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Discussion Starter #1
I just had the brake booster go out on the 91 Dodge Spirit. I was driving home from work on Thursday and when I hit the brakes at an intersection, the car went about 10-15 feet more than usual. Fortunately there was no accident. The brake light did not come on and the pedal seemed to feel normal (i.e. did not drop any further than usual). I took it easy going home and for low speed stops, everything seemed normal.

After experimenting at different speeds, I found that the problem only occurred at higher speeds/quicker stops. My first thought was that the pad material was completely gone and I wasn't getting any friction on the rotors. Friday I inspected the brakes and the pads/shoes, and they looked good. There were no leaks of brake fluid and the master cylinder fluid looked OK. I put everything back together and got ready to go for a test drive. As I was backing down the driveway, I felt the reduction in braking power and then began to hear a "rushing" or "whooshing" sound from under the dash. It was pretty obvious that the brake booster was leaking, but I checked all vacuum lines to be sure. Everything checked out fine.

For a couple of years now, I've thought of just junking out the vehicle and I thought this might be the time to do it. Instead, I checked on prices for a remanufactured booster and found out that they cost just a little more than a full tank of gas. I checked Rock Auto, Advance Auto, NAPA, and AutoZone. Even with the on-line 30% coupon for Advance, AutotZone came in the cheapest with a 20% coupon that I found on-line. Rock Auto was not competitive when the $9.95 shipping was added, even with the 5% discount code. One local AutoZone store 16 miles away had the unit in stock and after the core return, the final cost came out to be about $58. All the stores only carried a unit made (rebuilt) by Cardone (including NAPA), so store part quality was not an issue here.

I did the replacement job late Saturday and early this morning. It was not a fun job because of the very tight working area under the dash. I have previously replaced one of these on an old Toyota Celica and that one was a piece of cake. For my Spirit, the upper right nut under the dash was extremely difficult to access. I ended up removing the brake light switch, removing the lower dash panel, and lowering the steering column. I had to take frequent breaks to give my neck a break and not risk injuring myself. I got the new unit mounted and secured, installed the master cylinder, brake lines, and cruise control unit late yesterday and decided to quit. I was soaked in sweat from the heat and humidity. This morning I attached the brake pedal to the booster, re-installed the brake switch, the steering column, and lower dash trim.

It appears that the remanufactured unit has resolved the brake issue, I have preety good solid braking and no "whooshing" sound under the dash. The brake pedal travel is slightly more than previous, so I need to bleed the lines and possibly lengthen the booster rod slightly. The instructions that came with the reman unit mention that the rod may need some slight adjustment. I have no brake light showing up, so any air in the hydraulic lines is likely a very small amount.

This is actually the first time I have had (or even heard of) a brake booster failure on an EEK car. I suspect it is a rather rare occurrence. All I can say is that it is a nuisance repair because of accessibility. I guess now I have to continue driving it it for another year or so. :)
 

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The brake light is triggered by a shuttle valve, if my memory serves me. The shuttle valve sits between the two brake circuits, and triggers the brake warning light if it detects a low pressure situation in either circuit. The shuttle valve gets forced over by the higher pressure in the opposite circuit, triggering a switch which activates the light. It's a good system, but it's not foolproof, nor will it necessarily detect air in the lines.
Glad to here another AA lives to ride another day!
 

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Discussion Starter #3
Late yesterday I lengthened the booster rod by 3 revolutions and made a best effort check to insure that no contact is being made to the back of the master cylinder piston. The ideal setting has the end of the rod very close to the back of the MC piston, but it should not be contacting it or pushing on it with the brake pedal at rest.

This change made a decent improvement by shortning the brake pedal stroke. The pedal feels hard so I do not believe there is air in the lines.

I drove the car this morning and the brakes feel pretty good. The power curve has changed slightly from the OEM unit, but that is probably due to tolerance differences with the remanufactured parts. I'm leaving it as it is now.

Apparently these boosters are quite specific to the vehicle. In the catalog for a 91 Dodge Spirit, there are seperate listings for 15 in and 14 inch wheels and seperate listings for automatic and manual transmissions.

