>a drop in pressure and to keep the system running, it has diverted power to
>the front and virtually shut it off to the back. It is also interesting
>that both rear brakes function (or do not rather) identically. I believe
>that I have to reset the proportioning valve - whatever that means. Anyone
>else want to shed some light?
Dave,
If the brake light is on, then either the porportioning valve needs to be
centered, or the emergency brake switch has failed. (I don't remember seeing
a swith on my ememgency brake.)
Anyone with a functioning car? If you ememgency brake is pulled up, does
the brake light on the dash come on? I know it does on several of my other
cars. But since I just put the emergency brake in #887, I don't remember
seeing a switch to sense that it is on.
Anyway, back to your problem Dave. I looked up the info on the
proportioning
valve in my AMC books. The manual states:
Section 5 states:
"In the event of a lead or other malfunction in either circuit, the
piston is displaced by the loss of pressure and completes an electrical
circuit to provide the driver with a visual warning by means of an
indicator light."
Section 6 states:
"This valve has three functions: (a) pressure differential valve
similar to that described in Section 5, (b) a pressure regulating
valve to prevent the rear brakes from locking before the front ones
and (c) a front brake pressure metering valve which allows rear brake
circuit pressure to build up while reducing front brake circuit pressure
until the rear brake shoe return spring tension has been overcome."
"Whenever the piston in the pressure differential valve is displaced,
it has to be recentered. To do this, turn the ignition switch on and
press the brake pedal a time or two."
This is a NON repairable item!
On my Spitfire, when the piston is displaced to center it, you turn on the
ignition as above, but you "carefully/slowly" bleed the side opposite the
last one done. This will let the piston come back to center. Have your
helper (that is pressing the brakes for you) very slowly press the brake
pedal, and watch the light on the dash. When it goes out, he stops pressing
on the brake, (but doesn't release his pressure) and tells you so you can
shut off the bleeder.
Try either method and keep us informed.
John
>
>
>-----Original Message-----
>From: Olenick, Jamison [mailto:Olenick@ssims.nci.nih.gov]
>Sent: Tuesday, April 25, 2000 12:32 PM
>To: Bricklin (E-mail)
>Subject: RE: Power Booster
>
>
>Dave,
> I remember replacing the power brake booster and the master cylinder on
>#1080 (75). If I remember correctly I just used the NAPA part # the John
>Blair has on the Cross-reference and it fit perfectly....although not the
>easiest thing to replace. (I think that I needed an extra set of hands)
> As for your other drum problems. I had the same problem recently on a
>complete brake rebuild on a Grand-Am. When we would try to bleed the brakes
>I found that just leaving the bleeder open and holding my finger over it
>till it got pressure and then closing it worked best. If after that I would
>try to bleed then the first try would be full of pressure and the second
>would just dribble (and the pedal was not released before I shut the
>bleeder). NOTE: I do not claim to be a brake expert.
> Hopefully someone will be able to help you better with the rear brakes.
> My guess is that it is just an adjustment of some sort....whether inside
>the drum (that adjustment screw thing where the rear shoes meet at the
>bottom...or something else. Try holding your finger over the open bleeder
>and then pumping the brakes, and then close it when you get some pressure.
> I doubt the proportioning valve is the problem....FWIW
>
> Jamie
>
>> -----Original Message-----
>> From: David Ebel [SMTP:david.ebel@visitalk.com]
>> Sent: Tuesday, April 25, 2000 2:01 PM
>> To: Bricklin (E-mail)
>> Subject: Power Booster
>>
>>
>>
>> Does anyone have one, or a part number for one that fits right? The
>> rod distance is what I am having a problem with. Thanks
>>
>> Dave
>>
>> -----------------------------------------
>> David Joseph Ebel
>> david.ebel@visitalk.com
>> visitalk.com - Website Developer
>> Office: (602) 850-3402 | Cell: (602) 315-9585
>> Bricklin Owner #841 <www.davidebel.com>
>
>
John T. Blair WA4OHZ email: jblair@exis.net
Va. Beach, Va Phone: (757) 495-8229
48 TR1800 48 #4 Midget 65 Morgan 4/4 Series V
75 Bricklin SV1 77 Spitfire 71 Saab Sonett III
Morgan: www.team.net/www/morgan
Bricklin: www.bricklin.org
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