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Brakes....

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Nunyas

Nunyas

Yoda
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Hi all,
Yes, i'm new here. I found this site via google.com... the swiss army knife of the web. So far, I like what I've seen... /ubbthreads/images/graemlins/smile.gif

Anywho, I have this wierd problem with my '76 B. When I hit the brakes the engine idles up. A pretty significant amount I might add. Somewhere in the neighborhood of 500 to 600 RPMs over the normal idle speed. I'm somewhat thinking that there might be a vacume leak somewhere, but I'm not totally familiar on how the brakes work in the '76 B. When I apply the brakes I can hear what sounds like a muffled hissing sound, but I recall reading something somewhere that the brakes are servo assist and not vacume assist. So, I'm befuddled as to what's causeing my engine to idle up when I apply the brakes. Anyone here have any ideas as to what's causing it?

Also, I have the 4-speed manual transmission in my car (no over drive), and I'm having a heck of a time getting it to run right. I'm sure the running is fuel delivery/ignition related, but I'm having a hard time pin pointing the problem. The car stumbles off the line, if I don't "romp" on the gas every now and then. The stumbling off the line problem is really bad if the car has been idling for a few minutes and not fully warmed up.

Just to add to the complexity of the problem I cannot drive at freeway speeds for any sustainable amount of time. I can do short runs up to 70'ish MPH, but if I attempt to sustain a speed over 60'ish MPH (or sustain 3000RPMs for more than a minute)the car will act as though it stalled (I see the tach drop to zero RPMs) for a second or two and then pick back up. This problem makes me think fuel delivery problem, but the fact that the tachometer actually drops to 0 RPMs seems to point to electrical/ignition. The problems I have when I attempt to drive on freeways is the most irritating of the issues I have with this car. Anyone know what might cause this particular problem?

Like I mentioned before I bought this car earlier this year, and given the fact that it still runs and I only paid $750 for it (body is in amazingly good shape for the price) I still feel like I got a good deal for the car. I just need to figure out these three issues and I'll be one happy camper. /ubbthreads/images/graemlins/smile.gif
 
[ QUOTE ]
Hi all,
Yes, i'm new here. I found this site via google.com... the swiss army knife of the web. So far, I like what I've seen... /ubbthreads/images/graemlins/smile.gif

[/ QUOTE ]

Welcome to the forum, glad you found it.

[ QUOTE ]
Anywho, I have this wierd problem with my '76 B. When I hit the brakes the engine idles up. A pretty significant amount I might add. Somewhere in the neighborhood of 500 to 600 RPMs over the normal idle speed. I'm somewhat thinking that there might be a vacume leak somewhere, but I'm not totally familiar on how the brakes work in the '76 B. When I apply the brakes I can hear what sounds like a muffled hissing sound, but I recall reading something somewhere that the brakes are servo assist and not vacume assist. So, I'm befuddled as to what's causeing my engine to idle up when I apply the brakes. Anyone here have any ideas as to what's causing it?

[/ QUOTE ]

It definatly sounds like you have a vaccume leak in the brake booster.
"Vaccume assist" and "servo assist" are the same thing, its a vaccume operated servo. I really have no clue about the internal details of the things, just that when the diaphragm, or other internal parts, are leaking, it can have some odd effects on the running of the engine.

[ QUOTE ]
Also, I have the 4-speed manual transmission in my car (no over drive), and I'm having a heck of a time getting it to run right. I'm sure the running is fuel delivery/ignition related, but I'm having a hard time pin pointing the problem. The car stumbles off the line, if I don't "romp" on the gas every now and then. The stumbling off the line problem is really bad if the car has been idling for a few minutes and not fully warmed up.

Just to add to the complexity of the problem I cannot drive at freeway speeds for any sustainable amount of time. I can do short runs up to 70'ish MPH, but if I attempt to sustain a speed over 60'ish MPH (or sustain 3000RPMs for more than a minute)the car will act as though it stalled (I see the tach drop to zero RPMs) for a second or two and then pick back up. This problem makes me think fuel delivery problem, but the fact that the tachometer actually drops to 0 RPMs seems to point to electrical/ignition. The problems I have when I attempt to drive on freeways is the most irritating of the issues I have with this car. Anyone know what might cause this particular problem?

[/ QUOTE ]

It sounds like there is more going on than just the vaccume leak. You need to fix the vaccume leak, or leaks, before you move on to diagnosing other problems. Vaccume leaks will drive you nuts if you are attempting to diagnose other problems also.

[ QUOTE ]
Like I mentioned before I bought this car earlier this year, and given the fact that it still runs and I only paid $750 for it (body is in amazingly good shape for the price) I still feel like I got a good deal for the car. I just need to figure out these three issues and I'll be one happy camper. /ubbthreads/images/graemlins/smile.gif

[/ QUOTE ]

It sounds like you got a great deal, even if you have quite a few wrinkles to straigten out before it runns correctly. /ubbthreads/images/graemlins/thumbsup.gif
 
Glad you got your questions addressed so quickly and competently as it leaves me free to welcome you to the Swiss Army Knife of all forums. So welcome and keep us informed about your Super B.
 
wow... thanks for the quick reply. /ubbthreads/images/graemlins/smile.gif

I guess I'll have to analyze the exploded view diagrams of the brake system to see if I can find where the leak might be then.