When I was searching for the part, I saw that there was a listing for a matched combination booster and master cylinder (already assembled with rod length factory set). Advance Auto, with a $40 online coupon, would have been the price winner, however, when I put the item in the cart and went to check out, the system said it was unavailable (even ship to home). Then I tried the same thing with AutoZone and got the same results (unavailable). Strangely, Rock Auto had the highest price, probably due to inclusion of the core cost. It usually is not worth the shipping costs to send the core back for heavy auto parts. NAPA may have had one available for order, but by then, I gave up and just ordered the booster, hoping the back of my MC was not leaking (it was not).
 

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John Wood said:
Late yesterday I lengthened the booster rod by 3 revolutions and made a best effort check to insure that no contact is being made to the back of the master cylinder piston. The ideal setting has the end of the rod very close to the back of the MC piston, but it should not be contacting it or pushing on it with the brake pedal at rest.

This change made a decent improvement by shortning the brake pedal stroke. The pedal feels hard so I do not believe there is air in the lines.

I drove the car this morning and the brakes feel pretty good. The power curve has changed slightly from the OEM unit, but that is probably due to tolerance differences with the remanufactured parts. I'm leaving it as it is now.

Apparently these boosters are quite specific to the vehicle. In the catalog for a 91 Dodge Spirit, there are seperate listings for 15 in and 14 inch wheels and seperate listings for automatic and manual transmissions.

When I was searching for the part, I saw that there was a listing for a matched combination booster and master cylinder (already assembled with rod length factory set). Advance Auto, with a $40 online coupon, would have been the price winner, however, when I put the item in the cart and went to check out, the system said it was unavailable (even ship to home). Then I tried the same thing with AutoZone and got the same results (unavailable). Strangely, Rock Auto had the highest price, probably due to inclusion of the core cost. It usually is not worth the shipping costs to send the core back for heavy auto parts. NAPA may have had one available for order, but by then, I gave up and just ordered the booster, hoping the back of my MC was not leaking (it was not).
Hmmm -you say a WHooshing Sound????? - My 84 Reliant 2.2 has that sound & symptoms seem similar --- no leaks , justa mushy pedal.
 

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Discussion Starter #5
That really sounds like air in the brake lines. When the booster diaphram breaks, you lose power assist, but the pedal remains firm.

If your pedal travel is more than 2 or 3 inches, you could hear that "wooshing" sound as you press down on the pedal. That might not be abnormal; i.e. most cars make that sound if you listen close enough. If after the pedal is pushed and kept down, you hear a continuous "whooshing" sound, then you likely have a bad booster (broken diaphram and continuous vacuum leak).
 

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If you look up under the dash, Stu, you should see the brake booster coming through the firewall. This is where your whooshing sound should be coming from. The brake booster has vacuum on one side when the engine is running, and ambient air on the other side. This ambient air is what actually applies the brakes. It's just like crushing a soda can by causing a vacuum inside of it (heating and then subsequently cooling it): vacuum cannot do work, but the differential in pressures can. There has to be a way for ambient air pressure to get in and out of the booster, and that air typically runs through a filter on the firewall side. You can hear it sucking and venting as you push the pedal, especially when the car off. Like John said, you won't have lousy pedal feel with a bad booster. Think of it like an extra foot on the brake-- when the booster goes, you lose the extra foot, but it should feel the same.
There are several things to fail inside the booster, but if you hear whooshing when the pedal isn't moving, something is internally wrong and the booster should be replaced.
 

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John Wood said:
This is actually the first time I have had (or even heard of) a brake booster failure on an EEK car. I suspect it is a rather rare occurrence. All I can say is that it is a nuisance repair because of accessibility. I guess now I have to continue driving it it for another year or so. :)
Prior to my membership with Allpar (a long, long time ago in a galaxy far, far away....) I had a '86 LeBaron GTS that had the brake booster fail. For a long time I could hear the air leaking when the brake pedal was depressed. Finally replaced it with the help of a friend.

As I recall it was not the easiest job, but we finally got it installed and everything working, but (why is there always a but....but I digress) the brake lights were staying on. Ended up adjusting the brake switch so that it engaged properly. I think I got the booster from NAPA. Was the only auto parts store locally. Now we have AAP and AZ.
 

