Vacuum pumps.

Larry L.

Member
Lifetime Supporter
#21
Update:

Ooooooookaaay...after having had Z-E-R-O luck getting any of the three replacement 'brand X' Spanish-made pumps to work (not to mention the 2 or 3 other pumps I've bought from other manufacturers), I've found one that worked as advertised out of the box. Time will tell if things STAY THAT WAY...but, for now at least things look promising.

It's the "Black Bandit" 'pump from Leeds Brake Company...but, I say again - it's worked "so far"...as in 'worked during its initial test run'. A couple of other brand's pumps worked 'after a fashion' over a 10 day period-or-so before deciding to 'take the dirt nap'...so...

If this unit pukes - yeeeeew will be the first to know...


Bandit Series Brake Booster Vacuum Pumps | Vacuum Brake Boosters




(Thanks, Rick!)
 
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Larry L.

Member
Lifetime Supporter
#22
'Follow up report:

'Took the "Bandit"-equipped hot rod out for a cruise around town...on and off the brakes every few seconds for traffic lights and stop signs...total 'putt around' time about 3 qtrs of an hour.

Vacuum stayed between 18 and 25 inches the whole time (the advertised parameters of the unit). The INSTANT the vac gauge read 18 inches, the unit lit off, pulled to 25 and shut off...each time, every time, all the time. Added bonus - it's Q-U-I-E-T! With the engine OFF you can't even hear the darned thing running when inside the passenger compartment. 'Have to strain to hear it run when OUTSIDE the vehicle.

So, thus far it D-O-E-S exactly what Leed's webpage SAYS it'll do.

I'm a happy camper...
 

Rick Muck- Mark IV

Member
GT40s Sponsor
#23
So Greg hooked you up OK? Of course this is a pump repurposed from another application (as are most all of these types of products) but knowing the people involved and having had "hands-on" this item I was comfortable in recommending it.

Glad it works!
 

Larry L.

Member
Lifetime Supporter
#24
So Greg hooked you up OK? Of course this is a pump repurposed from another application (as are most all of these types of products) but knowing the people involved and having had "hands-on" this item I was comfortable in recommending it.

Glad it works!

I didn't need to bother Greg, Rick. 'Saw the unit was self contained...'had a two wire and one hose install...'provides between 18 and 25 inches of vac continually and that was all I needed to know!

Bottom line: one indeed does get what one pays for...in this case $379.95 for the "Bandit" vs. around $200.00 or whatever the "stickers" were on the previous unit/units.

Thanks again, Rick!
 
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Dr. Bob Woods

Member
GT40s Supporter
#25
I'm interested in the UP28 vacuum pump, but the Bandit sounds good too. Any update on the measurements of the min and max vacuum levels? How many amps does it draw at max? How much airborne and chassis-transmitted noise?

I have a small block Ford bored and stroked to 363 with a high performance cam. At idle I get about 12 inches of mercury vacuum (MAP of 60 kPa or 40 kPa vacuum). My boosters don't work at all whether they are connected to vacuum or not. I wish I could find more technical details on the Lockheed/Delphi boosters. For example, how much vacuum is required to make them start to work, and at what vacuum will they have the full 1.9 boost ratio? Anybody have technical details of the boosters?

Incidentally, according to my analysis, I have had to change my rear calipers from 1.0" pistons to 1.25" pistons to reduce the nearly 1000 psi required to stop at 1 g with the original Tornado system. I had to mount a separate parking brake since the 1.25" calipers didn't have a built-in parking brake. I will also change my front master cylinder from 0.700" to 0.625" to better balance the front/rear pressure bias. With these changes, the pressures will be 650 and 600 psi with a 53% to front bias bar setting for braking at 1 g. If the booster works, it will take 51 pounds on the foot to stop at 1 g. If the booster doesn't work, it will take 97 pounds.

I will be very interested to hear from other people having trouble with brakes and brake boosters, please.

-Bob Woods
 
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Larry L.

Member
Lifetime Supporter
#26
...but the Bandit sounds good too. Any update on the measurements of the min and max vacuum levels? How many amps does it draw at max? How much airborne and chassis-transmitted noise?
Haven't driven the hot rod since late last August, but, when I put it in storage, the Bandit still performed as stated in post #22; to wit: Quiet as a mouse whether one's inside or outside the vehicle - engine running or not (one really DOES need to 'pay attention' to hear it)....Vac is always 18-25 (with occasional 'spikes up to around 27 on the top end for some reason...according to the vac gauge anyway). There is no "chassis-transmitted" noise at all in the hot rod if only because the unit is 'rubber mounted' to the firewall beside the radiator. 'No chassis contact at all.

'Have not checked to see how many amps it draws nor do I recall seeing that info mentioned anywhere on Leed's website OR in the paperwork included in the Bandit's shipping box, but, then again, I wasn't looking for it either.

Leeds contact info is:

1-716-852-2139 (Mon-Fri 9 A.M. - 4:30 P.M. EST)
[email protected]


(Edit)
My boosters don't work at all whether they are connected to vacuum or not.
Note: The Bandit is a stand alone unit. It's not designed to work in concert with any other vac sources. Its 'output' hose is routed directly to the power brake booster's check valve fitting.

I've designed/installed a 'bypass' routing setup (manually engaged) that reroutes the vac source to the intake manifold in case the Bandit fails.
 
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Dr. Bob Woods

Member
GT40s Supporter
#28
Larry, thanks for the response.

John, Cliff, and others, what is your experience with the vacuum boosters?

It appears to me that if the booster doesn't work until it gets enough vacuum and then will work with adequate vacuum, then the boost gain might be proportional to the vacuum level. If so, then the pedal or braking g's will feel different when the vacuum varies between the 18 and 25 inches Hg (Bandit says 15 - 24). Even if the gain is constant with varying vacuum levels, at least the response time will vary. For the street, that might be ok; but, if you are racing, I would want to know what the brakes were going to do BEFORE I get to the corner (I'm a late braker).

So what do you guys feel in the brake pedal (or braking g's) with the maximum and minimum vacuum levels?

The Bandit draws 11 amps. Do you know what the UP28 draws and what the vacuum limits are for it?

-Bob Woods
Tornado GT40 in Texas
 

Larry L.

Member
Lifetime Supporter
#29
...Even if the gain is constant with varying vacuum levels, at least the response time will vary. For the street, that might be ok; but, IF YOU ARE RACING, I would want to know what the brakes were going to do BEFORE I get to the corner...
I hadn't even considered that 'cause mine is 'street use' only...but, I'm sure you're 100% correct.
 
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