Thanks again. /ubbthreads/images/graemlins/smile.gif
 
Just in case - did the PO remove the emissions system hardware? Sometimes not all the emissions vacuum ports get plugged; there's a checklist in the Octagon at the AMGB club site.

Welcome! Sure wish I could have got my 76 for $750!

Tom
 
I'm not entirely sure on everything that's been done to the car to tell you the truth. Just from the brief outings I've had under the hood/bonnet I've found that the automatic choke has been replaced with a manual choke. I see what looks like it use to be a connector that went from the valve cover to the choke (i think) has been capped off. I still have the air pump, but I don't think it's doing anything besides making more noise (pulsing gurgle type sound). I have a vaccume line that goes to what I think is the gulp valve that keeps getting blown off its manifold connection (this happens when the car run-on in the reverse direction).

I also have something odd with the fuel system (possibly emmisions related). I cannot pump fuel into the car anywhere close to "full speed" and I have to hold the pump handles at odd angles. Maybe the charcoal canister is clogged? or something related to it...

So, I THINK the PO attempted somewhat at retaining the emissions equipment, but I think their mechanic probably did a hack job on some of the stuff.... It no longer has the stock Catalytic converter on the car, instead someone fabricated an extension pipe to connect to the manifold and welded a modern "free flow" style catalytic converter into the exhaust pipes, but the pipes don't hang low enough anymore and rattle against the floor board.

Oh yeah, and my latest finding is that the timing is set to 10-15 BTC at 700 RPM....

I guess this means that I'll have to check the emissions diagrams for unplugged leaks too.... /ubbthreads/images/graemlins/laugh.gif
 
I just spent the afternoon investigating my brakes and the vaccume line associated with it. The line seems to be ok, although a little aged. What's the likely hood of the servo unit actually going bad?

On visual inspection of the unit while still installed in the car, the housing looks ok. It looks like it could actually still be an original part. Pedal effort seems to be a little on the high side, but this is in comparison to the pedal effort of more modern cars that I've had (basically the types where you tap the brakes and you know they're working).

I haven't thoroughly compared the pedal effort with and without the vaccume line conncected yet. Meaning, I haven't actually tried to drive the car without the vaccume line disconnected yet. However, with the car stationary I did test the "feel" of the pedal with the line disconected, and it seemed to be more "firm" than normal.

I'd like an opinion before I order this part, since a) MossMotors doesn't seem to carry it, and b) the B-Hive wants ~$60 for one (might not sound like much to some but i'm on a tight budget lately).
 
Odds are you have a split diaphragm inside the "booster". Not a real difficult rebuild...both moss and VB sell a kit. Unfortunately, not cheap....Moss wants around $62.00 for it. The brakes on these things, when they are working properly, will STOP these cars.

Mike
 
thanks for the tip. /ubbthreads/images/graemlins/smile.gif

but ... erm... what/who is VB? Please excuse my newbie questions, since I've only had the car for a short time and I'm still learning where all the good sources for parts.
 
If you have a vaccume pump, like a Mighty Vac, you can test the brake booster, or have a shop check it.
 
ah ... sweet... thanks /ubbthreads/images/graemlins/tongue.gif
 
Nunyas,

VB is Victoria British out in Lenexa Kansas -

https://www.victoriabritish.com

They are Moss's main competitor - Moss main office is in california and branches and auythorized resellers throughout the US

https://www.mossmotors.com

Both will send you free catalogs, or you can shop online - I've used both for parts extensively and they both offer a huge selection of parts and generally both give great customer service - Some of their stuff can be a bit pricey and sometimes you can find parts locally at a better price,

Example, Spridget front brake calipers are about $100.00 ea with a $25 core at VB and Moss doesn't offer them at all - You can buy calipers at Advance Auto for about $45 each with a $1 ( That's not a typo - ONE dollar) core charge with a limited Lifetime warranty.

Course stuff like wiper blades and oil filters can be found locally, but for stuff like replacement body panels, switches, interior kits, seals, etc. These guys have about anything you need - Just having their catalogs to look at is really neat and worth making the request.

So, make the call today and happy hunting ( Parts, that is)

Bob M
 
I finally got my catalogues in the mail earlier this week. I've ordered the repair/rebuild kit. According to UPS, I should have it by Tuesday.

Has anyone ever rebuilt one of these things? Looking through my Haynes manual, I don't see squat on rebuilding one. I'm not afraid to tear it apart and put it back together, but I'm now begining to wonder if I should have just forked out double the money and gotten an entire replacement unit.
 
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