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Discussion Starter #8
I often say.... "several lifetimes ago" :)

I found out on Wednesday that my cruise wasn't working and I traced it to the brake switch. I finally got it working again, but it is right on the edge of adjustment. The slightest touch to the brake pedal turns it off; yet I have push the pedal about 1/2" before the brake lights come on. I may be looking at a new brake switch and they aren't cheap for this car. There is no more adjustment left in the switch, i.e. it won't go into the retainer hole any further.

I know it sounds like I'm being nit picky on price, but I hate spending even $27 on a $450 car (salvage value) if I don't have to. LOL

On the other hand, I wouldn't bat an eye about spending $75 on the van or the RAV. :). In my mind it is all about seeing how long I can continue driving this, almost cost free, K-car... and keeping it road safe (the most important thing!).
 

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John Wood said:
I often say.... "several lifetimes ago" :)

I found out on Wednesday that my cruise wasn't working and I traced it to the brake switch. I finally got it working again, but it is right on the edge of adjustment. The slightest touch to the brake pedal turns it off; yet I have push the pedal about 1/2" before the brake lights come on. I may be looking at a new brake switch and they aren't cheap for this car. There is no more adjustment left in the switch, i.e. it won't go into the retainer hole any further.

I know it sounds like I'm being nit picky on price, but I hate spending even $27 on a $450 car (salvage value) if I don't have to. LOL

On the other hand, I wouldn't bat an eye about spending $75 on the van or the RAV. :). In my mind it is all about seeing how long I can continue driving this, almost cost free, K-car... and keeping it road safe (the most important thing!).
I hear ya John. Back when I still had my 1990 Acclaim I got to the point where I was hesitant to spend alot of money on the car. I picked it up for $300 in '03. It only had 110K miles but had peeling clearcoat on the hood - from an appearance point of view it looked horrible. But it was machanically sound underneath. Over the course of the next 4 years I spent $3500-$4,000 in regular maintenance and wear items - tires, brakes, bearings, struts, tuneup items, etc. The breaker was needing to replace the windshield. Estimate was $270 - had to get the side moldings as well. Considering the windshield for my Ram was less than $200, I decided that was enough and parked it. Eventually sold it for $200 to a gentleman who had an Acclaim with a blown engine.
 

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With the way the used car market seems to be going, though, $3-4k is not much. Nowadays, you'll spend that much on a decent used car and STILL probably have to put money into it within a year.
 

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I just looked up the KBB values on my 93 Daytona with 220K miles.

Trade-in is of course a ridiculous $369. For a car that is safe and inspectable, that's a joke. But I understand the reasoning.

Private party value, however, jumped from about $1,200 last year to $1,449, even with more miles on the car. So that's an indication of how hot the used car market is, when a 20-yr old ar in only Good condition actually increases in value as it is consumed more.
 

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I was in the room when my parents traded in our '95 Caravan. My folks just wanted to get on with buying the '05 and the trade-in value was so low that the salesman told me to go out into the lobby and get a can of soda for myself out of the machine and we would call it even... KBB on my Spirit is somewhere around $1,960.
 

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B10alia said:
With the way the used car market seems to be going, though, $3-4k is not much. Nowadays, you'll spend that much on a decent used car and STILL probably have to put money into it within a year.
Quite agree. $3K-$4K is the low end of the decent cars available. Anything priced below $1K is borderline junk. A few years ago when my son was looking for a car, most decent cars that might need a little TLC were running $3K+. Anything listed below $1500 need a lot of TLC - many should have been just hauled to the scrap yard. Fortunately a coworker was selling his '97 Mercury that was in decent shape (his Dad was a Ford mechanic). Bought it for $1,000. Have only had to replace the lower ball joints, front brakes and put a set of tires on it. It does need new rear struts/springs, but that's on hold for the moment. Only need it to last til he gets through college.

He did say he'd loved to have a Dart. Told him when he has a decent job he can buy one. Until then, the Mercury will have to do.

I did try to find a old Mopar like a Sundance, Acclaim, Spirit, but locally there were none to be found. We did buy a '97 Avenger (2.0L 5 speed manual), but we didn't realize how much work it needed - new steering rack, exhaust system, major brake repair. Ended up selling it after a few months for half of what we paid. There's an interesting story about the "after sale", but that's for another thread.
 
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