brake booster?

[TulsaSpider]

Ok here's something new. If I am coming to a stop and sitting there my idle goes down slightly, rumbly too, and I am getting kind of a sucking sound. I replaced the hose a few weeks ago. If there is a vacuum leak wouldn't the idle go up? The old one looked kinked and collapsed and when I installed a replacement it was kinked too because of the angle. Could the hose be collapsed? Please don't say my booster diaphram is going out! If there is a vacuum leak wouldn't the idle go up?
I have my first Fiat meetup this weekend!
1978 1800

[So Cal Mark]

a small vacuum leak will cause a high idle, but as the leak becomes large you end up with a lean misfire and lower rpm

[TulsaSpider]

so would a failed diaphragm have these symptoms?

[So Cal Mark]

unfortunately, yes. With the engine idling, crawl up under the dash and press the brake pedal with your hand. If you can hear hissing around the push rod from the pedal into the booster it's time to replace the booster

[TulsaSpider]

ugh!
Ok I see a rebuild kit that Bayless has but it doesn't include the large diaphragm. Is it likely that something else has failed besides the diaphragm? How hard is the rebuild kit to do? I can't come close to a new one right now....

[TulsaSpider]

Well I was reading the post where Denise said she had eliminated the booster, and Alvon said if you wanna get an idea of how it feels just shut your engine off (don't lock the steering ) and see how it stops... I'll experiment I guess....

[So Cal Mark]

you have to do some fabrication if you want to eliminate the booster

[mdrburchette]

You can also check it by taking the hose off the booster and plugging it. Mark is right. To eliminate the booster, you'll have to remove and disassemble it to take the push rod out. You'll have to make a mounting plate for the m/c. I couldn't find any way to disassemble it except to cut it open. Then you need to be wary of the spring that's in there. Once it lets go, it could cause damage to you or surrounding objects.

[TulsaSpider]

Ok thank for the info... on the fabrication... can I do that in a day?
I see a rebuild kit that Bayless has but it doesn't include the large diaphragm. Is it likely that something else has failed besides the diaphragm? How hard is the rebuild kit to do?

[mdrburchette]

I don't know how you'd open the thing up to rebuild it! This was the hardest part of eliminating the booster and it took a few hours. I may have a good booster that could be priority mailed to you by Friday if you want to go that route. Email me your address if interested: spyderlady71@yahoo.com

[TulsaSpider]

E-mail sent!

[pauljdav]

Why cant you simply plug the vacuum port and leave the vacuum booster? Why would you need to remove it if you were not going to use it?

Paul

[mdrburchette]

My thoughts exactly...at least for a temporary fix.

[TulsaSpider]

I am sure that would be fine temporarily!

[TulsaSpider]

Denise! I have to thank you. That was a challenge to get out! When I finally got it back together and test drove it. it stops better than ever! I guess it had always been bad, but just recently started leaking. Before the pedal was always pretty stiff. Now the pedal is much softer and I have to get used to the new brakes just like it's a different car.
Somehow I lost a throttle lever clip. I knew when it fell but I never could find it... and somehow my fast idle screw fell out when I pulled off the carb for xtra clearance jeesh.. anybody have xtras? I also need the socket for a front side marker come to think of it.... All in all a successful venture Thanks Denise. I can make it to the meetup!!
Clark