Eeek, no brakes after engine swap.
07-01-2008, 05:19 PM
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Eeek, no brakes after engine swap. 1993 Firehawk ~60K miles
LE2 heads, LE1HL cam (same setup I had in my 350; and it stopped great)
So we got the new forged 355 in; wonderful, runs great.
The mechanic noticed that the brake hoses needed replacing so I ordered
a set of braided lines from Bunkart (I have stock LT1 front calipers and LS1 rears)
After bleeding the lines, bleeding some more and then bleeding again,
the pedal still drops to the floor as soon as the engine is started.
It's nice and firm with the motor off.
There's plenty of fluid in the reservoir. No fluid leaks or puddles.
ABS was properly bled as well.
I happened to pick up a known good M/C with a line lock and ABS bypass at a good price.
Installed it, no luck.
(But at least now I have a line lock)
Suggestions?
All I can think is that either the booster went bad or there's still a stubborn
pocket of air in there somewhere. I don't see how a booster goes bad with
a car just sitting in a garage for 3 months, but who knows. The air seems
more likely, maybe I'm missing something in the bleed process.
LE2 heads, LE1HL cam (same setup I had in my 350; and it stopped great)
So we got the new forged 355 in; wonderful, runs great.
The mechanic noticed that the brake hoses needed replacing so I ordered
a set of braided lines from Bunkart (I have stock LT1 front calipers and LS1 rears)
After bleeding the lines, bleeding some more and then bleeding again,
the pedal still drops to the floor as soon as the engine is started.
It's nice and firm with the motor off.
There's plenty of fluid in the reservoir. No fluid leaks or puddles.
ABS was properly bled as well.
I happened to pick up a known good M/C with a line lock and ABS bypass at a good price.
Installed it, no luck.
(But at least now I have a line lock)
Suggestions?
All I can think is that either the booster went bad or there's still a stubborn
pocket of air in there somewhere. I don't see how a booster goes bad with
a car just sitting in a garage for 3 months, but who knows. The air seems
more likely, maybe I'm missing something in the bleed process.
07-01-2008, 06:25 PM
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1. Remove the Antilock Brake System (ABS) motor pack lower cover.
2. Mark all 3 gears with a marker.
3. Fully depress the brake pedal, watch for gear movement.
4. The motor gears should not move.
5. Replace the ABS motor pack if the gears move.
Vernon
2. Mark all 3 gears with a marker.
3. Fully depress the brake pedal, watch for gear movement.
4. The motor gears should not move.
5. Replace the ABS motor pack if the gears move.
Vernon
07-01-2008, 10:30 PM
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Then check for frozen caliper pins holding the pads slack without pedal or pumping, if there fine it's the booster. If it were air your pedal wouldn't feel right engine off either.
Vernon
Vernon
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07-21-2008, 07:46 PM
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*sigh* Nothing positive.
I had the car trailered from the shop who installed my motor (let's call it Shop A)
which happened to be 70min or so from here to a local shop (shop B) who
does most of my exhaust, brake and other work for me and happens to be 10 min from here.
I expected to have the brakes fixed and be on my way.
It cost me $100 to trailer it, but I figured it might buy be a month or so since
Shop A was only able to work on my car one day a week. (long story)
To my horror, I found that the car vibrates very badly. A problem I thought
had been resolved with the machined flexplate we had installed at Shop A.
(We machined it to match the flywheel used on the motor's previous car)
I'm talking VERY bad vibration, like "holy crap, this thing is going to fly apart" kind of vibration)
Now Shop B is more than qualified to troubleshoot, but also quite busy.
So my car becomes a project to be done between their normal customer flow
since it's rather complex. That also means that I'm going to end up paying
more to have the problem fixed since Shop A was operating under a flat rate
and Shop B will have an hourly rate.
(does your head hurt now? ... mine does)
So I've asked Shop B to begin removing drive train components starting with
the drive shaft and moving forward until the vibration goes away.
If it turns out that the motor and flexplate do not balance properly, I'm
back to square 1 and a whole lot poorer. We'll have to pull the motor and
either have it balanced or build something else. (I was considering 383)
Shop A has a whole load of personal issues going on and wouldn't be able
to do much for me in the immediate future, but has offered to build and
install a 383 for me at a substantial discount if I can wait a month or so.
Keeping in mind that I bought the motor and brought it to shop A, that's not a horrible deal.
In retrospect, buying a used motor and having it rebuilt by an individual
wasn't the smartest thing I've ever done.
Oh, and just to make things more interesting, the rotating assembly in my
355 is forged, but is actually 1PC RMS SBC. Which isn't a huge problem other
than it being very custom and somewhat difficult to unload if I had to tear
the whole thing apart and swap in a 383 rotating assembly (might as well
pick up a little bit of TQ for my pain)
I had the car trailered from the shop who installed my motor (let's call it Shop A)
which happened to be 70min or so from here to a local shop (shop B) who
does most of my exhaust, brake and other work for me and happens to be 10 min from here.
I expected to have the brakes fixed and be on my way.
It cost me $100 to trailer it, but I figured it might buy be a month or so since
Shop A was only able to work on my car one day a week. (long story)
To my horror, I found that the car vibrates very badly. A problem I thought
had been resolved with the machined flexplate we had installed at Shop A.
(We machined it to match the flywheel used on the motor's previous car)
I'm talking VERY bad vibration, like "holy crap, this thing is going to fly apart" kind of vibration)
Now Shop B is more than qualified to troubleshoot, but also quite busy.
So my car becomes a project to be done between their normal customer flow
since it's rather complex. That also means that I'm going to end up paying
more to have the problem fixed since Shop A was operating under a flat rate
and Shop B will have an hourly rate.
(does your head hurt now? ... mine does)
So I've asked Shop B to begin removing drive train components starting with
the drive shaft and moving forward until the vibration goes away.
If it turns out that the motor and flexplate do not balance properly, I'm
back to square 1 and a whole lot poorer. We'll have to pull the motor and
either have it balanced or build something else. (I was considering 383)
Shop A has a whole load of personal issues going on and wouldn't be able
to do much for me in the immediate future, but has offered to build and
install a 383 for me at a substantial discount if I can wait a month or so.
Keeping in mind that I bought the motor and brought it to shop A, that's not a horrible deal.
In retrospect, buying a used motor and having it rebuilt by an individual
wasn't the smartest thing I've ever done.
Oh, and just to make things more interesting, the rotating assembly in my
355 is forged, but is actually 1PC RMS SBC. Which isn't a huge problem other
than it being very custom and somewhat difficult to unload if I had to tear
the whole thing apart and swap in a 383 rotating assembly (might as well
pick up a little bit of TQ for my pain)
07-21-2008, 07:49 PM
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Fortunately, I have the original motor from my car sitting in the garage.
So I have a block I can machine and use as a 383 if I wanted to without having
to gut the 355. Although if I sold the 355, the buyer would have to tear it down and
have it balanced, so I'm not sure that's a huge advantage.
So I have a block I can machine and use as a 383 if I wanted to without having
to gut the 355. Although if I sold the 355, the buyer would have to tear it down and
have it balanced, so I'm not sure that's a huge advantage.
